View Full Version : Very urgent question about alpha and lighting

11-11-2003, 11:13 AM
Hi there!

Hope you can help me and somebody of you have had this problem before.
here some pics: http://www.bollwerk.at/neu/gfx/temp/planet1.jpg http://www.bollwerk.at/neu/gfx/temp/planet2.jpg http://www.bollwerk.at/neu/gfx/temp/planet3.jpg

Picture 1:
This is what it should look like... the clouds are transparent.
Picture 2: This is what it looks like seen from some angles - you can see through the planet (although it has a alpha value of 1.0!!!)
Picture 3:
So, sometimes it looks like this!

Have you encountered such problem before?

I can provide you with further information if you want!



11-11-2003, 04:35 PM
I'm trying to figure out transparencies myself,
Picture 3 looks like you might have a problem with the mesh (model) it could be the normals are not correct, or the mesh is corrupted
sorry i cant help any more than that

11-11-2003, 10:30 PM
I think I fixed that with CULLING or so http://www.opengl.org/discussion_boards/ubb/smile.gif

now it works great http://www.opengl.org/discussion_boards/ubb/smile.gif


11-13-2003, 11:55 AM
Uggg... seen this problem several times when i was a beginner.

It has to do with the depth buffer and its acurricy, which is a ratio of near and far of the perspective. Try setting Near to 1 or 0.5, and far as close as possible, this will help.

Culling is just a way to get around it, i'm not saying it doesn't work, i'm saying you'll run into more problems later in the program.