Increasing the thickness of a triangles

Hi everyone, I want to make a function that increases the thickness of the triangles of a mesh. The project I am working on includes certain triangles that are selected with respect to colour, for example all the meshes that are coloured red are considered selected triangles. I want only the triangles that are selected to increase their thickness.

I just want the method to increase the thickness of the triangles of a mesh!

A mesh ist a collection of faces, which have a “thickness” of zero. Just like a mathematical “point” has a width/height of zero.

If you want to extrude a 2D face into a 3D body of a certain width (height), have a look into this function:

I understand your point but the issue I am facing is that I want to do something that can give an effect that the selected area just got thicker. I had an idea to copy and paste the selected triangles by increasing their offset a little bit but that will require way too many copies.

About Extrude Geometry, I am familiar with it but the issue is that I want it to be on a Buffer Geometry because I am using shapecast on it.

The concept of “offset” is inherently a 2D-one. Three.js is not meant to do that.