NodeMaterial: Material.onBeforeRender()

[sunag]

Description

The new NodeMaterial system work isolate of WebGLRenderer for creating of normalView, positionView and others for that the same code can be work in WebGPURenderer too.

For this done correctly, is needed a frame update for the nodes, this update can be done in with Material.onUpdate() or Mesh.onBeforeRenderer() for example.

Material.onUpdate(): was my suggestion, this new feature is much similar with the recently implemented Material.onBuild() #21117

WebGL NodesMaterial support

• normal

Update webgl_materials_standard_nodes example.

[mrdoob]

Thanks!