Vertex arrays or display list?

OpenGL OpenGL: Advanced Coding
1

Hello

I have a rendering performance question concerning vertex arrays and display lists:
I have to render a face which consists of about 100000 triangles. I can turn the head araund (i’ve implamented a trackball) and now, I’d like to implement a routine
which will allow me to paint on the head(->I’ll need a picker which will give me the actually picked triangle). Until now, I’ve implemented the display function with vertex
arrays (for vertex, texture coords and normals). Now, my question is: Would it be faster to implement the whole rendering using a display list? What is exactly the
difference (I don’t change the geometry, so the use of display-lists is possible)? Or should I implement the picking with a diplay list, because during picking only the
triangles have to be painted, not the texture and the normals,. and the normal display method using vertex arrays?
Thanks a lot for every hint

Philipp Staempfli, student of Computer science. ETH Zuerich

2

You’re right, display lists are good for static data. But static data implies no changes at all. You can perform operations on the whole display list but not parts. So I don’t see how you could paint individual triangles of the mesh if they’re in a display list. I’d stick with vertex arrays, which are also a great way to render your data performance wise. Someone else may know of a way to get around your problem but I don’t.

3

Well, I actually don’t have to change my triangles, the only thing I change during painting is the texture (glTexSubImage)… So my geometry-datas are static…