Bump Mapping

⌘-R in Chief
Posts: 1,276
Joined: 2002.05
Post: #1
What is bump mapping?
Luminary
Posts: 5,143
Joined: 2002.04
Post: #2
A technique for adding detail to a 3D scene via the per-pixel lighting of each rasterized triangle based on the normal at each vertex, the direction of the light, and a height- or normal-map of the triangle's surface at a higher resolution than the underlying geometry.

⌘-R in Chief
Posts: 1,276
Joined: 2002.05
Post: #3
Quote:Originally posted by OneSadCookie
A technique for adding detail to a 3D scene via the per-pixel lighting of each rasterized triangle based on the normal at each vertex, the direction of the light, and a height- or normal-map of the triangle's surface at a higher resolution than the underlying geometry.

Oh ok. BTW, that did make sense
Luminary
Posts: 5,143
Joined: 2002.04
Post: #4
I knew it made sense, I just didn't know if it was going to be any use to someone who didn't know what bump-mapping was.

I wonder if I could have stated it as concisely and precisely whilst making it still more difficult to understand :confused:
Feanor
Unregistered

Post: #5
Quote:Originally posted by OneSadCookie
I knew it made sense, I just didn't know if it was going to be any use to someone who didn't know what bump-mapping was.

I wonder if I could have stated it as concisely and precisely whilst making it still more difficult to understand :confused:

Replace it with the lighting calculation equation or something. Math is the most concise, most difficult to understand way of writing any quantitative procedure.

For the uninitiated, it means making flat surfaces look bumpy, by drawing fake shadows on the surface around where you want bumps to be. Personally, I wasn't aware of the method using the vertices. I'm familiar with the DOT3 method, which using a second texture of the same size as the rgb texture to store the normal to the matching pixel. The bump texture uses the r, g and b values to store x, y and z values for the normal. When you see a bump texture, it always looks freaky because it looks like a false-light version of the original texture, and usually has pinkish and cyanish look to it.

Download the DOT3 sample code from Apple to see an example.

--FÎanor