Making lit stencils that imprint into the ground?

[Kemerd]

I've searched across the land, and found many a tutorial on how to make a working stencil, but not really something along the lines of:
[video=youtube;IR5DyZa3kEQ]https://www.youtube.com/watch?v=IR5DyZa3kEQ[/video]

How would I go about making the stencil "imprint" sort of part lit up by lighting?

Also, how would I go about making custom shapes? (EDIT: I've been taking a gander at the dynamic mesh creation in gmod, but my main goal is to make a 3D footprint imprint in the ground so I don't know if that's the best way to do it.) Is it possible to use a mask (take a 2d image and just use that as the basis for the shape of the "hole") or something like that? Would I have to make a custom model?

I see stuff like this:
[video=youtube;2FxRfqSd8Cc]https://www.youtube.com/watch?v=2FxRfqSd8Cc[/video]
With custom textures and whatnot.

I know this is a lot to ask, but does anyone have any insight onto this?

Thanks.

[hootiegerbil]

Use a dynamic light for the lighting. Create a mesh with VertexLitGeneric material for rendering the vertices. And use mesh.quad with the stencil functions to allow drawing the mesh inside the wall.