What do purple patches in potato mode mean?

My untextured mesh normally appears all white in potato mode but one of my models has purple patches on it. The normals are fine and I can’t see what’s wrong. Also, sometimes my real-time textures are messing up. They flip between messed up and ok when zooming and selecting stuff - is this an ATI thing? Here are some screenshots (hit return in the location bar if the page fails):

here the texture in the back messes up:
http://www.geocities.com/ajr650/purplebadtex.png

here it’s ok:
http://www.geocities.com/ajr650/purplegoodtex.png

here some purple patches have a gradient - see the dashboard:
http://www.geocities.com/ajr650/purplegradient.png

Is the purple vertex colors?

Thanks R2Blend, it appears it is. Funny, I don’t remember painting any vertices. I must have painted one vertex by accident or something and then just kept extruding it. %|

Does anyone know about the textures messing up? My whole Blender window goes like that when I render and in the new version when I go into the dock. Like this:

http://www.geocities.com/ajr650/Blendermess.png

What card do you have? Maybe you should try turning off anti-aliasing, or upgrading to a new card.

I have an ATI Radeon 7500 mobility with 16MB VRam. I’ve turned off mipmapping/antialiasing in the user prefs but I think I did that before and it made no difference.

It’s hard to tell what’s causing it because it’s intermittent. Sometimes it goes away if I restart Blender. The thing is, a few OpenGL programs I made did this when I maximised them. Blender does it more often. Very puzzling.

I hate to tell you this, but I think you need a new graphics card. Even my ATI all-in-wonder Radeon 8500dv is old.

Do you get a similar effect with your card? I didn’t think it was the card because I can play most low-end games at a decent fps - I managed to get Soldier of Fortune 2 to work a while ago but only just.

I think you’re right though, the textures only seem to mess up when I do something else that uses OpenGL and since nearly everything in Mac OS X uses it including the interface, pretty much everything I do affects Blender at some point. I suppose I could use 16 bit colour but I’d rather suffer the intermittent problem - it doesn’t happen too often. I was just checking it wasn’t an ATI driver issue because a few people have had trouble with them.

Thanks again for the help R2Blend.

I got it once while playing a blender game.

uv-mapped objects turn pink if you have an image assigned, and then remove it (so that blender doesn’t find it any more). happened recently to me - i was browsing some older files with “outdated” image references (either moved or deleted textures).