...or something like that!
Need some help. I'm trying to add some interest to a simple 2d chalk sketch of a city. In the patch below, I've loaded the image as a texture and via gl.nurbs have warped it a bit. Then changing the camera angle I can fly around my fake 3d city.
My problem is that as the image begins to wrap upon itself (by changing the camera angle), there are some horizontal planes that appear that are transparent if you are looking from above, opaque if looking from below. In patch below with the sample image illustrates this better than I can explain. Rotate the image and you'l start seeing the upper planes at ~50°.
So my question: how do I make these planes transparent on both sides. And a related question...where are these planes coming from? From gl.nurbs?
Thanks in advance!