koobas.hobune.stream
Mesh generated at run-time gets frustum-culled too early
I have a mesh generation function that gets called at runtime OR in the editor:
void GenerateAtRunTime() { if (!generated && someCriterion) { GetComponent<MeshFilter>().sharedMesh = Generator.Generate(/* arguments */); generated = true; } }
[ContextMenu("Pre-generate")] void PreGenerate() { if (!generated) { GetComponent<MeshFilter>().sharedMesh = Generator.Generate(/ arguments /); generated = true; } }
if I call it from the editor, all is fine. If I don't the mesh is culled too early: as soon as the center of bounds is out of view, as if it's bounds had size of 0.
The Generator.Generate is like:
Mesh mesh = new Mesh(); Vector3[] v = new Vector3[vtxCount]; Vector2[] uv = new Vector2[vtxCount]; Color[] c = new Color[vtxCount]; int[] tri = new int[triCount];
// .... actually generate here .....
mesh.vertices = v;
mesh.colors = c;
mesh.uv = uv;
mesh.triangles = tri;
mesh.RecalculateBounds();
return mesh;
(I know that assigning triangles recalculates bounds, I'm just that desperate)
as a debugging help I set up the following:
[ContextMenu("Print me")] void PrintMe() { Debug.Log(string.Format("{0} renderer bounds: {1}", gameObject.name, GetComponent<MeshRenderer>().bounds)); Debug.Log(string.Format("{0} mesh bounds: {1}", gameObject.name, GetComponent<MeshFilter>().sharedMesh.bounds)); }
void OnDrawGizmos() { Gizmos.DrawWireCube(renderer.bounds.center, renderer.bounds.size); }
...and bounds seem fine and identical in either case. What am I missing when generating meshes on the fly?
I'm not sure why (and I would like to hear the explanation) but the following has solved the problem: the generator now doesn't create a new mesh but modifies a mesh passed as an argument. Script that triggers the generation has become:
void GenerateAtRunTime() {
if (!generated && someCriterion) {
Generator.Generate(GetComponent<MeshFilter>().mesh, /* other arguments */);
generated = true;
}
}
(if I understand correctly, accessing mesh property creates a mesh when there wasn't one, but apparently it actually does something else to it behind the scene).
I had the exact same problem. And my setup didn't allow me to use your solution.
I knew you were on the right track with the mesh bounds not being handled properly. Since collision with the same mesh worked fine, I reasoned that the MeshRenderer or MeshFilter was the one who needed to be poked.
So I tried playing around with the notifications and it turned out that, this failed:
renderInfo.mesh.RecalculateBounds();
renderInfo.gameObject.GetComponent<MeshFilter>().mesh = renderInfo.mesh;
And this succeeded:
renderInfo.gameObject.GetComponent<MeshFilter>().mesh = renderInfo.mesh;
renderInfo.mesh.RecalculateBounds();
So this is clearly a bug, either RecalculateBounds doesn't work when the mesh isn't attached to a transform, or setting the mesh property of the MeshFilter doesn't update/notify properly.
Use RecalculateBounds() after you assign the mesh to a MeshFilter component. So for example in C#:
GetComponent().mesh = aMeshObject; aMeshObject.RecalculateBounds();
This way it will recalculate renderer bounds.
Had a similar issue, posted an answer on this thread:
See http://answers.unity3d.com/questions/29948/disable-frustum-culling/52479#52479
