Position-only vertex buffer for shadow map / depth prepass

[JMS55]

What problem does this solve or what need does it fill?

Non-position vertex attributes are not necessary for depth-only views like shadow map views or the depth prepass.

Separating vertex buffers into one for positions only, and one for everything else, may improve cache performance for depth-only view rendering.

We'll have to see if it's worth it.

What solution would you like?

Have one vertex buffer for positions, and a second vertex buffer for everything else.