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View Full Version : Wrong colour when map tex and Disappearing faces



crimsonshade
03-21-2005, 07:25 PM
Two problems that i havn't been able to solve are:

When a texture is mapped to a face, all yellow and shades of yellow are changed to blue and shades of blue.

With all of my faces, at certain translated camera points they will disapper sometimes only half disapper (as in only part of the face is visible) for no reason, has been tried on two computers with the same results(two different graphics cards). There are no other faces to obsecure these faces.

This is a non-technical description, just want to see if they are common problems before i post a longer desc, that and i have a lector in 5 minutes.

Crimson Shade

mikael_aronsson
03-21-2005, 10:50 PM
Hi !

Any blending involved in the textures ? and what is the color of the surface you map the texture on ?

What do you mean with "faces", do you mean that you only see partial triangles or do you loose one or more triangles of a surface ?

If that is the case make sure that you got the winding order correct so that the triangles are facing the right way (if you see the back side of a triangles and you cull back facing triangles you will not see them).

If that's not the problem, make sure you clear the depth buffer at each frame so you don't get some crap remaining in the depth buffer.

And if that's not the problem either, post a screenshot.

Mikael

03-22-2005, 01:18 AM
The first problem sounds like a RGB vs. BGR issue, the other like a near-far clipping plane issue.

If you could post a screenshot and/or some code, it would be much easier to troubleshot the problems.

dvm
03-22-2005, 04:14 AM
Yes, check your view frustum, it's probably too small.

crimsonshade
03-30-2005, 07:35 PM
Sorry it took me so long to reply, i still dont have the net at home.

I did some more exploring in my spare time, my near and far clip is 0.0 and 60.0 and the objects are well inside that range, so this is not the problem.

When i set the bitsperpixel to 16 (instead of the original 32), there wasn't a problem with disappering faces. So i did a search in the forums and cant seem to find anything related. Turning textures on and off never effected the outcome.

I originally thought it was the RGB, BGR problem and i cant remembered if i tried it out... Ill try it when i get back home and post here again in about 30 minutes.

Crimson Shade
Ps. thanks for far

03-30-2005, 10:26 PM
Putting z-near at 0.0 isnt a very good idea and will kill your z-buffer precision:

http://www.sjbaker.org/steve/omniv/love_your_z_buffer.html