Slippery physic material causing issues

[gleaming socket]

as you can see here i have a slippery material (0 dynamic and static friction, as well as minimum friction combine) on the ramp's collider

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if you collide with it and continue to add forward force then the player not only moves to the side but also for some reason moves upwards 🤔

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it would be fine if it was going to the side but i dont understand why its going up

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my player is set up like this:

head - sphere collider
body - box collider
arms and legs - capsule colliders

the player also has a rigidbody on it, and the movement is physics based

[barren vigil]

OK, so... imagine you have a ramp and drive a car at it, the car goes up the ramp and you can do a Dukes of Hazard stunt jump, right?

You're asking what makes the car go upwards when it was only driving horizontally?

Or am I misunderstanding the question?

[gleaming socket]

well of course this would be happening because the ramp is at an angle

right

?

but in the video i am approaching the ramp from the side, so it should act like a wall instead of a ramp

[barren vigil]

You'd think so.
It's likely one of two things...

It's a simulation, so not perfect. Or sometimes too perfect.
So floating point errors or the like could be pushing it slightly.
Then, depending on the physics settings, you get unrealistic behaviour.

[gleaming socket]

ah

have to mess around with some numbers then im guessing 🤔

[barren vigil]

The other likely culprit is your character controller.
They often have code to do things like lift you upwards if you're slightly too low. For steps or ramps or stuff.

[gleaming socket]

i do not have a character controller on my player

only my own movement code

and rigidbody

not fully my own code ofc, mainly from a tutorial

[barren vigil]

With no friction on the wall, and your sideways movement keeping you pressed against it, you might be "sliding" upwards from the character controller pushes.

[gleaming socket]

if i increase the mass of the rigidbody maybe that could fix it?

or maybe increase gravity

[barren vigil]

What stops you falling through the ground? Just colliders?

[gleaming socket]

yeah

[barren vigil]

NO! Set it to 9.8 and never touch it!

[gleaming socket]

oh 👀

whys that

[barren vigil]

Unless your game actually has changing gravity, like in a space station.

[gleaming socket]

ohh

no i meant the gravity of the rigidbody mb 😅

[barren vigil]

Because everything you can do by changing gravity, you can do by changing other settings.
If you change one, it effects everything.

[barren vigil]

Ah, that's more OK, but I'd still avoid it unless you want to tweak physics.

[gleaming socket]

hmm

[barren vigil]

Change the mass.

[gleaming socket]

ill try that

one second

[barren vigil]

You can get great effects by playing with gravity for things like double jump or air hang time.
Like if you have a ground smash attack, you could increase gravity for the fall to make it feel more powerful.

[gleaming socket]

increased mass to 10 and my player couldnt move, then i multiplied the speed by 10 and it moved fine, but the problem still occurred

[gleaming socket]

mmm

interesting stuff

seems like changing mass doesnt affect it
it irritates me that i have to make the materials slippery, because if i dont then my player gets stuck to the side of the ramp and under the ramp upon collision, and it takes a couple seconds of holding down the "move back key" to get unstuck

[barren vigil]

OK. So the up is either something else, or caused by the sideways push.
What if you stop pushing, does it keep lifting or start falling?

[gleaming socket]

let me try

[barren vigil]

What if you put a box/wall that isn't angled, does this happen?

What if you put a tiny friction?

[gleaming socket]

by the way, i shouldve said this earlier, this only happens if i approach the side of the ramp from near the lowest part of it, if i approach it from the "middle of the side" then it doesnt happen

[gleaming socket]

begins to fall down

[barren vigil]

I'm hammering you with the questions because I don't know what the problem is, but have ideas, trying to narrow it down.

[gleaming socket]

yes this is a good way of figuring out problems

[gleaming socket]

nope

[barren vigil]

You're using a capsule collider, right?
This makes me think it's hitting the curved bottom and getting that upwards push.

[gleaming socket]

thats what i was thinking too

but if i make it a cube collider then the player doesnt deal with ramps very well

[barren vigil]

Yeah, and that's why it's not happening on the wall.

[gleaming socket]

hm

[barren vigil]

I have a different, personal solution.
But we can try to sort it out with the capsule.

So, what mass do you have set?

[gleaming socket]

you can put forward the personal solution too if you think it is better 🤞

[gleaming socket]

1

[barren vigil]

Let's try to put in realistic values.
This is a character, right? So use maybe 80 or 100?

[gleaming socket]

yeah

ill increase the speed and jump force too

[barren vigil]

Yep

[gleaming socket]

thats done

[barren vigil]

If we keep the physics values approximately realistic, you can "guess" values by googling.

[gleaming socket]

mhm

[barren vigil]

Let's also set some friction for your material. Unless you literally need it frictionless.

[gleaming socket]

gravity is at -9.81 btw

[gleaming socket]

nono friction is fine

i have it at 0 currently with minimum friction combine

[barren vigil]

I don't know what real values are, so google. I'm on my phone.

[gleaming socket]

alright

around 0.4-0.6

unity had it at 0.6 for default

[barren vigil]

Sounds good. So let's use that range. Slippery surfaces might go lower, but we have a ballpark.

[gleaming socket]

mm

does the speed of the player need to be realistic 🤔

[barren vigil]

How's it looking now?
Same problem? Has the movement or timing changed?

[gleaming socket]

its currently at 7m/s

[gleaming socket]

let me test it rq

[gleaming socket]

well the movement and timing is fine, and the sliding upwards problem is gone

[barren vigil]

No, but bear in mind the results will match the value.
So a fast player will launch themselves off the top of a staircase as if it's a stunt ramp.

[gleaming socket]

however this caused the problem that i said earlier

that when my player goes underneath the ramp, it basically gets stuck

but i think i know why this is happening

my idle animation and running animation cause the head to move up and down a bit, so when i go under the ramp maybe the head is still trying to move which is causing issues with the colliders

ill try and see how it works without animations

[barren vigil]

Yeah, that's "normal" physics, objects get jammed.

We can fix it separately.

Are your colliders on the character head?
If you're using a capsule, there's no head, right?

[gleaming socket]

ah, so whats happening is that when i am stuck under the ramp, if i try to move back out, i can do it easily, however if i try to move back and sideways at the same time, then it starts to move very slowly

[gleaming socket]

sphere collider on the head

capsules on arms and legs

and cube for body

[gleaming socket]

without animations by the way

[barren vigil]

Why? & are you using physics layers?

[gleaming socket]

let me do a bit of testing one sec

[gleaming socket]

no im not using physics layers

and i thought a sphere collider would help in a situation like this 😭

yeah the animation is defo part of the problem

[gleaming socket]

well ill be honest i dont even know what those are, so no i dont believe i am using those

[barren vigil]

OK, so in general the way we'd normally do this is:
Character control just uses a capsule for collision. Ignore the character and animations. Keeps things faster and more predictable for movement.
Then the character has colliders on it, which we use for shooting, animations where it hits things, particle effects etc.
We use physics layers so the capsule ignores the body colliders, and the body colliders ignore the capsule.

[gleaming socket]

ohhh

so theres one big general capsule collider for movement, and then smaller ones for the more specific things

?

[barren vigil]

Sometimes you don't even need the body colliders.

[gleaming socket]

and the physics layers are so that the capsulecollider doesnt interact with the smaller ones?

interesting

[barren vigil]

Yes

[gleaming socket]

i will try that now, and let you know how it works

[barren vigil]

And so we can tell code which colliders we care about

Imagine shooting your character. It's going to hit the capsule before it hits the characters head, right?
If they're on the same layer, what's the point of having that head collider?

[gleaming socket]

yes true

but tbf you can use the head collider for things like headshots

oh wait

i misunderstood the question

mb

[barren vigil]

Yes, but only if it's in a different location to the capsule. If it's "inside" the capsule we wouldn't get the head shot because we'd hit the capsule shell.

[gleaming socket]

which is why we use layers, as you explained 👍

[barren vigil]

Yeah

[gleaming socket]

adding a capsule collider to my player object causes the location of the toolhandle to change 🤔

nvm

[barren vigil]

If you wanted to keep it simple, you could make the capsule shorter and put a sphere above it for head shots.
If the exact accurate colliders aren't needed.

[gleaming socket]

good idea

[barren vigil]

But for a game like fortnight you'll need colliders on the body that move with the animation.

[gleaming socket]

oh

i am making a game like pixel gun 3d, not sure if youve heard of it

basically minecraft with guns and no building

so i guess i do need colliders which move with the body

[barren vigil]

So with the body colliders turned off, you don't get stuck?

[gleaming socket]

hold on im nearly done 👌

[barren vigil]

I haven't

[gleaming socket]

should i keep the animations on or off?

[gleaming socket]

ok, so when i go underneath the ramp, and then move backwards, i can move out

if i continue to apply a forward force as well as a sideways force, i move to the side VERY slowly

howver thats not too much of a problem tbh

[barren vigil]

That's normal. You're pushing against the wall.

[gleaming socket]

yep

[barren vigil]

Same thing happens in real life if you try to walk through a wall 😉

[gleaming socket]

so if i am running into a wall and trying to move sideways at the same time is it possible to make it so that it moves to the side?

[gleaming socket]

LOL

true

[gleaming socket]

actually wait

[barren vigil]

Yes

[gleaming socket]

ive noticed this mechanic is not actually present in any games

so its fine

in fortnite for example if you are running into a wall and try to move sideways it wont go fast

i think my problems are fixed then

[barren vigil]

Exactly

[gleaming socket]

thanks a lot

[barren vigil]

But yes, you can give a little sideways push. Or you can stop the pushing in the wall direction.

[gleaming socket]

mhm

[barren vigil]

That's useful when players clip the wall when going through doors.

[gleaming socket]

can i ask one more question

[gleaming socket]

ah

[barren vigil]

Just nudge them, and they think it was their own skill.

[gleaming socket]

🤣

[barren vigil]

But that's just polish. It's layered on top of the game, not something you need.

[gleaming socket]

yeah pretty much

need to get the basics done

[barren vigil]

Yeah

[barren vigil]

So, I don't suggest this, because I don't know anyone else who does it. So it'll be hard to find tutorials and other problem solving help...

But what I sometimes do is make a floating sphere for the player.

It detects the ground distance and pushes upwards, but there's no colliders touching the ground.

Then I totally sidestep (ha!) all problems with getting stuck on ground rubble, stairs, the corner of ramps...

[gleaming socket]

oooo

[barren vigil]

And the upward force can be like a spring. The closer to the ground you are the stronger it pushes.

So it gives this natural bounce.

[gleaming socket]

smart

[barren vigil]

Jump down and you lower to the ground then bounce back upwards. Sometimes with a little jump.

Run up stairs and you keep going up for a moment, with that feeling of momentum.

[gleaming socket]

so it makes it all feel really realistic

[barren vigil]

You do have to use IK to place the model feet, because you can't use the character position to know where the ground is.

[gleaming socket]

inverse kinematics

ive heard that before, not sure what it is yet

will have to look into it

[barren vigil]

I'd say "dynamic" - it's not necessarily realistic.
It depends on what feel you want.

[gleaming socket]

for ground check i just use a raycast from the center of the character pointing down with a length of half the characters height + 0.2f

[gleaming socket]

mm

[barren vigil]

Check out spherecast.
Same idea, but it's a "fatter" ray.

Otherwise if you walk over a small gap, the ray might think you're falling.

[gleaming socket]

oh yeah true

ill look into that

[barren vigil]

Good luck. You're in for a lot of fun 🙂

[gleaming socket]

the body colliders and the large capsule ("movement collider") should no longer interact, correct?

this is my first time using physics layers

[gleaming socket]

thanks for the help 🙏

[barren vigil]

My pleasure

[barren vigil]

You can probably disable the body colliders from interacting with everything.
Since you're not using them to push or to be pushed by anything.

[gleaming socket]

oh yeah i didnt think about that

they will only interact with bullets

[barren vigil]

Otherwise the body can still get stuck with the ramp etc.

[gleaming socket]

👌

[barren vigil]

If you're interested, here's what the floating ball movement looks like 🙂