OpenGL picking and finding hitpoint of texture

Question

I'm currently into looking into picking using a ray. I can find which model is selected, but how can I retrieve the position on the texture which is picked? I'm talking about a quad in this case.

Edit: Also, if I want to check whether the hitpoint is transparent/translucent, can I best check this with a shader?

Answer 1

I figure by splitting the quad after getting the specific quad id, then picking again, will give me a point on the quad.