#⚛️┃physics | Official Unity Discord | Page 35

lapis plaza Mar 19, 2019, 3:17 PM

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@tropic hamlet DOTS physics api is different

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you can swap between Unity Physics and Havok

tropic hamlet Mar 19, 2019, 3:17 PM

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i use physx in a light manner, I just need really good spherecast, raycast, convex colliders and rigidbody basically. everything else I code myself fine with the fundamental building blocks above

lapis plaza Mar 19, 2019, 3:17 PM

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but PhysX will stay on the gameobject side setup with old components

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did you watch the keynote for physics?

tropic hamlet Mar 19, 2019, 3:17 PM

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yes but I cannot hear, so...

lapis plaza Mar 19, 2019, 3:18 PM

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oh right, I forgot

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well, the blog post is fairly good

tropic hamlet Mar 19, 2019, 3:18 PM

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any info you can add is super welcome <3

lapis plaza Mar 19, 2019, 3:18 PM

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https://blogs.unity3d.com/2019/03/19/announcing-unity-and-havok-physics-for-dots/

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basically swapping between those two new alternatives is just a switch in script

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I'd hope someone makes DOTS api compliant PhysX setup too

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if not by Unity then by nvidia itself as they got the physx 4 plugin thing going on now

tropic hamlet Mar 19, 2019, 3:20 PM

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the physics thing cannot be coded with regular c# ?

lapis plaza Mar 19, 2019, 3:20 PM

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but in the end, I'm really hoping Unity Physics will be enough for everything on my needs 😄

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Unity Physics is c# package, you can use it without ECS but it works on ECS

tropic hamlet Mar 19, 2019, 3:20 PM

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i would expect that to still be possible since with physics you can close the sim for most things, and only interfere when needed...

lapis plaza Mar 19, 2019, 3:21 PM

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I mean, from what I've understood, they want the new DOTS physics setup to work for traditional nonECS projects

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despite the physics code itself runs on ECS

tropic hamlet Mar 19, 2019, 3:21 PM

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porting my game to ECS is viable but I am one man, I cannot afford to extend dev times with unknowns, and I have a strict deadline with Sony in august

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(for an alpha playable not a final)

lapis plaza Mar 19, 2019, 3:21 PM

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well, if you are not really going for ECS, just stick with PhysX

tropic hamlet Mar 19, 2019, 3:21 PM

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so i can play a little but it needs to be quite clearly an api not changing too much

lapis plaza Mar 19, 2019, 3:22 PM

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Unity Physics will definitely not be ready by summer

tropic hamlet Mar 19, 2019, 3:22 PM

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I played hard with ECS when it came out but it changed rapidly and I couldn't afford to keep changing with

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will havok be ready sooner?

lapis plaza Mar 19, 2019, 3:22 PM

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they launch integration on summer

tropic hamlet Mar 19, 2019, 3:23 PM

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what advantages are there for using havok over physx?

lapis plaza Mar 19, 2019, 3:23 PM

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nobody here knows 😄

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besides Unity staff

tropic hamlet Mar 19, 2019, 3:23 PM

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well classically havok has been deterministic, the only physics engine guaranteed to be actually if you wanted it to be

lapis plaza Mar 19, 2019, 3:23 PM

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if the API is more exposed, it can be seen as advantage

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I saw that Unity Physics samples had all kinds of modification support

tropic hamlet Mar 19, 2019, 3:23 PM

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so histortically I can see why it's been the stronger mp bet

lapis plaza Mar 19, 2019, 3:23 PM

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that looked super fancy

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as that's what I've been asking for Unity's physx integration for ages now

tropic hamlet Mar 19, 2019, 3:24 PM

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i like contact modification.

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i need that.

lapis plaza Mar 19, 2019, 3:24 PM

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oh, if you do MP, then the new package will be nice

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eventually anyway :p

tropic hamlet Mar 19, 2019, 3:24 PM

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i want to just do my char controller before it moves not correct it after. i do correct it after really, really well but it would be all kinds of perfect just to mod the contacts, you know?

lapis plaza Mar 19, 2019, 3:24 PM

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for the modification samples:

📎 unknown.png

tropic hamlet Mar 19, 2019, 3:25 PM

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oh....

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that's interesting eh

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has xmas come early for us ? no it hasn't since we wait for summer

lapis plaza Mar 19, 2019, 3:29 PM

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I'm super happy

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HPC# Physics + Granite

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didn't expect the latter

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also, I don't really care for Havok itself

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at least not with current info

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they've hinted it'll be additional payment

tropic hamlet Mar 19, 2019, 3:30 PM

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I'm kind of dissapointed about the whole physics thing because yant is doing all this work and it's being replaced, basically... why is nvidia doing a plugin separately?

lapis plaza Mar 19, 2019, 3:30 PM

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but no details how much, so hard to get excited about something you don't know the details about

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I'd guess they knew about this and wanted to cover the physx availability

tropic hamlet Mar 19, 2019, 3:31 PM

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also granite and their patents will help. amplify had to pull theirs because of granite's patents.

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(don't quote me ;) )

lapis plaza Mar 19, 2019, 3:31 PM

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you probably heard Unity acquired them?

tropic hamlet Mar 19, 2019, 3:31 PM

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ofc

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but i'm talking about amplify

lapis plaza Mar 19, 2019, 3:31 PM

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I know

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kinda sucks for amplify

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at least Unity doesn't have to work around those patents now ;D

tropic hamlet Mar 19, 2019, 3:32 PM

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i mean, amplify couldn't go further with theirs anyway as it crossed the patent line and while graphene didn't do the nasty it wasn't worth it

lapis plaza Mar 19, 2019, 3:32 PM

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AT and Granite has really similar implementation though

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so I'm not even surprised

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I've tried both

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and they work exactly alike from the surface anyway

tropic hamlet Mar 19, 2019, 3:32 PM

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well i have some inside knowledge but i think it's irrelivant now as we get the patent backed toys...

lapis plaza Mar 19, 2019, 3:32 PM

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it's like someone just copy/pasted the implementation

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how the atlases worked etc

tropic hamlet Mar 19, 2019, 3:33 PM

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and the company that did it was basically just working as bespoke contractors so any plugins were left to rot

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AAA was fine with it due to them having priority

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but plugins kinda were really left behind

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now its bought by unity we can expect some magic

lapis plaza Mar 19, 2019, 3:33 PM

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yeah

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not expecting anything in short term tho

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maybe for 2019.3 earliest

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if even that

tropic hamlet Mar 19, 2019, 3:34 PM

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really tho unity just needs the right to use the tech and can easily source staff to move forward quick

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so the real stumbling block was having them to begin with

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its all good

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thing is with this stuff, is... its still kinda really hard to author textures that scale

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we have done it a lot in the past and the storage, the processing is harsh

lapis plaza Mar 19, 2019, 3:37 PM

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authoring 4k maps is fine

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imagine you have any open world game with high resolution textures

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VT lets you do more streamlined and naive pipeline

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no need to fiddle with shaders to optimize the materials, just texture it on substance painter etc and deploy

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same with scans

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of course your installation size will be huge

tropic hamlet Mar 19, 2019, 3:41 PM

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well I still need terain texture caching and splatting a terrain is a faster workflow than texturing every part uniquely. i get the mip streaming but unity already has it

lapis plaza Mar 19, 2019, 3:42 PM

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@tropic hamlet since you are around, could you go close this thread? 😄 https://forum.unity.com/threads/dots-based-physics.646840/#post-4335802

tropic hamlet Mar 19, 2019, 3:43 PM

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ok

lapis plaza Mar 19, 2019, 3:43 PM

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I didn't want to report it as it's not really breaking any forum terms

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someone just happened to make another thread before the official thread was live

tropic hamlet Mar 19, 2019, 3:43 PM

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done

lapis plaza Mar 19, 2019, 3:43 PM

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thanks

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Still working out the details regarding the Havok Physics integration. I'll be following up with info here and in another blog post once we've locked down all the details.

Yes, so we're using the exact same data layout in the Editor which means when you author a bunch of content you're only building it once. For example, if I set up my environment with a bunch of physics components and I am using Unity Physics and then I decide to use Havok Physics, I don't have to redo every object to use a set of Havok components. Similarly, any game code or scripting logic you've written to use Unity Physics will work just the same if you swap in the Havok Physics backend.

Regarding differences, they're both intended to be high-performance physics solutions, they just solve different production needs. Unity Physics' key points are the fact that it's a C# package so you can easily get in there, look at the source code, and modify it to your heart's content. It's also stateless, so instead of using caches, we rely on brute force optimizations to make it more compatible with things like network rollback architecture. Havok Physics is integrated using the Havok engine and uses caching so you're able to squeeze more performance out of complex scenarios and get much more stable simulations for things like stacking, lots of rigid bodies, etc. Hopefully, that helps explain it a bit more but let me know if you'd like more details!

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from: https://forum.unity.com/threads/unity-physics-discussion.646486/#post-4336105

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I do hope they fix the stacking on Unity Physics regardless 😄

tropic hamlet Mar 19, 2019, 3:51 PM

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I have decent stacking

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but you have to still watch your masses

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don't stack anything 2x heavier on anything else etc

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preferbly the lower ones should have higher masses

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classic physx nonsense :D

lapis plaza Mar 19, 2019, 3:52 PM

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oh I meant for the new package

tropic hamlet Mar 19, 2019, 3:53 PM

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well hopefully answers will come

lapis plaza Mar 19, 2019, 3:53 PM

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https://cdn.discordapp.com/attachments/497874303463850004/557402971269496832/Unsettling.gif
https://cdn.discordapp.com/attachments/497874303463850004/557459297412317184/exampleMovement.gif
https://cdn.discordapp.com/attachments/497874303463850004/557460050717704192/mass.gif

tropic hamlet Mar 19, 2019, 3:53 PM

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for me I do want a LOT of simple physics objects bouncing around like debris etc

lapis plaza Mar 19, 2019, 3:53 PM

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yeah, I'm not in a hurry for that 😄

tropic hamlet Mar 19, 2019, 3:53 PM

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er ... that doesn't seem timestepped and interpolated at all

lapis plaza Mar 19, 2019, 3:54 PM

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yeah we covered that earlier

tropic hamlet Mar 19, 2019, 3:54 PM

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seems like its tied to framerate

lapis plaza Mar 19, 2019, 3:54 PM

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yes

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it's a bug

tropic hamlet Mar 19, 2019, 3:54 PM

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lol.

lapis plaza Mar 19, 2019, 3:54 PM

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they run it at each update with fixedDeltaTime

tropic hamlet Mar 19, 2019, 3:54 PM

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I was just frowning then!

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well would need substepping

lapis plaza Mar 19, 2019, 3:54 PM

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it's probably because they recently moved the ECS simulation group from fixedupdate to update

tropic hamlet Mar 19, 2019, 3:54 PM

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unless it's purely visual one cannot just run it at delta time

lapis plaza Mar 19, 2019, 3:55 PM

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if you scroll back few pages here, you'll see my rants about relying on Unity side code for fixed timesteps

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I really really don't like it

tropic hamlet Mar 19, 2019, 3:55 PM

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I see well if we can choose when each world is stepped it should be fine i think

lapis plaza Mar 19, 2019, 3:55 PM

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but one can do their own stepping of course

tropic hamlet Mar 19, 2019, 3:55 PM

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i do prefer to run my physics in a fixed loop so my characters and everything run the same (mostly) regardless of hardware

lapis plaza Mar 19, 2019, 3:56 PM

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oh, I do like fixed timesteps for physics

tropic hamlet Mar 19, 2019, 3:56 PM

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I even have my combat logic in the same fixed update loop

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because I like the reliability regardless of framerate for that

lapis plaza Mar 19, 2019, 3:56 PM

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I meant that I don't like that they run the ECS physics stepping code on closed source Unity side

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as they could just do it on ECS fully

tropic hamlet Mar 19, 2019, 3:56 PM

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(anims have colliders and thus need to be stepped though at specific resolution like streetfigher etc)

lapis plaza Mar 19, 2019, 3:57 PM

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now things rely on many things: Unity Physics rely on Entities package for simulation groups I think

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and entities relies on Unity's internal code for fixed timesteps

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they are pointless dependencies if you do pure ECS

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well, not the entities one but the engine side thing

tropic hamlet Mar 19, 2019, 3:58 PM

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what portion of unity's own hpc# physics are engineered by havok?

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I ask so I can be reassured there's a pedigree behind it at least.

lapis plaza Mar 19, 2019, 3:58 PM

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no idea, they haven't really been clear on public statements on that

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in the keynote it sounded like Havok implemented the whole thing

tropic hamlet Mar 19, 2019, 3:58 PM

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if it's just unity's own stuff, then I predict a way longer path to stability

lapis plaza Mar 19, 2019, 3:58 PM

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and in blog post it sounded like it was purely Unity's internal thing

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I'm fairly certain that the truth is somewhere in the middle

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and the foundation seems really solid

tropic hamlet Mar 19, 2019, 3:59 PM

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yeah I think we'll be waiting a while. whenever Unity's rolled it's own alternative to something you can get off the shelf, it's ALWAYS been one guy or two guys and it's not given the attention it needs

"it's open source" can also mean "we've only got one guy on it"

lapis plaza Mar 19, 2019, 3:59 PM

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so even if Havok is no longer involved, it's not really a huge issue

tropic hamlet Mar 19, 2019, 3:59 PM

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so open source doesn't mean shit tbh

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not without backup

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else you might as well invest too much work of your own in it

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I'm not knocking unity, just saying... it's not the first time we've been shown promising things then had to wait forever then seen it depreciated in the end.

lapis plaza Mar 19, 2019, 4:01 PM

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what is REALLY cool about Unity Physics at this state is that it's really human readable and super focused thing, it implements the bare minimum

tropic hamlet Mar 19, 2019, 4:01 PM

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yeah and my game needs more than the bare minimum

lapis plaza Mar 19, 2019, 4:01 PM

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so if anyone is interested on how physics engines work, this is a great resource

tropic hamlet Mar 19, 2019, 4:01 PM

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I'm interested in shipping my game > all

lapis plaza Mar 19, 2019, 4:02 PM

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well, they do all the basic collider types, queries, narrow+broadphase, joints

tropic hamlet Mar 19, 2019, 4:02 PM

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I'm up fo havok if the price is right but haven't any interest in the unity physics UNLESS.... unless it's the fastest option in which case I will look super closely at it

lapis plaza Mar 19, 2019, 4:02 PM

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what I mean, they cover all the basics already

maiden grove Mar 19, 2019, 4:02 PM

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Havok licenses are in the O($100k) per game range - I do wonder how this will wind up being licensed

tropic hamlet Mar 19, 2019, 4:03 PM

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havok to be fair is usually licensed by AAA and comes with bespoke havok staff support

maiden grove Mar 19, 2019, 4:03 PM

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do I get to customize the staff?

tropic hamlet Mar 19, 2019, 4:03 PM

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the unity one for unwashed masses like us should probably be absorbed as pro license / affordable service

lapis plaza Mar 19, 2019, 4:04 PM

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I'm still so much against the pro deal

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it's what I really disliked about Unity on Unity 4

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physics isn't a service either

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it's a core game engine feature

tropic hamlet Mar 19, 2019, 4:06 PM

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I'm actually a little unhappy with all this:

unity's own physics doesn't work with gameobjects so i'd need to code my game character in dots
physx seems to be heading to dll land and moved out of native unity... it will only have updates, so no guarantees on future console support etc, no guarantees anywhere
havok is licensed and unity doesn't have a plan to make it's own hpc# physics as performant. likely they could, but unity staff did mention you would use havok for bigger higher performing scenarios

so this basically is a trio of not so hot scenarios

lapis plaza Mar 19, 2019, 4:08 PM

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yeah, I'm least excited about Havok option

tropic hamlet Mar 19, 2019, 4:09 PM

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the best option here, is obviously going to be using havok. this is logical from unity's partnership and the implication it would outperform the other options.

lapis plaza Mar 19, 2019, 4:09 PM

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because if that's the best option, it means the options regular users get will be way worse

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and there will not be need to optimize the built-in package further

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as AAA can just use Havok

tropic hamlet Mar 19, 2019, 4:09 PM

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thats precisely what is happening so I will move to havok if I can.

lapis plaza Mar 19, 2019, 4:09 PM

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I'm fairly certain that havok being there is for AAA

tropic hamlet Mar 19, 2019, 4:10 PM

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if I cannot afford it then I will have to run the physx dll guantlet in the long term

lapis plaza Mar 19, 2019, 4:10 PM

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yeah, will see how this plays out

tropic hamlet Mar 19, 2019, 4:10 PM

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I do not believe that the hpc# physics will be anything except a default option

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I think we're 100% seeing the start of the end for physx, agreed?

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it could take a long time

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but i think as it'll go external (no reason why it wouldn't) then we'll have to just accept that

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"

📎 unknown.png

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as expected

lapis plaza Mar 19, 2019, 4:13 PM

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we'll see

tropic hamlet Mar 19, 2019, 4:16 PM

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i agree with your pro statement but you aren't doing a correct comparison

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before with indie/free you couldn't add the missing features without pro. pro was the only option

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now u can though, take a service without taking pro

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so it doesn't block anyone like the old days, even so I agree it would screw up my team

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:D

lapis plaza Mar 19, 2019, 4:18 PM

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well

tropic hamlet Mar 19, 2019, 4:18 PM

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So it looks like realistically we use hpc# or physx, and both are in uncomfortable places.... looks like we better start forking gitting on with it ;)

lapis plaza Mar 19, 2019, 4:18 PM

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yeah

tropic hamlet Mar 19, 2019, 4:19 PM

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i guess we best get our hands dirty with open source

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i can't see the other secure affordable option

lapis plaza Mar 19, 2019, 4:19 PM

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I'm fine with that

tropic hamlet Mar 19, 2019, 4:19 PM

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and we both know that's a long road

pearl warren Mar 19, 2019, 4:19 PM

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I'm affraid this is really really bad

lapis plaza Mar 19, 2019, 4:19 PM

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having Unity Physics sources available now is a blessing

pearl warren Mar 19, 2019, 4:19 PM

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Unity Physics will not be as good as either option

lapis plaza Mar 19, 2019, 4:19 PM

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this saves me a ton of time

pearl warren Mar 19, 2019, 4:19 PM

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and havoc will be big dollars

tropic hamlet Mar 19, 2019, 4:19 PM

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it means physx will become external closed box and not further developed, this is logical

lapis plaza Mar 19, 2019, 4:20 PM

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well, PhysX is open source, so is Bullet, so is Newton Dynamics, ODE etc

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you can port things you need to Unity thing

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if you have time and understanding 😄

tropic hamlet Mar 19, 2019, 4:20 PM

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well physx will not be a package i dont think

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it's a dll

lapis plaza Mar 19, 2019, 4:20 PM

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physx is not really that great codebase to port tho

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it's barely human readable

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I mean, it's efficient, it's just not really nice to work with

tropic hamlet Mar 19, 2019, 4:20 PM

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thing is physx is actually battle tested and it does work really well

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hpc# is one man's go at stuff

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one guy

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hardly billions of dollars of research

lapis plaza Mar 19, 2019, 4:21 PM

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PhysX 4 is not battle tested tho

tropic hamlet Mar 19, 2019, 4:21 PM

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it doesn't need to be

lapis plaza Mar 19, 2019, 4:21 PM

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it does

tropic hamlet Mar 19, 2019, 4:21 PM

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4 is largely 3

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3.5x

lapis plaza Mar 19, 2019, 4:21 PM

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you clearly didn't use PhysX 3.4 when it was new

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it was a nightmare

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and yet it was improvement on 3.3

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not a new thing

tropic hamlet Mar 19, 2019, 4:21 PM

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i did actually

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I've been shipping games with physx since 2009

lapis plaza Mar 19, 2019, 4:22 PM

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I was the guinea pig for that on UE4, they got it integrated before it was publicly released

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and physx 4.0 isn't even released yet, it's still RC

tropic hamlet Mar 19, 2019, 4:22 PM

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and mostly on mobiles or contract

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so i know how to get them to be reasonable perf too

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(which makes them less stable...)

lapis plaza Mar 19, 2019, 4:22 PM

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just saying it's probably mostly fine but you will hit early adopter bugs without any doubt on it

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it just is bound to happen

tropic hamlet Mar 19, 2019, 4:23 PM

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need a fair bit of correction code and i think that... with physx moving to external it means that i lose all that engineering vs something totally brand new and barebones that requires me to code in ECS

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I'm not actually that upset

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the only problem is my character code (not controller, which is simple) is really quite heavily monobehaviour

lapis plaza Mar 19, 2019, 4:24 PM

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if nvidia ships the physx plugin sources, like even the native dll side

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then I can see that as on option

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as it does bring more to the table as the built-in Unity physx integration then

tropic hamlet Mar 19, 2019, 4:25 PM

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its a proper full-featured thing, wall jumping, combat, ai, dodging, etc, everything for a real complete character (and this is not the physics) but i would have to port to ecs or be given whatever physx has

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I get we can bridge it but... why would i bridge it

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unity's stated we can swap the backend

lapis plaza Mar 19, 2019, 4:35 PM

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oh man

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https://forum.unity.com/forums/physics-previews.123/

Unity Forum

Physics Previews

For feedback on experimental Physics previews.

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it's flooded with separate threads for the same thing now

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and the official thread isn't even in that forum section

tropic hamlet Mar 19, 2019, 4:50 PM

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what about cloth?

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I guess physx and havok will be in the lead feature wise for a long time

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the hpc# one is deterministic

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so that's a big deal

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@olento joe has replied

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it does see promising that Unity maybe taking their own physics engine seriously

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So far I saw an exploding deltatime demo so my concerns were a bit...

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+no clotho or spring stuff?

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( dont need )

lapis plaza Mar 19, 2019, 5:03 PM

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yeah, I noticed 😃

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I tried to get a straight answer, wasn't dissappointed

tropic hamlet Mar 19, 2019, 5:04 PM

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I'm happy he is on the ball (bad pun?)

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📎 unknown.png

jagged shale Mar 19, 2019, 5:27 PM

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we already confirmed that

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but I guess Hippo didn't believe us 😛

tropic hamlet Mar 19, 2019, 5:28 PM

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never believe this hive of scum and villiany

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I've learned that wishes aren't reality

lapis plaza Mar 19, 2019, 5:29 PM

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we got Havok guy on the physics thread now

tropic hamlet Mar 19, 2019, 5:47 PM

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huge lack of information and docs atm

lapis plaza Mar 19, 2019, 5:48 PM

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they actually have some docs on the package

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talking of which, what tools there are for windows to read markdown documents?

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would be nice to get proper formatting and navigation instead of just opening the files one by one in text editor

tropic hamlet Mar 19, 2019, 5:55 PM

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for md, I went through that looking for a markdown processor but only found crappy ones

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in the past

lapis plaza Mar 19, 2019, 5:56 PM

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yeah, I tried to find some myself before but didn't find anything good either

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So far we have used Box and Sphere for the collision types. Currently six distinct shapes are supported (and then *compound*, so multiple of these in one body, to allow more complex arrangements). Here they are in rough order of how expensive they are to use, from fastest to slowest:

* **Sphere** : a point with radius, so the simplest form of collision shape.
* **Capsule** : a line with radius, so a little bit more expensive than a sphere.
* **Plane** : a plane bounded four sides, so like a quad in graphics, but all 4 corner vertices are coplanar.
* **Box** : an oriented box. 
* **Cylinder** : currently this is actually a convex hull so will have the same cost as a similar complexity hull, so see next.
* **Convex Hull** : a 'convex hull' is as if you wrapped the object in paper, all the holes and concave parts will not be represented, just the outer most features. Collision detection algorithms for something you know is convex is much faster than concave.```

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so they might make proper cylinder primitive

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* **Mesh** : a arbitrary triangle soup. The most expensive and is assumed to be concave. All the convex shapes above all can collide with each other, and they can collide with Mesh, but Mesh can't collide with other Mesh in Unity Physics. So best used for static objects, but if you know your dynamic object Mesh will not need to collide with other Mesh it can be dynamic, but make sure to setup your collision filtering appropriately.

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it's nice that they allow that latter case

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in Unity 5+ they just hardcoded non-convex mesh collisions to static only

tropic hamlet Mar 19, 2019, 6:01 PM

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well unity's dots physics will basically use the same formulas as havok

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so it will just lack some of the more hardcore things havok can achieve

jagged shale Mar 19, 2019, 6:01 PM

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I wonder why they chose Havok over PhysX

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is it because of the networking aspect?

tropic hamlet Mar 19, 2019, 6:02 PM

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yeah likely

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but also havok had a lot of math and tech that's also under patents

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this industry is really big on having the right to use a technique

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so it's probably partially related

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only guessing ofc

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remember havok is only deterministic across the same CPU while dots physics aims to be deterministic no matter what CPU you are using. So unity's will end up better than havok for networking.

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(once burst updates to it)

lapis plaza Mar 19, 2019, 6:04 PM

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or Unity just had better connections to microsoft than nvidia

tropic hamlet Mar 19, 2019, 6:04 PM

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nah

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unity knows EVERYONE

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physx offers nothing unity hasn't already got

lapis plaza Mar 19, 2019, 6:04 PM

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it doesn't mean they didn't ask nvidia

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we wouldn't know

tropic hamlet Mar 19, 2019, 6:04 PM

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but nvidia hasn't got anything they need or can use

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unity already clearly said that havok is like dots internally

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so the code techniques aligned

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the hpc# IS using havok

#

same formulas and techniques, and it's dots friendly...

lapis plaza Mar 19, 2019, 6:05 PM

#

well, it's not Havok still

#

and obviously they've adopted things to unity dots thing

tropic hamlet Mar 19, 2019, 6:06 PM

#

physx would need a complete rewrite and a rethink, while havok already did the thinking ecs style

royal hearth Mar 19, 2019, 6:06 PM

#

I think it's fault of Ugo Foscolo, but idk...

tropic hamlet Mar 19, 2019, 6:06 PM

#

havok already works like unity dots does

lapis plaza Mar 19, 2019, 6:06 PM

#

I dunno about that

tropic hamlet Mar 19, 2019, 6:06 PM

#

so it was a very good plan to strike a deal

lapis plaza Mar 19, 2019, 6:06 PM

#

it's all about how you do the integration

tropic hamlet Mar 19, 2019, 6:06 PM

#

unity said this olento.

#

its what unity said not me

lapis plaza Mar 19, 2019, 6:06 PM

#

you can make physx work for the dots api for most parts

#

and since havok was involved in development, of course the dots physics api favors havok's design now

#

physx has stateless solvers too despite what Joe wrote

#

it's just most don't use the immediate mode on it

#

it doesn't have any scene or cache

tropic hamlet Mar 19, 2019, 6:08 PM

#

so it would be slower

lapis plaza Mar 19, 2019, 6:08 PM

#

sure

#

all I'm saying, that it could work for the DOTS api

#

they clearly made some deal with Havok, hence the integration

tropic hamlet Mar 19, 2019, 6:10 PM

#

unity said that you could just swap between physx/dots/havok and it would just work. but this implies they will make the new api work the same as physx for monobehaviour platform. probably using abstracted wrapper

#

i think physx was a mistake in that forum post and they meant only dots or havok being interchangable

#

having no cache does mean it's deterministic, right?

#

I mean stateless lets you go back and (forth a bit)

#

but the havok one seems to have a cache somehow

#

(there's always a catch)

lapis plaza Mar 19, 2019, 6:14 PM

#

I think you've misinterpreted the physx part

#

physx will stay for gameobject physics

#

unity physics and havok will be swappable with minimal work

tropic hamlet Mar 19, 2019, 6:15 PM

#

yeah definately makes sense like that

#

i'm very concerned though that there is already a pain point:

go with dots physics for determinism with any cpu but slower
go with havok for determinism with same cpu but faster

#

Unity is understandably keen to avoid benchmark discussions

lapis plaza Mar 19, 2019, 6:16 PM

#

it's not necessarily even slower with unity physics

#

it would still depend on the gameplay

tropic hamlet Mar 19, 2019, 6:16 PM

#

Well the blog literally states it would be unfair on unity to compare atm = it's slower

lapis plaza Mar 19, 2019, 6:17 PM

#

comparing any wip thing is unfair IMO 😄

tropic hamlet Mar 19, 2019, 6:17 PM

#

"if you have a team that has experience with Havok Physics or your use-cases are pushing on complex and high-fidelity physics requirements, the caching system of Havok Physics can offer better stability and performance," according to Bowell.

#

both better stability and performance.

lapis plaza Mar 19, 2019, 6:17 PM

#

it's marketing speech

tropic hamlet Mar 19, 2019, 6:18 PM

#

📎 unknown.png

#

they also dodged my request in forum posts

#

they really dont want comparisons

lapis plaza Mar 19, 2019, 6:18 PM

#

you can't really put clear answer on the perf now vs future perf without doing extensive testing

maiden grove Mar 19, 2019, 6:18 PM

#

premature is probably a better word than "unfair" (sounds defensive)

lapis plaza Mar 19, 2019, 6:18 PM

#

yeah

#

exactly

tropic hamlet Mar 19, 2019, 6:19 PM

#

unfair = it's slower, not really expected to get much faster
premature = we plan faster

lapis plaza Mar 19, 2019, 6:19 PM

#

and even if you do extensive testing, it really matters who prepares the tests

tropic hamlet Mar 19, 2019, 6:20 PM

#

well lets try the classic boxes test :P

lapis plaza Mar 19, 2019, 6:20 PM

#

if you've followed the industry discussion around physics engines, things got bit heated between physx and bullet devs when physx dev made their own benchmarking tool 😄

tropic hamlet Mar 19, 2019, 6:20 PM

#

hehe yes

lapis plaza Mar 19, 2019, 6:20 PM

#

he didn't really setup it like bullet should have been setup for the test

tropic hamlet Mar 19, 2019, 6:20 PM

#

becuse of the "differences" but in reality all projects are slower on bullet.

lapis plaza Mar 19, 2019, 6:20 PM

#

and despite asking the source code, I don't think bullet dev got it so he could have fixed it

tropic hamlet Mar 19, 2019, 6:20 PM

#

it bullshit, mostly stuff is gonna be faster or slower and you do see immediate gains or not

lapis plaza Mar 19, 2019, 6:20 PM

#

yeah, I don't really doubt that, but the test wasn't really fair either

tropic hamlet Mar 19, 2019, 6:21 PM

#

when I used tokamak and ODE, I could see tokamak was way faster, right from the outset, but ODE was more capable

#

here, we have same capability

#

so i expect pretty much a win or not

#

seems this cache thing might be a big deal

lapis plaza Mar 19, 2019, 6:22 PM

#

if it's a big deal, people will make cache system for the Unity Physics

#

just wish they'd put it on github

tropic hamlet Mar 19, 2019, 6:23 PM

#

unity claims a cache for it would be bad for rollback

lapis plaza Mar 19, 2019, 6:23 PM

#

it would encourage custom forks

#

yeah, that's kinda the reason they don't have it

#

but not all games need the rollback

tropic hamlet Mar 19, 2019, 6:24 PM

#

quite true

#

I'm just wondering what kind of difference it would make, and why unity would avoid adding it

jagged shale Mar 19, 2019, 6:25 PM

#

avoid adding what

tropic hamlet Mar 19, 2019, 6:25 PM

#

yeah I looked on github and didn't find dots physics

#

(@ol)

#

@jagged shale avoiding adding a cache for their stateless physics engine

lapis plaza Mar 19, 2019, 6:26 PM

#

heh

#

this workaround

#

Hmm, I know we've turned on vsync in the project Quality settings as a quick workaround

#

for the too fast physics

tropic hamlet Mar 19, 2019, 6:26 PM

#

loooooooool

#

oh dear, some red faces there!

jagged shale Mar 19, 2019, 6:27 PM

#

if it had a cache, it wouldn't be stateless 😛

tropic hamlet Mar 19, 2019, 6:27 PM

#

havok is stateless + cache

#

probably like you can have a cake and eat it

jagged shale Mar 19, 2019, 6:27 PM

#

cache is separate though

tropic hamlet Mar 19, 2019, 6:27 PM

#

yep and unity don't plan on adding a separate cache

jagged shale Mar 19, 2019, 6:27 PM

#

I mean there's nothing to prevent you from doing your own caching

#

probably best anyway

lapis plaza Mar 19, 2019, 6:28 PM

#

I'm pretty certain that the cache is what breaks the rollback determinism on physx

jagged shale Mar 19, 2019, 6:28 PM

#

you can make sure it's done how you want

lapis plaza Mar 19, 2019, 6:28 PM

#

on the same computer that is

tropic hamlet Mar 19, 2019, 6:28 PM

#

nothing preventing me writing my own game engine but i do need to draw the line somewhere....

jagged shale Mar 19, 2019, 6:28 PM

#

lol

lapis plaza Mar 19, 2019, 6:28 PM

#

well, don't worry about things you don't necessarily need

#

if you don't do huge worlds or mass simulations, almost any physics engine will do

tropic hamlet Mar 19, 2019, 6:29 PM

#

turns his nose up

#

only the best for my shovelware

jagged shale Mar 19, 2019, 6:29 PM

#

it's not about needing it, it's about saying you have it 😛

#

"our game has cached determinism (but shhhh we dont' use it)

tropic hamlet Mar 19, 2019, 6:32 PM

#

it's like doing damage in games, its always more if you look good doing it

jagged shale Mar 19, 2019, 6:33 PM

#

yes, need to do fancy gun spins and backflips

tropic hamlet Mar 19, 2019, 6:34 PM

#

and have a completely different gender with a really nice butt or something... will sell more than cache will :P

lapis plaza Mar 19, 2019, 6:58 PM

#

this looks kinda fancy https://forum.unity.com/attachments/bounce-gif.391057/

tropic hamlet Mar 19, 2019, 7:06 PM

#

see the one on the side?

#

he said "fk this, i'm gone"

#

and jumped

tropic hamlet Mar 19, 2019, 9:22 PM

#

https://forum.unity.com/threads/unity-physics-discussion.646486/#post-4337146

Unity Forum

Unity Physics Discussion

Hi everyone,

With the Unity Physics integration now available we would like to use this thread as a means of getting feedback, requirements, and...

#

"Also, performance seems suspicious (stack of 300 cubes brings my framerate to its knees, even when not using FixedUpdate), but I'll blame the early experimental status of the package for that"

#

seems super early then :P

tropic hamlet Mar 19, 2019, 10:00 PM

#

I like how in the docs it's referred to as damping (which is correct) and not drag...

jagged shale Mar 19, 2019, 10:02 PM

#

what is

tropic hamlet Mar 19, 2019, 10:09 PM

#

rigidbody drag / damping

#

it's really just a damping formula over time, while drag would need air resistence and all that jazz

#

or water etc, you know

jagged shale Mar 19, 2019, 10:13 PM

#

true

odd bough Mar 20, 2019, 2:25 AM

#

Lool @lapis plaza the funny thing is, I noticed the movement after spawning cubes and noticing the pile was.... alive somehow 😂

#

It is amazing how stable the objects are when they meet a static object

#

Then on the flipside how volatile they are when just barely touching a dynamic body

jagged shale Mar 20, 2019, 2:29 AM

#

yeah it looks to be a bug

#

shouldn't behave that way

odd bough Mar 20, 2019, 2:29 AM

#

I'd hope not

#

I had an amazing idea of making an ECS hour glass, but.... that needs stability

mild oriole Mar 20, 2019, 2:52 AM

#

hello

tropic hamlet Mar 20, 2019, 3:29 AM

#

Honestly, if it doesn't perform the same as physx does throughout I'm not sure there is enough reason to use it - period.

#

Since mostly, I use physx cosmetically, I expect the sim to be different on different machines, so I really only need to sync the player stuff

#

i could use both shugs ?

hollow echo Mar 20, 2019, 3:42 AM

#

I imagine we'll see systems released on github by anyone with an interest in it

#

and that'll be cool

mild oriole Mar 20, 2019, 3:56 AM

#

hey?

hollow echo Mar 20, 2019, 4:00 AM

#

yes people can read your messages

mild oriole Mar 20, 2019, 4:02 AM

#

yay!

tropic hamlet Mar 20, 2019, 4:10 AM

#

I can't

tropic hamlet Mar 20, 2019, 4:34 AM

#

huh

#

I probably have zero choice but to use Unity's if I have any interest in origin shifting, and I kind of do because why not :P

viral solstice Mar 20, 2019, 5:43 AM

#

I am mostly using physics for cosmetic (unless you count general collision-detection), but if it were deterministic I would totally open that up to using it left, right and center and everywhere inbetween. And then network it to many players too.

So I hope they get the new Unity Physics performing well soon-ish, because that's nifty.

lapis plaza Mar 20, 2019, 11:07 AM

#


    The Havok Physics variant will certainly support stable stacking out of the box, however....
    A major part of the design philosophy of Unity Physics is to provide a simple core, while ensuring open access to the data following through the system. So while at present the stateless nature of the Unity Physics preview doesn't support the likes of stable stacking, welding or deactivation, there should be nothing in the way of users adding and sharing the likes of contact caching themselves.

#

well, that's alarming

#

having stable dynamic vs dynamic contacts is an essential thing

hollow echo Mar 20, 2019, 11:08 AM

#

having one item on top of another is a pretty common thing!?

pearl warren Mar 20, 2019, 11:41 AM

#

Please

#

Physics engines don't need dynamic interactions

#

🙄

lapis plaza Mar 20, 2019, 11:46 AM

#

I wonder if the original plan was to make Unity Physics a multiplayer solution only and then hope people who need more would just agree to pay to MS for Havok

pearl warren Mar 20, 2019, 11:46 AM

#

bring out your notebook

lapis plaza Mar 20, 2019, 11:46 AM

#

there's really no good reason why Unity Physics couldn't have caching as option if full Havok can with the same API

pearl warren Mar 20, 2019, 11:47 AM

#

20k per component licence 😃

#

probably the deal they made so they can use havoc stuff for free Olento

lapis plaza Mar 20, 2019, 11:47 AM

#

the stateless thing has been mentioned quite few times but full havok isn't stateless and they can use the same API

#

so, that does bring up a lot of questions

#

it does sound like there's some bigger plan in works that they don't want to tell us about

#

I wouldn't be surprised if the full Havok integration will be only there for AAA customers

#

as Unity clearly tries to go into that market segment

pearl warren Mar 20, 2019, 11:52 AM

#

yep

#

feels like that to me too

lapis plaza Mar 20, 2019, 12:05 PM

#

as long as stacking is not happening, we can forget any kind of destruction using this setup

#

as that will result in a lot of dynamic objects on top of other dynamic objects

#

and in addition, I don't really see why they couldn't handle like some time limited buffer for some states, it wouldn't prevent rollbacks or ruin determinism

pearl warren Mar 20, 2019, 12:07 PM

#

physics in our game for a lot of cases is destroying something

#

and its a bunch of parts for visuals only client side

#

without collision on players

#

that will be a mess/

lapis plaza Mar 20, 2019, 12:07 PM

#

technically, we could still deal destruction on different physics engine as it's usually only visual

#

but it's still annoying to have multiple physics implementations

pearl warren Mar 20, 2019, 12:08 PM

#

https://www.fsegames.eu/images/choppychop.mp4

▶ Play video

#

as example in our game

lapis plaza Mar 20, 2019, 12:09 PM

#

yeah, that would fail on this new package 😃

pearl warren Mar 20, 2019, 12:09 PM

#

and mind you this is a very basic thing a lot of people are doing.

lapis plaza Mar 20, 2019, 12:09 PM

#

yeah

#

also people don't care for determinism on such thing

#

would be nice to have some option "keep cache for these objects only"

#

altho I dunno if that's really feasible to implement

#

I do get where they are going with the stateless thing, they are trying to solve one hard problem in networking with it

#

that's really cool thing about it

#

anyway, it does seem like they just threw it out looking at the response, Unity has taken community feedback into account on DOTS stuff before too, so there's always hope they'll listen this time around as well 😃

celest widget Mar 20, 2019, 12:28 PM

#

i care for determinism :p

lapis plaza Mar 20, 2019, 12:34 PM

#

on destruction?

#

even if it's only your client that sees it?

#

technically the determinism should still be there for first trigger, it's the rewind and resimulation that gets messed up if you can't reset the cache to the earlier state

celest widget Mar 20, 2019, 12:40 PM

#

for anything that has even the slightest impact on the simulation

lapis plaza Mar 20, 2019, 1:09 PM

#

for multiplayer, it makes sense

#

also for physics puzzle games

#

after that, I don't really see use cases that would require it

tropic hamlet Mar 20, 2019, 4:05 PM

#

unity's physics are for not physics basically

#

basically perfect for games which don't have regular physics but need fantastic query performance

#

like colliders, character controllers, etc

#

don't expect it for simulation

#

it does come unde physics of course but I'm just saying for intensive sims its not the thing

#

if their ragdoll demo is unity physics then I would be brave enough to say unity physics are very usable

#

rememeber it's deterministic

#

that's a big plus

pearl warren Mar 20, 2019, 4:09 PM

#

basically it's only build for DOTS style playback and rewinding network state of players?

tropic hamlet Mar 20, 2019, 4:13 PM

#

no it's just super light exactly what they're saying. it's the sort of thing I use physx for

#

I use physx mostly for strong queries, colliders etc, and handle the movement myself

#

it can do great ragdools, char controllers etc, anything

#

it does seem though they've deliberately avoided implementing anything that would bring it near havok

#

in any case we have physx still

jagged shale Mar 20, 2019, 4:19 PM

#

but PhysX isn't in ECS

pearl warren Mar 20, 2019, 4:20 PM

#

It seems to me just that Every time Unity is promising amazing things in presentations and when they actually deliver it, it can only be described as "meh" at best.

jagged shale Mar 20, 2019, 4:20 PM

#

i don't agree with the guy that 'settling is easy'

#

do you know how long it took Havok to get it right lol

#

wasn't until Havok 4 or 5

#

so i guess what they are really saying is "just use Havok"

#

since it seems it will be the only really viable physics

#

somehow i don't think it will be free though

pearl warren Mar 20, 2019, 4:22 PM

#

They stay very silent about that

#

I suppose it's going to be expensive

#

Very

#

Expensive

#

I noticed that Google was also pushing Havoc in the presentation

#

Something is telling me that Havoc is about to go bankrupt and they made big deals around the industry to stay relevant

#

since we have Physx going open source

#

Bullet is there for a while and many other options

#

The chance that a game developer buys a Havoc licence is turning to be 0 lately

jagged shale Mar 20, 2019, 4:24 PM

#

well the only reason they haven't is that Microsoft bought them

pearl warren Mar 20, 2019, 4:24 PM

#

true

jagged shale Mar 20, 2019, 4:24 PM

#

Havok has been passed around so many times

pearl warren Mar 20, 2019, 4:25 PM

#

but you cannot stay unprofitable department forever

maiden grove Mar 20, 2019, 4:25 PM

#

the business unit still needs to turn a profit

#

yeah

jagged shale Mar 20, 2019, 4:25 PM

#

when people keep buying and selling a company you know it's a dog

pearl warren Mar 20, 2019, 4:25 PM

#

Havoc was very relevant

#

but still today?

maiden grove Mar 20, 2019, 4:25 PM

#

Havok is one of those pieces of middleware that everyone wants and needs but no one wants to pay what it costs to maintain

tropic hamlet Mar 20, 2019, 4:25 PM

#

nice soundbite but really, it's fine

#

it wouldn't be industry leader otherwise

#

I mean, AAA isn't stupid.

jagged shale Mar 20, 2019, 4:26 PM

#

it used to be the only game in town

tropic hamlet Mar 20, 2019, 4:26 PM

#

OLD havok was a chore to work with but they have polished in the last 20 years

jagged shale Mar 20, 2019, 4:26 PM

#

now companies use it because they already own it

#

not because it's the best

#

don't discount the profit motive

#

why spend money on a new solution when you already own something else hehe

#

so yeah lot of AAAs continue to use it because ti's legacy within their company

#

not because it's the best

tropic hamlet Mar 20, 2019, 4:27 PM

#

so use physx since it's legacy and works for you

jagged shale Mar 20, 2019, 4:27 PM

#

😛

#

if it was in ECS i would!

tropic hamlet Mar 20, 2019, 4:28 PM

#

you realise when games earn billions and cost 200m to make that the license cost of havok is the least of anyone's problems

#

its lint to them

jagged shale Mar 20, 2019, 4:28 PM

#

it's about productivity

#

their people already know it

#

their tool chain is already set up to use it

#

their pool of assets and animations were already made for it

#

it's more than just 'license fee'

tropic hamlet Mar 20, 2019, 4:29 PM

#

yes and if something improves productivty, AAA do all that on the side risk free. It's why AAA all have huge unity licenses but don't necessarily use them for production

jagged shale Mar 20, 2019, 4:29 PM

#

changing physics engines rarely increases productivity

#

quite the opposite heh

#

since it touches just about everything

tropic hamlet Mar 20, 2019, 4:29 PM

#

i'm betting havok is just more stable under load. Physx has always been fast but unstable

jagged shale Mar 20, 2019, 4:30 PM

#

look at Bethesda

tropic hamlet Mar 20, 2019, 4:30 PM

#

physx's job is also to do whatever nvidia says is best for their gpus

jagged shale Mar 20, 2019, 4:30 PM

#

there's a reason they stil use the old, moldy Gamebryo engine with Havok

#

for 15 years now

#

because changing = pain

tropic hamlet Mar 20, 2019, 4:30 PM

#

so havok has never changed since?

#

never improved?

#

sat still inside microsoft

jagged shale Mar 20, 2019, 4:31 PM

#

of course it's changed

tropic hamlet Mar 20, 2019, 4:31 PM

#

useless piece of shit havok! we hate you which is why we use you in all sony first party games

jagged shale Mar 20, 2019, 4:31 PM

#

but not to the extent rewriting all your tools for a new engine would entail

#

not to mention invalidating your asset library

#

also you assume every studio jumps on every upgrade

#

(spoiler: they don't)

tropic hamlet Mar 20, 2019, 4:32 PM

#

but the thing is here is that Sony does rewrite for first party games, it has to squeeze the most bang for buck because first party games are responsible for selling the console

jagged shale Mar 20, 2019, 4:32 PM

#

same way people will stick with Unity 5.6

#

when we have 2019 out

#

once their game is on a version, they aren't changing

tropic hamlet Mar 20, 2019, 4:32 PM

#

then we have a brand new engine by ubisoft for nintendo (the mario/rabbids crossover) which for switch, used havok. That's telling

#

I'm sure it's going to be on par with physx and all that but I doubt, strongly doubt its bad

jagged shale Mar 20, 2019, 4:33 PM

#

it's what their people like

#

people really hate change

tropic hamlet Mar 20, 2019, 4:34 PM

#

true but that doesn't mean it's not better

jagged shale Mar 20, 2019, 4:34 PM

#

doesn't mean it is either ;p

tropic hamlet Mar 20, 2019, 4:34 PM

#

I do think unity's builtin physics will not come close to physx though for non networked scenarios

#

rigidbodies etc

#

sim stuff

#

they said in docs for unity physics, they expect the perf to be same as leading physics engines for queries but not for sim

jagged shale Mar 20, 2019, 4:35 PM

#

physics will always be a hard problem to solve

tropic hamlet Mar 20, 2019, 4:35 PM

#

so your raycasts, shape casts, etc all should be top as expected... but not the simulation or stacking

#

physx probably remains fastest if you want it for visuals

#

i'm used to physx's quirks

jagged shale Mar 20, 2019, 4:37 PM

#

funny enough the tools I've worked with for the last 10 years have been havok based

#

so I know it's quirks

tropic hamlet Mar 20, 2019, 4:37 PM

#

physx is super temporal really

jagged shale Mar 20, 2019, 4:38 PM

#

i just want something in ECS that works reasonably well

#

and doesn't cost an arm and a leg

tropic hamlet Mar 20, 2019, 4:38 PM

#

we dont have to rush

jagged shale Mar 20, 2019, 4:38 PM

#

and so far neither option meets those criteria

#

now they could surprise me and say havok is free

#

but it's Microsoft

#

so I don't se that happening

#

but stranger things have happened i guess

tropic hamlet Mar 20, 2019, 4:40 PM

#

unity's havok integration is likely to be as pain free as physx, all nice ui etc

#

fancy slider bar

jagged shale Mar 20, 2019, 4:41 PM

#

yes I have all the Havok SDKs from when Intel used to offer them for free 😛

#

(which Microsoft put a swift end to)

#

I've lived long enough to know a good thing is temporary so archived them all heh

#

so I've got a lot of experience with how it works

#

honestly their tools were poor

#

coder art

#

but they got the job done

#

i wonder how much M$ has cleaned them up

tropic hamlet Mar 20, 2019, 4:45 PM

#

i dont know but i do know I have something I can use today: physx

jagged shale Mar 20, 2019, 4:45 PM

#

but not in ECS 😛

tropic hamlet Mar 20, 2019, 4:45 PM

#

very true

#

but I dont yet see a compelling reason to use ECS when:

unity will still render my world with ECS even if I don't use it
unity will still accelerate all their systems with ECS even if I don't use it

... so I might not use it :)

maiden grove Mar 20, 2019, 4:46 PM

#

Whats the rationale for providing Unity Physics (and not just Physx OR Havok) to begin with?

#

like why 3 lanes?

tropic hamlet Mar 20, 2019, 4:47 PM

#

because ceebee hogs the middle lane, I get caught in the bus lane and those in the fast lane do not see the cliff

maiden grove Mar 20, 2019, 4:47 PM

#

haha

#

The type of game to lean into DOTS and want a deterministic high perf physics engine is likely to be the game of game to pay the licensing fee

jagged shale Mar 20, 2019, 4:48 PM

#

i think they got tired of people asking for deterministic physics for networking

#

and it's true Havok is probably one of the few players who has that

#

as in, the ability to rewind for syncing clients

#

and by tying that to ECS they can push people to use ECS

maiden grove Mar 20, 2019, 4:49 PM

#

I guess Unity Physics is a wrapper and a hedge against Havok? Like eventually they see themselves replacing some of those bits?

jagged shale Mar 20, 2019, 4:50 PM

#

it's the weak alternative so people can't say they have no alternatives lol

maiden grove Mar 20, 2019, 4:50 PM

#

yeah

tropic hamlet Mar 20, 2019, 4:50 PM

#

my hot take on it:

physx cannot be made into ECS, it's just too different for dots
unity looked around for something deterministic with same dots style code, only havok had that
unity's own efforts fell so far short that they quickly realised that all the physics coders they wanted were hired, and all the techniques they wanted were patented
so they struck a deal: they get the core patented algos for the basics from havok for the new Unity Physics (dots physics) and in return, havok gets partner intergration

that's my hot take on it, not what Unity has said happened.

jagged shale Mar 20, 2019, 4:51 PM

#

i'll even bet that's part of their agreement with Microsoft: "You can't make a competing physics alternative"

tropic hamlet Mar 20, 2019, 4:51 PM

#

yes correct

#

because the techniques used in unity physics are the same ones as in havok

#

read the docs it even SAYS so

jagged shale Mar 20, 2019, 4:52 PM

#

well all physics engines mostly use the same techniques

tropic hamlet Mar 20, 2019, 4:52 PM

#

not patented ones

jagged shale Mar 20, 2019, 4:52 PM

#

there's only so many ways to skin a cat

tropic hamlet Mar 20, 2019, 4:52 PM

#

havok has a battery of patents.

jagged shale Mar 20, 2019, 4:52 PM

#

sure, i know

#

but clearly there are other ways, or bullet and PhysX wouldn't exist

tropic hamlet Mar 20, 2019, 4:53 PM

#

its just maths in the end

#

sure and physx resists determinism and bullet is dog slow

jagged shale Mar 20, 2019, 4:53 PM

#

hehe

tropic hamlet Mar 20, 2019, 4:53 PM

#

if unity want hardcore ecs physics over the network it doesn't make sense to fail for 10 years to follow physx and bullet

jagged shale Mar 20, 2019, 4:53 PM

#

nobody is perfect 😛

tropic hamlet Mar 20, 2019, 4:54 PM

#

i hate to say it but imho unity made the right call

jagged shale Mar 20, 2019, 4:54 PM

#

yes unity isn't in the physics engine business

tropic hamlet Mar 20, 2019, 4:54 PM

#

you only make what you can't buy

#

i don't believe I need to care about the physics engine in use if unity will wrap it up nice

#

i just care about what i can do

#

i am not even slightly pleased with dots physics performance at the moment

#

so unity will still have to try much harder

#

(don't think because I think unity did the right thing, that I like what they did)

jagged shale Mar 20, 2019, 4:57 PM

#

finally something we can agree on 😛

tropic hamlet Mar 20, 2019, 4:57 PM

#

stranger things happen :P

maiden grove Mar 20, 2019, 4:57 PM

#

i don't believe I need to care about the physics engine in use if unity will wrap it up nice
Unity abstractions never leak, right?

tropic hamlet Mar 20, 2019, 4:58 PM

#

not sure what you mean

maiden grove Mar 20, 2019, 4:58 PM

#

just that it'll never been as clean as "just switch out the backend" :p

tropic hamlet Mar 20, 2019, 4:58 PM

#

you mean have allocations? unity is removing all that over time

maiden grove Mar 20, 2019, 4:58 PM

#

sorry, leak as in - https://en.wikipedia.org/wiki/Leaky_abstraction

Leaky abstraction

In software development, a leaky abstraction is an abstraction that leaks details that it is supposed to abstract away.

tropic hamlet Mar 20, 2019, 4:59 PM

#

ah I see

maiden grove Mar 20, 2019, 4:59 PM

#

just snark

tropic hamlet Mar 20, 2019, 4:59 PM

#

yes yant has been talking about that

#

he's been talking about how the physics engine shouldn't really offer anything it doesn't do itself in the unity front end

#

trigger to trigger stuff is one thing like that

#

i agree with you :D

jagged shale Mar 20, 2019, 5:00 PM

#

well that's a PhysX problem

#

they USED to support it

tropic hamlet Mar 20, 2019, 5:00 PM

#

i guess thats telling through, they can switch between dots physics and havok without leaky abstraction but physx will never be part of that party

jagged shale Mar 20, 2019, 5:00 PM

#

and then removed it

#

it's not like Unity set out from the start to offer something PhysX didn't

tropic hamlet Mar 20, 2019, 5:04 PM

#

I do think the unity builtin (free) new option needs stronger perf though. hope it's coming.

#

i love that it's open and i can make it my own

#

dont love it not as fast :P

jagged shale Mar 20, 2019, 5:05 PM

#

well i just care about it being basically functional

tropic hamlet Mar 20, 2019, 5:05 PM

#

whole point of ECS was "it's earth shatteringly great and bestest of all perf" so why is it not?

jagged shale Mar 20, 2019, 5:05 PM

#

and if you can't rest one dynamic object on another, it's not functional

#

try having your character stand on a moving platform LOL

#

or anything else basic

tropic hamlet Mar 20, 2019, 5:06 PM

#

for me its broken for as long as I can't stack 3 cubes. Really the minimum stacking is 3, wouldn't you agree?

#

2 is a fluke

#

3 is... hardcore

jagged shale Mar 20, 2019, 5:06 PM

#

havok just basically checks for movement for a period you set

#

once that threshold is reached it 'sleeps' the physics on the object

#

(not patentable :P)

tropic hamlet Mar 20, 2019, 5:07 PM

#

📎 unknown.png

#

not an acceptable feature.

jagged shale Mar 20, 2019, 5:08 PM

#

yeah i already saw that

#

and dubbed it 'bullcrap'

tropic hamlet Mar 20, 2019, 5:08 PM

#

stacking is required, but we don't need to go nuts, just enough to put books on a bookshelf, surely? for common game scenarios

#

https://forum.unity.com/threads/unity-physics-discussion.646486/page-2

Unity Forum

Unity Physics Discussion

I'm actually trying to create a quick networked test that shows server authoritative movement with client-side prediction. Since this physics engine is...

#

my hateful reply at the bottom

#

(it's constructive but hate sounds better)

jagged shale Mar 20, 2019, 5:16 PM

#

Edy - the builtin integration of PhysX isn't going to disappear any time soon, we will maintain, support and improve it for a while. That said, we still target at shipping PhysX 4.x upgrades once they're ready.

#

wonder how long 'for awhile' is

lapis plaza Mar 20, 2019, 5:16 PM

#

sounds like they don't know themselves either what is going to happen

jagged shale Mar 20, 2019, 5:18 PM

#

https://forum.unity.com/threads/physx-4-0-in-unity-experimental-builds.634960/#post-4338958

Unity Forum

PhysX 4.0 in Unity - experimental builds

Hi everyone,

(this post will be edited to reflect the latest changes)

We're aiming at updating our PhysX version to 4.0 this year. PhysX 4 was...

#

also the latest here

#

his saying how "wonderful" DOTS physis is aggravated me

maiden grove Mar 20, 2019, 5:19 PM

#

haha

#

Can I parrot your guys analysis back to you so I can bring it back to my team and sound smart?

1.) Physx - This is for games that are not using ECS and don’t require a deterministic physics simulation. Generally Physx will be faster with simulation than other options
2.) Unity Physics - This is for games that are leveraging ECS and require determinism and rollbacks. Aim here is for queries to be on par with Physx, but no guarantees on simulation speed.
3.) Havok Physics - This is for games that are leveraging ECS and require determinism and rollbacks and performance (as well as the stability and maturity of Havok). Both queries and simulation will likely be on par with Physx.

#

These are the 3 lanes that are going to be available starting 2019+

jagged shale Mar 20, 2019, 5:20 PM

#

honestly I don't even know that "Unity Physics" supports determinisim and rollbacks.

#

it seems so super basic

maiden grove Mar 20, 2019, 5:20 PM

#

it says it on the box

jagged shale Mar 20, 2019, 5:20 PM

#

ok if it says so...

maiden grove Mar 20, 2019, 5:20 PM

#

😄

#

of these, #2 seems like it may just become "the wrapper" over #3

jagged shale Mar 20, 2019, 5:21 PM

#

also i read the performance isn't on par with PhysX

#

someone said they tried having 300 boxes moving and it brought editor to a crawl

#

which is BAD peformance

#

but it is basically alpha

#

so hopefully that aspect improves

#

https://forum.unity.com/threads/unity-physics-discussion.646486/#post-4337146

Unity Forum

Unity Physics Discussion

Hi everyone,

With the Unity Physics integration now available we would like to use this thread as a means of getting feedback, requirements, and...

#

yeah was hippo that linked to that post

#

Also, performance seems suspicious (stack of 300 cubes brings my framerate to its knees, even when not using FixedUpdate), but I'll blame the early experimental status of the package for that

pearl warren Mar 20, 2019, 5:28 PM

#

I can confirm the bad perf myself

#

hard to compare with build in physx but it looks like 100x times as slow.

tropic hamlet Mar 20, 2019, 5:32 PM

#

well built in physx in my scenes has 0.5ms or so for a huge pile of cubes

#

(with stable stacking)

#

another bonus dots physics has:

#

free origin shifting since it's stateless

#

its 100% free to just shift

#

whikle there is a huge cost with cached systems

#

with stateless you just move it, like it's being moved anyway per frame, so the movement is free

lapis plaza Mar 20, 2019, 5:38 PM

#

you could handle the large world support many ways on ECS

#

like, keep the main transforms in doubles but shift them for both rendering and physics solving so those would get to use faster floats

#

unless you really need to solve the physics on the whole world at once

#

but I'm now thinking some open world/universe thing where player is only at the one part of the world at once

#

I'd love to get proper AVX support for doubles on Burst

#

but I doubt it's happening, unless LLVM somehow does that automatically under the hood

#

right now Burst is hardcoded to SSE4 on windows anyway

#

that's also something I'd want Unity to improve with

#

like, detect the clients CPU and pick the extension for it accordingly

#

today we still have people running those ancient phenoms etc that don't have SSE4 even

#

and AVX is still only like 85% of the computers

jagged shale Mar 20, 2019, 5:43 PM

#

heck many programs are only now adding SSE2

#

since people have stuff older than that

lapis plaza Mar 20, 2019, 5:44 PM

#

tbh, I don't really care that much for those phenom owners today

#

those cpu's are so old they could barely run games launched today anyway

#

and that's like 4% of the playerbase according to steam stats that don't have SSE4.1

#

AVX is different tho

#

Intel still makes CPUs that don't have AVX support

#

it's kinda stupid thing

#

I mean, most chips have the support

#

but they still do the budget things that don't

jagged shale Mar 20, 2019, 5:49 PM

#

yeah it's true

#

https://i.imgur.com/HWqYxDR.png

Imgur

#

my processor has all the candy

pearl warren Mar 20, 2019, 5:51 PM

#

I am out of my topic here but does it sound very stupid to suggest shoulden't a runtime use certain instruction sets dynamically on platform?

lapis plaza Mar 20, 2019, 5:58 PM

#

UE4's new physics engine got caching 😄

#

I know, lame joke

#

📎 unknown.png

#

their fracturing stuff = nvidia blast

jagged shale Mar 20, 2019, 6:00 PM

#

neato

#

but Unreal stuff probably belongs in off-topic 😛

lapis plaza Mar 20, 2019, 6:08 PM

#

unreal is streaming this live now

#

they have option to pre-bake the simulation but then let dynamic things activate their dynamic sim for the parts they hit

#

it's pretty cool setup

jagged shale Mar 20, 2019, 6:10 PM

#

yeah sounds like how Blender does dynamics

#

you bake the sim and then can replay it from the cache

lapis plaza Mar 20, 2019, 6:14 PM

#

yeah, but this lets you interact with the cache

#

it becomes live at that point

#

but yeah, this is so far for demolition, while cool, I'm not that impressed unless they can use this stuff to improve actual physics sim in ue4

#

ue4 hasn't really been great on that front

#

📎 unknown.png

#

so....

#

everyone is dumping physx? 😄

pearl warren Mar 20, 2019, 6:21 PM

#

The question is why

lapis plaza Mar 20, 2019, 6:21 PM

#

it's a good question

blissful shore Mar 20, 2019, 7:45 PM

#

all game engines will inevitably have their own physics and math libraries

this is inevitable

jagged shale Mar 20, 2019, 7:46 PM

#

now that PhysX is open source they can steal all it's secrets 😛

#

oh i mean, 'learn from it and make their own'

lapis plaza Mar 20, 2019, 7:52 PM

#

well, UE already had custom physics engine

#

around the UE2 days

#

but they moved to third party offerings

jagged shale Mar 20, 2019, 7:55 PM

#

yeah back then it was the wild west

#

there were no 3rd party anything, everyone rolled their own everything

#

middleware was something that came out of maturation of the industry

#

but as things have consolidated, it does make more sense for things to coalesce into monolithic systems once again.

pastel dawn Mar 20, 2019, 10:37 PM

#

So, I've remade the Open Character Controller script for fun (https://github.com/Unity-Technologies/Standard-Assets-Characters/blob/master/Assets/_Standard Assets/Characters/Scripts/Physics/OpenCharacterController.cs) into the new unity physics! (and that can be jobified!).
Right now, there are some issues that are still need to be fixed that are visible on the video (as it was just a fast 1:1 conversion for fun) and I didn't added the sliding on slopes (the one that is called at update)
https://streamable.com/r2ij6

I'll upload the script once I'll clean it a bit^^

Streamable

2019-03-20 23-33-15 - Streamable

▶ Play video

lapis plaza Mar 20, 2019, 10:39 PM

#

@pastel dawn that's cool, did it take long to port?

pastel dawn Mar 20, 2019, 10:39 PM

#

it almost took the entire day x)

covert vale Mar 20, 2019, 10:39 PM

#

gosh damn thats awesome

#

like 1000x better then what I can create

lapis plaza Mar 20, 2019, 10:39 PM

#

now only need to port the new char controller to ECS too 😄

pastel dawn Mar 20, 2019, 10:40 PM

#

@lapis plaza isn't the OCC the new char controller?

lapis plaza Mar 20, 2019, 10:40 PM

#

it is

#

I'm talking about the same thing

#

it's not using ECS

pastel dawn Mar 20, 2019, 10:40 PM

#

but, I've (almost) made it to work with ECS 🤔

#

the character component is a struct component

lapis plaza Mar 20, 2019, 10:41 PM

#

oh, I thought you did gameobject port

pastel dawn Mar 20, 2019, 10:41 PM

#

ah no^^

lapis plaza Mar 20, 2019, 10:41 PM

#

way ahead of my thinking then 😄

pastel dawn Mar 20, 2019, 10:42 PM

#

well, I'll put the code tomorrow on github if you are interested! (well... I originally planned to put it...)

tropic hamlet Mar 20, 2019, 11:25 PM

#

it's necessary for gaming world of multiplayer and content streaming that has lightweight origin shifting to exist, and this has never been AAA's problem, but for the masses, you can't use physx and keep costs down. you just can't do it.

#

without determinism it'll cost you too much money

#

and you'll be priced out like you've always been

#

which is why you've never had it before

#

https://www.photonengine.com/quantum etc

Blazing Fast Deterministic Networking Engine | Photon Engine

The revolution in multiplayer games development! Create MOBAs, brawler, RTS, fighting and sports games with the blazing fast deterministic networking engine: QUANTUM.

#

combining physics and networking is mandatory tbh

#

or at least have them play together

#

physx plays with no-one

jagged shale Mar 20, 2019, 11:26 PM

#

yes this is known

tropic hamlet Mar 20, 2019, 11:26 PM

#

its good in single player and you can get it to do mp no problem

#

but it will cost you much more money than deterministic ones would

jagged shale Mar 20, 2019, 11:27 PM

#

but for those of us who wouldn't touch networking with a 20 foot pole, it doesn't matter 😛

tropic hamlet Mar 20, 2019, 11:27 PM

#

and latency is still not fixed.

#

yeah but

#

this also makes networking a u t o

#

you send inputs

#

done

jagged shale Mar 20, 2019, 11:27 PM

#

my unity friend whined about having the ability to rewind daiily

tropic hamlet Mar 20, 2019, 11:27 PM

#

its perfect for unwashed masses like me.

#

i am very much an unwashed mass.

#

nothing prevents me keeping physx around for some effects work

blissful shore Mar 20, 2019, 11:32 PM

#

downsides:
Stacking doesn't work yet, maybe we get an in-house solution

upsides:
Time travel possible without 1.21 Jigawatts

tropic hamlet Mar 20, 2019, 11:32 PM

#

heart for ref

#

And regarding stacking, I guess I would find ways around it to make it work, I would have to.

tropic hamlet Mar 21, 2019, 12:08 AM

#

so

#

looks like there will never be a builtin destruction library in unity so we shoud look at maybe how that would work

#

I mean, it's 100% clear now where Unity's spending the time and it will not be for destruction physics. Not a big deal but the competition has gone there

jagged shale Mar 21, 2019, 12:10 AM

#

destruction has never been hard

tropic hamlet Mar 21, 2019, 12:10 AM

#

so part of the main problem is authoring

jagged shale Mar 21, 2019, 12:10 AM

#

it's just making it performant

tropic hamlet Mar 21, 2019, 12:10 AM

#

the physics side not an issue

jagged shale Mar 21, 2019, 12:10 AM

#

no, just the opposite

#

authoring is easy

#

it's the physics that make it laggy to do

tropic hamlet Mar 21, 2019, 12:11 AM

#

at runtime in unity, say you want to destroy a cube? this is simple, you break it using DCC tools, import the broken version and instantiate it, right?

jagged shale Mar 21, 2019, 12:11 AM

#

i'll say yes though I don't know what "DCC tools" is

tropic hamlet Mar 21, 2019, 12:11 AM

#

the instantiation cost can be easily absorbed with ECS - with ecs, creating 100 objects in 1 frame is in fact as close to "free" as you can get.

jagged shale Mar 21, 2019, 12:11 AM

#

I'd use blender's fracture

blissful shore Mar 21, 2019, 12:11 AM

#

Maya, blender etc are DCC tools

hollow echo Mar 21, 2019, 12:11 AM

#

digital content creation

jagged shale Mar 21, 2019, 12:12 AM

#

I call them Mesh Editors

#

MEs 😛

tropic hamlet Mar 21, 2019, 12:12 AM

#

I call them Ceebee objections (CBO)

jagged shale Mar 21, 2019, 12:12 AM

#

but anyway, sure you use your favorite tool

tropic hamlet Mar 21, 2019, 12:12 AM

#

I am using myself

#

being a tool and all

#

but lets continue

jagged shale Mar 21, 2019, 12:12 AM

#

but then you instantiate several hundred items, all physical

#

and your game tanks

#

not to mention all the particles etc

tropic hamlet Mar 21, 2019, 12:13 AM

#

yes so that means really, runtime authoring of the destruction is needed in part at least

#

I mean the storage becomes insane

jagged shale Mar 21, 2019, 12:13 AM

#

there's systems to do the 'cutting up' at runtime as well

#

I have a pretty good one

#

but it's the same thing

tropic hamlet Mar 21, 2019, 12:13 AM

#

otherwise i guess you will always split the cube into 100 pieces even though only half was broken off.

jagged shale Mar 21, 2019, 12:14 AM

#

now you're doing that work AND the physics at runtime

#

so really it's worse

#

there's a really aweome talk by Ubisoft

tropic hamlet Mar 21, 2019, 12:14 AM

#

we've got destruction in our game, but it's really primitive, for example an urn will use the same broken bits as anything similar to it, the broken bits are more generic than it seems. that was my solution at least, so no bespoke creation or partial destruction: it's either broken bits or it's not.

jagged shale Mar 21, 2019, 12:15 AM

#

about their procedural destruction system for Rainbow 6 Siege

#

and they have all the same issues, but They literally did something kind of like ECS

#

also they make debris vanish very fast

#

kind of cartoony

#

https://www.gdcvault.com/play/1023003/The-Art-of-Destruction-in

The Art of Destruction in 'Rainbow Six: Siege'

Introducing a game-changing technology in a AAA game comes with its own set of challenges. It's not enough to develop a new technology, you need to make it play nicely with other systems in the game. This session is about developing and...

tropic hamlet Mar 21, 2019, 12:16 AM

#

I would probably let particles do most of the job

jagged shale Mar 21, 2019, 12:16 AM

#

here it is

#

it's an interesting read

#

they customize the physics to make their style of destruction more robust

#

but this here is the key thing about debris

#

https://i.imgur.com/wXzcClo.png

Imgur

#

they do not just cut things up

tropic hamlet Mar 21, 2019, 12:19 AM

#

wtf

jagged shale Mar 21, 2019, 12:19 AM

#

they make replacement chaff

#

and just throw it around

tropic hamlet Mar 21, 2019, 12:20 AM

#

I do that too! i though it was just me being a primitive twit

jagged shale Mar 21, 2019, 12:20 AM

#

and it disappears fairly quickly

#

nah it's really the best thing to do

tropic hamlet Mar 21, 2019, 12:20 AM

#

i guess one needs to be a primitive twit for perf

jagged shale Mar 21, 2019, 12:20 AM

#

using mesh particle systems is ideal for this

tropic hamlet Mar 21, 2019, 12:20 AM

#

although the authoring here is still done art side, no special tooling,. i just find the nearest matching debris and use it

#

so partial destruction has same cost as full unfortunately in my case

#

its fixable with a trick - sorta

#

using static batching

#

because with static batching, you can hide elements of your choice but the rest will still be robustly batched

#

this is one of the reasons why static batching is a mem hog

#

but then doing this, we find it's really a local HLOD

#

too much work for me i think

jagged shale Mar 21, 2019, 12:23 AM

#

HLOD?

#

(if it's not become apparent, I really hate abbreviations and those lettery things people use instead of whole names)

tropic hamlet Mar 21, 2019, 12:23 AM

#

hierarchical lod, where the bits are separate close up but swapped for combined lower poly ver

jagged shale Mar 21, 2019, 12:24 AM

#

Acronym

tropic hamlet Mar 21, 2019, 12:25 AM

#

HLOD is something everyone is expected to know about because it's a big thing with DOTS based rendering.

Hierarchical Level of Detail is something everyone is expected to know about because it's a big thing with Data Oriented Tech Stack based rendering, and now my hands are tired.

jagged shale Mar 21, 2019, 12:25 AM

#

oh I know about it, I just don't know the short name

#

HLOD could be literally anything

#

Happy Logs Out Drinking

tropic hamlet Mar 21, 2019, 12:26 AM

#

a few open world games use it, I noticed it was in the gta 5 breakdown

jagged shale Mar 21, 2019, 12:26 AM

#

Half-time Longcat Overdosing on Drugs

tropic hamlet Mar 21, 2019, 12:26 AM

#

it's in the megacity demo project in the toolbar as well

#

under HLOD

#

brb shouting at unity's staff for daring to abbreviate

jagged shale Mar 21, 2019, 12:26 AM

#

hehe

tropic hamlet Mar 21, 2019, 12:27 AM

#

nah I get ya

hollow echo Mar 21, 2019, 12:27 AM

#

these acronyms are all easily googlable though 🤷

jagged shale Mar 21, 2019, 12:27 AM

#

all LOD is hierarchial.

#

so it's kind of redundant

hollow echo Mar 21, 2019, 12:27 AM

#

no it's not

jagged shale Mar 21, 2019, 12:27 AM

#

yes it is

#

check out the LOD component sometime

tropic hamlet Mar 21, 2019, 12:27 AM

#

I think they mean lots of separate bits become fewer but lower poly bits in this case

jagged shale Mar 21, 2019, 12:27 AM

#

there's a hierarchy from LOD 0 to LOD 3

#

or however many LOD levels you make

hollow echo Mar 21, 2019, 12:28 AM

#

that's not used as a hierarchy though

jagged shale Mar 21, 2019, 12:28 AM

#

and they display one at a time based on distances you set

hollow echo Mar 21, 2019, 12:28 AM

#

and not what the word hierarchical means

jagged shale Mar 21, 2019, 12:28 AM

#

if they were flat, they would all display at once

#

so they are Hierarchial

hollow echo Mar 21, 2019, 12:28 AM

#

sure if you want to be oblivious

jagged shale Mar 21, 2019, 12:29 AM

#

Look I know you have some kind of problem with me

#

i don't know exactly what, maybe I threaten you

tropic hamlet Mar 21, 2019, 12:29 AM

#

(fyi I like you ceebee, I have never had a problem with you if you mean me)

jagged shale Mar 21, 2019, 12:29 AM

#

But the snarky bullshit is getting old

hollow echo Mar 21, 2019, 12:29 AM

#

what?

jagged shale Mar 21, 2019, 12:29 AM

#

you hover around everything I say

#

trying to find some tiny thing to harp on

hollow echo Mar 21, 2019, 12:30 AM

#

we're both on the discord all day man

jagged shale Mar 21, 2019, 12:30 AM

#

and I really don't appreciate it

tropic hamlet Mar 21, 2019, 12:30 AM

#

slowly backs out of the room

jagged shale Mar 21, 2019, 12:30 AM

#

I don't play that game but I can start

tropic hamlet Mar 21, 2019, 12:30 AM

#

I'll say this tho ceebee, I like you and if my occasional teasing is too much then np I will stop

#

clearly you've got the wrong end of the stick.

hollow echo Mar 21, 2019, 12:31 AM

#

I've got no beef either O.o

jagged shale Mar 21, 2019, 12:31 AM

#

hi·er·ar·chy
/ˈhī(ə)ˌrärkē/
noun
noun: hierarchy; plural noun: hierarchies
a system or organization in which people or groups are ranked one above the other according to status or authority.

#

LOD 0 is above LOD 1

#

LOD 1 is above LOD 2

#

it's a Hierarchy

tropic hamlet Mar 21, 2019, 12:32 AM

#

True yeah I agree, anyway I think in the case of the HLOD I guess they mean an additional hierarchy to that, sort of like an octree of lods?

#

(you are 100% correct ofc)

hollow echo Mar 21, 2019, 12:33 AM

#

I agree, I'm sorry - I mean to say that a linear hierarchy is already defined in the word LOD, I assumed you were talking about their existence in the Hierarchy

tropic hamlet Mar 21, 2019, 12:33 AM

#

the hierarchy of classic lod is 3..2..1...0 but here we have 0..1..2.. gone! (and spawn a fused lower poly bigger one)

#

saves draw calls i guess

jagged shale Mar 21, 2019, 12:33 AM

#

yes I get the new LOD stuff is further branched out

#

but simply from their descriptions

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I really haven't had time to examine it in depth

tropic hamlet Mar 21, 2019, 12:34 AM

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I actually thought it was bad in classic unity to have a lot of lods because each lod in the classic way, meant a different unbatchable object if that makes sense?

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so 5 lods in an open world for a lot of things would reduce poly count a lot but it would be way higher potential setpass

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the SRP batcher arnaud did at unity aims to fix all that too!

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you heard of it?

jagged shale Mar 21, 2019, 12:35 AM

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yes i heard about the batcher

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and I agree, LODs can sometimes be more harm than good

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I've actually heard the LOD system is not very performant in Unity

tropic hamlet Mar 21, 2019, 12:36 AM

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tbh when I heard of it... I thought it was absolute magic, i mean ACTUAL magic... because you no longer care about if one material is different to another...it batches by SHADER instead! mad right?

jagged shale Mar 21, 2019, 12:36 AM

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but it's' probably best to use it if you'll get huge triangle count savings

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but not if it's minor

tropic hamlet Mar 21, 2019, 12:36 AM

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true

jagged shale Mar 21, 2019, 12:37 AM

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and you should definitely author so every LOD uses the same textures

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i.e. material so you don't run into issues with having a lot of extra materials

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sometimes you can't do that

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but a lot of times you can

tropic hamlet Mar 21, 2019, 12:38 AM

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SRP batcher means I suppose, less worry about if the lod needed a different material, so long as its the regular shader

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is it something working on builtin?

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i mean could they port it?

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seems to me it would solve a huge part of buitin's problems and ... why not?

jagged shale Mar 21, 2019, 12:39 AM

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i don't know, i have a feeling they won't be doing anything to improve the legacy pipeline

hollow echo Mar 21, 2019, 12:40 AM

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I do wonder about the future of it

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and whether they'll depreciate it entirely

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at least in the nearish term

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years not decades 😛

jagged shale Mar 21, 2019, 12:41 AM

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it may not be for a few years, but i'm sure once the SRPs are stable, they will

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i'd love to get a look at Call of Duty's Custom SRP

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i wonder how different it is from LWRP/HDRP

hollow echo Mar 21, 2019, 12:47 AM

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is HLOD in megacity implicitly built into the structure of the prefab hierarchy?

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Or is there manual setup somewhere

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Ah there's an HLOD component (monobehaviour...)

jagged shale Mar 21, 2019, 12:53 AM

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i'll have to sit down with it and the manual or something because apparently 2019 added some crazy new features i don't even get

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like 'subscenes'

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whatever happened to just layering scenes

hollow echo Mar 21, 2019, 12:55 AM

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I assume it's an ECS only thing

jagged shale Mar 21, 2019, 12:55 AM

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maybe. they seem to be valid scenes

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you can open them individually

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but contents is definitely ECS

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everything inside is still using standard LOD groups

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but then those LOD groups are grouped as entries in an outer LOD group

hollow echo Mar 21, 2019, 12:58 AM

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they're controlled via the HLOD component that forces a certain lod

jagged shale Mar 21, 2019, 12:59 AM

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yes and then those are further still in groups that are controlled by the HLOD component

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it's basically just enabling/disabling large groups of items

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https://i.imgur.com/zOhRJxD.png

Imgur

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it's confusing though they gave two different groups the same name lol

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pretty sure one of those should be Medium or something

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maybe that's why the popping is so bad...

lapis plaza Mar 21, 2019, 1:01 AM

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popping is mainly bad because the small objects get too early out

jagged shale Mar 21, 2019, 1:01 AM

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https://i.imgur.com/xWqxL2h.png

Imgur

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both medium and low are low

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they didn't make a medium

lapis plaza Mar 21, 2019, 1:01 AM

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larger shapes lod properly

jagged shale Mar 21, 2019, 1:02 AM

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but i'm surprised they are just using the standard LOD component

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I've always heard it's horribly bad at performance

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maybe that's not true

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because here they are using it thousands of times over

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real stress test

lapis plaza Mar 21, 2019, 1:03 AM

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pretty sure the conversion tool handles those to hybrid renderer

jagged shale Mar 21, 2019, 1:03 AM

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well that's what i was wondering

hollow echo Mar 21, 2019, 1:03 AM

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0lento do you know much about subscenes?

lapis plaza Mar 21, 2019, 1:03 AM

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they are there just for waiting conversion

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like meshrenderers

jagged shale Mar 21, 2019, 1:04 AM

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if ECS had a replacement for those

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so the converter handles more than just objects

lapis plaza Mar 21, 2019, 1:04 AM

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what about subscenes?

jagged shale Mar 21, 2019, 1:04 AM

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it converts components too?

lapis plaza Mar 21, 2019, 1:05 AM

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certain components, yeah

jagged shale Mar 21, 2019, 1:06 AM

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i can at least work with the editor now that it's on my SSD

hollow echo Mar 21, 2019, 1:07 AM

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Just anything, are they entirely a tool to enable streaming? I'm unsure why they exist, in a sense a prefab could be utilised in their place now you can nest them. Why do they seem to be ECS only, is whatever benefit they bring just not relevant elsewhere?

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Is there a resource somewhere that I can't find 😛

jagged shale Mar 21, 2019, 1:09 AM

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yes the way they are used here, they just seem to be a fancy prefab

hollow echo Mar 21, 2019, 1:09 AM

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there's the whole ECS conversion process - and I've heard it's related to that

lapis plaza Mar 21, 2019, 1:09 AM

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they exist because they they also contain serialized entity presentation of that subscene

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so if you load subscene with ecs, you actually load ecs serialized version

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and that's fast

jagged shale Mar 21, 2019, 1:10 AM

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ah

lapis plaza Mar 21, 2019, 1:10 AM

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instead of loading gameobject scene and converting it in place

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I think MegaCity has additional streaming system that takes advantage of this data

jagged shale Mar 21, 2019, 1:11 AM

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was the giant chain in Megacity or a different demo

hollow echo Mar 21, 2019, 1:11 AM

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yeah it's on the side of the pagoda

lapis plaza Mar 21, 2019, 1:11 AM

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but would need to see this gdc's talks to know exactly what the current setup is

jagged shale Mar 21, 2019, 1:11 AM

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ah yeah there it is