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normal map vs. bump map

Posted: Wed Nov 22, 2006 6:10 pm
by tikal26
I am wondering what is the difference between normal and black and white bump mapping. Is one faster than the other and which one do you prefer to use? Why?


Edit: I guess I want to know why you will use over the other one? What are the advantages?

Posted: Wed Nov 22, 2006 6:13 pm
by aitraaz
not quite sure i get the question...Here's bump vs. normal mapping:

http://en.wikipedia.org/wiki/Normal_mapping

Posted: Mon Dec 18, 2006 10:39 pm
by w i l l
Meaning what is the difference in the resulting render from using a normal or bump map.

Is there a good normal map generator? Is there a plugin for Photoshop?

Posted: Mon Dec 18, 2006 11:03 pm
by DrMerman
Hey guys.

Nvidia produce what is widely considered to be the most popular normal map generator :

http://developer.nvidia.com/object/phot ... ugins.html

As to which is better, although neither actually modifies the geometry of an object, normal maps tend to provide a more accurate solution. This is because there can be a lot more surface information held in a colour image (normal map) as opposed to in a black and white image (bump map.)

Although saying that, it really comes down to your individual scenes, and what best suits the given situation.

Cheers,
Dr Merman

Posted: Sat Dec 23, 2006 11:45 pm
by Eurofiles
Your answer:

Bump maps give information about the depth of a surface. So they can be used to give a sense of increased detail in an image. Because they are greyscale format, they can only go so far in providing information about the surface of an object it's applied to. For each level of grey, a different depth is assigned.

Normal maps contain information about not only depth of a pixel, but the angle of orientation (facing angle for each pixel), hence contianing greater bit depth. If you notice, bump maps contain color information, allowing a lot more information to be stored in the map, where each color represents a different depth and angle of the geometry it is applied against. The end result is that light that bounces off the surface takes into consideration the pseudo orientation of the pixel and bounces the light in the correct manner.

That's the understanding I have.

Posted: Sat Dec 23, 2006 11:51 pm
by w i l l
Thanks for that. Good link Dr!

Posted: Sun Dec 24, 2006 12:05 am
by MarkM
This might be some help as well :wink:

http://www.zarria.net/nrmphoto/nrmphoto.html

Posted: Sun Dec 24, 2006 1:02 am
by w i l l
Yeah I saw that link before, but couln't be bothered with it as it requires moving from this seat. Cheers Mark.