Render pass lambda captures storing outdated material variables

[cjhoward]

Currently some render passes, such as the material pass, capture material variables as shared pointers in lambdas. However, sometimes a material's variables are changed or a material with the same hash but different variables is created, causing outdated material parameters to be passed to a shader.

The whole model of storing shared pointers to material variables in lambda captures is messy, confusing, and leads to difficult-to-track bugs. The material variable and shader variable interfaces need to be redesigned to be less bug-prone and easier to use.

Also take into consideration that the individual shader uniform model should be phased out in favor of uniform buffer objects.