PDA

View Full Version : Atlas texture coordinate problem


aso3
08-16-2006, 07:32 PM
Hi,

I'm using LightWave to generate Atlas coordinates for a lightMap. After that, I try to load it into my game engine. However, I often have problems with the texture coordinates it generates. It's caused by shared texture coordiantes. LightWave doesn't seem to have problems with them, by my importer gets confused.

For example, I make a simple box. This box has 6 faces and 8 vertices. That means some of the vertices are shared by 3 faces. When I generate the Atlas texture, you can see this in the UV view; some of the polygons are projected, but are missing 1 or more vertices.

My importer now has a problem. Each vertex can hold 1 lightMap texture coordinate. I don't know exactly how LightWave stores it in the LWO file, but I guess multiple UV coords from that Atlas are now referring to that vertex.

Anyway, the only way to fix this for me, is to seperate the cube faces. I could unweld all vertices to avoid this. But now all the triangles are mapped seperate on the Atlas (taking more space and more vulnerable for artifacts while rendering a lightMap). So, I pick each face by hand, cut it, and
then paste it again so its loose from its neighbours. In case of the cube I get a up,left,down,right,forward and backward face.

This is easy with a cube, but what if the world is far more complex? Is their a more efficient way to avoid these problems?

Greetings,
Rick

mdoyle
08-29-2006, 03:37 AM
Hi,

There can be a workaround, I did this before I think. What engine are you looking to import this into?