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View Full Version : Strange Bump Map Behavior...



RonB
02-14-2006, 07:08 PM
Having this strange reaction...never know when or why it will happen. The image below pretty much shows what's going on. This happens for no apparent reason from one render to the next. Maps on the outer carton were changed but the bump map is the same and settings are the same...it may happen or it may not...it's driving me nuts. It will definately happen if I rotate the object to get an angle shot done. After the rotation I auto fit all the textures to make sure, but this bump gets large upon rendering for some reason. Anyone have any ideas at all? I'm on a PC LW 8.5. Thanks much, Ron

http://www.dahothouse.com/work/example.jpg

Gettarobox
02-14-2006, 07:43 PM
wonder if it's some kind of moire type thing

RonB
02-15-2006, 10:03 AM
Yeah, I don't know Getta...how that would affect the map though baffles me. It must be some sort of bug...I've never seen anything like this before.
Thanks, Ron

Weepul
02-15-2006, 01:41 PM
I experienced a problem like this trying to do the same thing with a texture like that and had no idea what was causing it or how to fix it.

Not that helpful, I know...

Hoopti
02-15-2006, 05:42 PM
I've only seen this when the mapping mode of the bump map doesn't exactly match with the model. I had it happen on a model that wasn't located at dead center 0,0,0 and had the mapping mode setup right. I wasn't using a circular model but when I changed that, I actually got it to work.

Hope that helps somewhat.

Hoop

RonB
02-15-2006, 07:18 PM
Weepul and Hoopti,
As far as I can figure it was the same problem as Hoopti's. I went into the model from the top, it's a bottle, went into micro mode as far as I could and found that the top and bottom points from the lathe were off from each other. Neither were at 0,0,0, so the model had a tiny warp to it. Also found doubled polys in the cap. I fixed both and tacked the bump and spec maps down with a UV map. So far it looks good with 3 renders done...amazing how the smallest little thing influences so much. Gotta be spot on with the geometry.

Thanks for the input guys!
Ron