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diginime
06-23-2006, 02:38 PM
Hi, i created a sphere and i apply a bump onto it (The pic sure is black and white). Then i found that the bump that formed and the bulge area is black area in my pic and the opposite. But when i created a grid instead of sphere, the bump that formed and the bulge area is the white area in my pic, what's wrong with this? Can anyone tell me what colour actually make them bulge, is it white? Then i try displacement, it works well either in sphere or grid, both bulge area is the white area in my pic.

This pic is using sphere and i apply a bump onto it. The Black area bulge instead of white.
http://img133.imageshack.us/img133/6669/untitled12gv.jpg

This pic is using grid and i apply a bump onto it. The white area bulge.
http://img133.imageshack.us/img133/5870/untitled28hk.jpg

This pic is using sphere and i apply displacement onto it. The white area bulge. http://img390.imageshack.us/img390/3259/untitled39pj.jpg

This pic is using grid and i apply displacement onto it. The white area bulge.
http://img133.imageshack.us/img133/3239/untitled41yx.jpg


Can anyone explain this ? Thanks.

freddie
06-23-2006, 04:23 PM
Set a negativ value in the bump factor, that should fix it.

CiaranM
06-23-2006, 04:59 PM
It looks to me like the white is depressed and black is bulging on the plane bump, just like on the sphere..... You just need to invert the bump strength to get the correct result.

diginime
06-23-2006, 05:28 PM
Ok..This i know. But i want to know that what colour actually affect the bulge? Is it white create depress and black create bulge? Then what about displacement?

This is the plane bump i render from top view, the black area seems like depressing...
http://img521.imageshack.us/img521/4196/untitled16rt.jpg

visualboo
06-23-2006, 08:52 PM
Bump in XSI is the worst.

Search the forum for zbump. It's a great shader Ben wrote that I use a million times a day.

Chris-TC
06-23-2006, 10:01 PM
The bump mapping in XSI is simply inverted. If you want the white areas to be raised use a negative bump factor.

visualboo
06-24-2006, 02:15 AM
Each his own. But thats not the only issue.

diginime
06-24-2006, 04:49 AM
I just searched at the XSI guides there about bump and i found that the white area make depress and the black make bulge... Then i try displacement, it's different, white area make bulge and black make depress. Sometimes in bump the white area seems like bulging...I'm getting confuse..

diginime
06-25-2006, 04:21 AM
Bump in XSI is the worst.

Search the forum for zbump. It's a great shader Ben wrote that I use a million times a day.
I had try out the Zbump. It seems like similar to Bumpmap Generator, just i found that the white area are bulging with the positive factor. If use Bumpmap Generator, the factor have to be negative value to achieve this. Anyway, Zbump seems to be like easier.

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06-25-2006, 04:21 AM
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