public class Sandbox.Engine.Shaders.ShaderCompile.Results.Program

If you're just opting for default Vertex and Pixel inputs which are usable on the default shading model, these are the reference member variables for each:

The FilmGrain component adds simulated film-style grain to the camera output. It's purely visual – it does not affect gameplay or lighting – and is intended to add texture, grit or stylistic noise to the final image.

This section needs to be rewritten with an explanation of all the code, libraries, etc.

The "Model Editor", also known as "ModelDoc", is where you can create and edit model (VMDL) files. This is the modern equivalent of Source 1's .QC files. You can find it under the "Tools" menu.