In Reality Composer Pro Shader Graph Material you can specify the coordinate
space of an input position as “model”, “object”, “tangent”, and “world.”

Coming from an OpenGL background I am used to thinking of coordinate systems according
the model, view, and projection transforms:

• model or object space : original / untransformed coordinate,
• word space : coordinate transformed by the model transform,
• camera or view space : coordinate transformed by both the model and view transform,
• clip space : coordinate transformed by the model, view, and projection transform

I also understand how to build an GLSL shader so that the point is described in the local vertex’s tangent space. What I can not find in Apple’s docs is any definitive explanation of the model, object, and world coordinate spaces? Can anyone explain?