The pass-through shader shows the basic structure of a geometry shader but it doesn’t really do anything exciting.

Let’s modify it to make a duplication shader, which will duplicate an object and translate it by a vector.

First, let’s change the vertex shader so that it passes through the vertex positions.  We’ll apply the modelview and projection matrices to compute gl_Position in the geometry shader instead.

Vertex shader:


In the geometry shader, we’ll duplicate each triangle and apply a translation.

Geometry shader:


Result:

High