RenderMeshUnmanaged not rendering procedural mesh

Unity Engine
, , , , ,
1

I am trying to render procedural meshes using RenderMeshUnmanaged and RenderBounds. First I create the entity:

entitymanager.AddComponentData(chunkEntity, new LocalTransform
{
    Position = c.ChunkOriginInWorldSpace,
    Rotation = quaternion.identity,
    Scale = 1,
});
entitymanager.AddComponent(chunkEntity, typeof(LocalToWorld));


entitymanager.AddComponent(chunkEntity, typeof(RenderMeshUnmanaged));
entitymanager.AddComponentData(chunkEntity, new RenderBounds());

Then I generate the mesh and update the components here:

entitymanager.SetComponentData(chunkEntity, new RenderMeshUnmanaged(mesh, mat));
entitymanager.SetComponentData(chunkEntity, new RenderBounds { Value = new() { Center = mesh.bounds.center, Extents = mesh.bounds.extents } });

And yes, I have verified that the same exact meshes render with the same exact material as GameObjects.

2

RenderMeshUnmanaged is bake-time only, and baking systems iterate over it to add the real required components. It doesn’t do anything at runtime. I think what you are looking for is RenderMeshUtility.

3

Ah I have used RenderMeshUtility for creating entities. How do I update an existing mesh? It only have AddComponents. Do I need to maintain a global renderMeshArray, change the mesh in its array or something?

4

MaterialMeshInfo is what you want if you are looking to swap out meshes and materials at runtime. If the mesh is newly-generated, you will need to register it to get a runtime ID.

5

Is there a way to De-Register or modify a mesh during runtime?

6

Yes. You can deregister a mesh the same way you register it. But also, you do not need to deregister and reregister a mesh if all you do is modify it. You modify it with the Mesh API, just like GameObjects.

7

I see. So that implies that I should be able to initialize an entity with a new Mesh() in the RenderMeshArray, assign it using the RenderMeshUtility, and then at runtime just update the mesh data without having to change the MaterialMeshInfo mesh index or register a new mesh, right?

Thanks for the clarifications!