Best Practices - Creating a bunch of unique meshcolliders?

Hello everyone!

I've been using DOTS for a little while now and just got into the world of Unity.Physics to replace my old rigidbodies of yore. I have a few objects in my game that I have to instantiate, all with their different and unique meshcolliders (I can't really use boxes because these objects might have holes in them and I need precise raycasting).

I've been trying to add them using code looking like this, but it's horribly slow, am I doing something wrong? And if so, what?

Code (CSharp):

1.  
2. var meshTris = new NativeArray<int3>(mesh.triangles.Length / 3, Allocator.Temp);
3. var meshVertices = new NativeArray<float3>(mesh.vertices.Length, Allocator.Temp);
4.  
5. int index = 0;
6. foreach (Vector3 v in mesh.vertices)
7.     meshVertices[index++] = v;
8.  
9. index = 0;
10. for (int j = 0; j < mesh.triangles.Length; j += 3)
11.     meshTris[index++] = new int3(mesh.triangles[j], mesh.triangles[j + 1], mesh.triangles[j + 2]);
12.  
13. BlobAssetReference<Collider> meshColliderReference = Unity.Physics.MeshCollider.Create(meshVertices, meshTris, Unity.Physics.CollisionFilter.Default, Unity.Physics.Material.Default);
14.  
15. Entity source = entityManager.CreateEntity();
16. PhysicsMass pm = PhysicsMass.CreateDynamic(meshColliderReference.Value.MassProperties, 1f);
17. entityManager.AddComponentData(source, new PhysicsCollider() { Value = meshColliderReference });
18. entityManager.AddComponentData(source, pm);

Many thanks!

 

Unfortunately mesh creation is a slow process, especially for large meshes with a lot of triangles. You could put mesh creation part in a Burst compiled job, that should speed it up significantly. Check CreateTempMeshJob in PhysicsShapeAuthoringEditor.cs for usage.

 

Would approximation of your mesh collider with compound of convex colliders be a viable option?