Cant get uv6 to bind to mesh and work on CustomMaterial

I am trying to refine my GPU LOD stuff so I can use multimats and fade between LOD layers.

But for some reason I can not get the uv6 attribute to bind. Line 170 is where it supposed to happen and I add the ref on line 198 to the material.

But for some reason its dropping an error that there is no uv6.
This is related to https://playground.babylonjs.com/#UF776R#20 but the first PG is the one I’m referring to and is a bit different in structure to make it easier to load meshes into the system. Just gotta figure this step out. This second one is just for reference.

@nasimiasl might know ?

AddAttribute don’t add the declaration for you in the vertex shader, so you need to add attribute vec2 uv6; in the Vertex_Definitions section.

i just use uv1 in standard material don’t know that support uv6
also custom material have all standard material limits

if you can move to nodeMaterial maybe that can be better