Replace output nodes of a built-in visual TSL Points, Lines, GSplats, or Mesh
material (excluding physical meshes and picking materials).
The callback sees the latest Luxar graph on registration and every rebuild;
return only the outputs to replace. Passing null restores the base graph.
The callback is retained when the material is cloned.
If the callback throws during a rebuild, that variant uses its base graph;
the callback stays registered and runs again on the next rebuild.
Vertex and depth overrides affect the visual pass only: picking continues
with Luxar's built-in positions and depth.
Replace output nodes of a built-in visual TSL Points, Lines, GSplats, or Mesh material (excluding physical meshes and picking materials). The callback sees the latest Luxar graph on registration and every rebuild; return only the outputs to replace. Passing null restores the base graph. The callback is retained when the material is cloned. If the callback throws during a rebuild, that variant uses its base graph; the callback stays registered and runs again on the next rebuild. Vertex and depth overrides affect the visual pass only: picking continues with Luxar's built-in positions and depth.