uv vs. materialuv

[madebygeoff]

Not the most urgent of questions, but it's been bugging me and I can't find very good documentation. What is the different between UV (vertex attribute) and materialuv (point attribute). They seem to function similarly and interchangeably when applying textures, but other than the fact that one is point and one vertex, I don't see a difference. So why does Vellum apply materialuv's to its materials instead of uv's? Is there any real difference?

[anim]

'uv' vector attribute vertex or point is commonly used as texture lookup coordinates in many dccs it's vector2 in houdini usually vector3, but ultimately it's just a vector attribute called 'uv', you can have vector attribute of any name and still bind it in material and use it to look up textures (images, volumes, procedural patterns) so that means that vector attribute 'materialuv' would work the same way, so does commonly used 'rest', etc. 

'materialuv' vector attribute however is a point vector attribute that vellum recognizes by default for computing anisotropy for stretch constraints used by Warp/Weft parameters for cloth

similarly 'materialuv' vector point/vertex attrib is also recognised by FEM solver for anisotropy for polys or 'materialuvw' for tets

in other words it's meant for physical material properties not shading material as 'uv' even though you technically can use either of them for both