Extensions needed for CSGAutoColliderAddBuildProcessor.cs

Extensions.cs

public static class UnityExtensions
{
  public static Transform FindDeepChild(this Transform aParent, string aName)
  {
      Queue<Transform> queue = new Queue<Transform>();
      queue.Enqueue(aParent);
      while (queue.Count > 0)
      {
          var c = queue.Dequeue();
          if (c.name == aName) return c;
          foreach (Transform t in c) queue.Enqueue(t);
      }
      return null;
  }
  
  public static Material GetMaterial(this RaycastHit hit)
  {
    MeshCollider collider = hit.collider as MeshCollider;

    if (!collider)
        return null;

    Mesh mesh = collider.sharedMesh;

    // Finds the submesh that contains the hit triangle
    int submesh;
    for (submesh = 0; submesh < mesh.subMeshCount; submesh++)
    {
        var submeshInfo = mesh.GetSubMesh(submesh);
        if (
            hit.triangleIndex >= submeshInfo.indexStart
            && hit.triangleIndex < submeshInfo.indexStart + submeshInfo.indexCount
        )
            break;
    }

    MeshRenderer renderer = collider.GetComponent<MeshRenderer>();
    
    if (!renderer)
      renderer = collider.GetComponentInParent<MeshRenderer>();
    
    if (!renderer)
        return null;

    return renderer.sharedMaterials[submesh];
  }
}

hello, thanks for writing this! i noticed the call to mesh.GetTriangles(submesh) adds 4kb of garbage in profiling, so i optimized the logic a bit and it got down to just 40b (seems like accessing sharedMaterials at all does that)

        // Finds the submesh that contains the hit triangle
        int submesh;
        for (submesh = 0; submesh < mesh.subMeshCount; submesh++)
        {
            var submeshInfo = mesh.GetSubMesh(submesh);
            if (
                hit.triangleIndex >= submeshInfo.indexStart
                && hit.triangleIndex < submeshInfo.indexStart + submeshInfo.indexCount
            )
                break;
        }

Nice find! I'll swap it out for future peeps 👍