timber stag
Hi everyone!
I have followed the tutorial for the A* pathfinding algorithm from CodeMonkey and have got the script running. However, I went onto looking at the ECS and have seen that it is in experimental. I know that using ECS is more "efficient", however is there a way to pass gameObject data into the script or not? If there is, would anyone be so kind as to talk me through how to do it. I haven't found many resources on this. I will post the script below, sorry its long.
vital bear
You have to modify this (alot)
Right now it's literally just running 20 path calculations from a set start position to an end position every second
timber stag
yes I used that for testing the algorithm
timber stag
not at the moment no
vital bear
or path nodes sry
timber stag
nope
vital bear
You have to divide your map into a grid and check which cells are walkable
timber stag
To make the cells not walkable I would have to manually do this is code though right?
by setting the bool
vital bear
Yes, but you can automate it using physics casts
so you basically run a collision check on every cell and see if there's another collider there
timber stag
Alright, so how would I do this with a tilemap then? Because do tilemaps have colliders?
vital bear
With a tilemap you can use GetTile too see which type of tile is at a specific position. Then you'd have a list of walkable and non-walkable tiles and compare it against that
You could also use the physics casts and attach a tilemap collider
timber stag
Perfect, okay. So I now know how to do that. What about the ECS then, should I just not use it and just use DOTS
vital bear
Don't use ECS
timber stag
Okay, I'll reframe from using it
vital bear
you can stick with Burst and Jobs since it wiil improve your performance
timber stag
Alright, I may be back with more questions soon lol
timber stag
its just a bit more complicated
I know, I started to cry when I saw it
timber stag
Imagine I have multiple of the same type of enemy in a scene. But each of them needs to path find from a different location to a different end location. How would I pass all these jobs into one scripts and then get them all to complete at once using multi threading?
vital bear
Just have the script on all enemies and start one job per. Complete them in LateUpdate or in a later frame to get them all to run in parallell
timber stag
So have a copy of the PathFinder script in every game object?
vital bear
Yes
You want to create the grid in some manager script though
And share it between all your pathfinders
vital bear
Why would it be? They barely contain any data
timber stag
true, good point
could I hold the pathfinder in the scene by itself like in a manager?
timber stag
yes but I'm not sure how to go around it
vital bear
But that sounds like unnecessary complexity
Think about how many enemies you will want to have and the size and complexity of the map
Computers are fast
timber stag
I want maybe, 200+
vital bear
Oh thats actually a lot
timber stag
a few yeah
vital bear
Are they all pathfinding to one point?
timber stag
once they get in a certain range of the player then they start pathfinding to the player
and then I'm going to add a roam function
vital bear
Alright
I say try the performance of A*
but otherwise there is the flow field algorithm which works great when a lot of enemies move to one point
You could also do a mix of them
timber stag
I didn't want to limit myself with an algorithm that would only pathfind to 1 point which is why I went for A*
Anyway, how would I make my gameobject pass its position into the job and then spit out the path back to the hgameobject
vital bear
Make a float3 field in the job
timber stag
thats fine I'll do a little rounding
vital bear
Then return a nativearray/list of int2
timber stag
so here can I change void in execute to a Native List of int2?
timber stag
Would this work?
timber stag
I still can't get this path outside of the job and its starting to annoy me lol
surreal hazel
I still can't get this path outside of the job and its starting to annoy me lol
See the example, you need to allocate a native container when setting up the job, pass it into the job, use it in the job and then you can use the result once the job completes
timber stag
https://docs.unity3d.com/ScriptReference/Unity.Jobs.IJob.html
I've tried this and I just get given a null array every time
I've got this and passed an array but idk what to do now. I feel like I've done everything
surreal hazel
I've got this and passed an array but idk what to do now. I feel like I've done ...
you're not using the results list in the job
you need to fill it with the paths
you are only setting the field to the new Temp one created in the job
don't do that
just send the results list into the functions and fill it, don't create a temp one
so use CalculatePathVoid() line 287
but don't do line 295 (or line 291) do results.Add(...
