Normal Mapping

[xtu6io666]

Normal Mapping系一個mass production幾正既方法, 但系邊位只能保持low res polygon既型態, 系咪真系"可以遠觀而不可x玩"???

[h2o]

用 displacement 做番d details, 再修補下........ 不過可以用呢個方法 , 又要 render 得快, 唔閃, 相信只有 renderman 先得!

[chatho]

剛剛搵到o的資料俾大家 :

In 3D computer graphics, normal mapping is a more advanced version of bump mapping. While bump mapping uses grayscale variance, normal mapping uses the three color channels (RGB) for the three normal axis (XYZ). Like bump mapping, it is used to add details to shading without using more polygons.
How it Works: To calculate the light on a surface, the vector for an incoming light source is dotted with the vector normal to that surface, and the result is the intensity of the light on that surface. Imagine a polygonal model of a sphere - you can only approximate the shape of the sphere, and how good your approxmation looks depends upon the number of polygons you use. Each triangle on the face of the sphere will have a specific light value, and this light value will be uniform across that entire triangle - giving the sphere a rather jagged look. With normal mapping, instead of just one normal vector for each triangle, there's a multitude of them, and thus the shading on the sphere looks much more realistic - from a a distance, it doesn't seem to be made up of individual triangles.

quoted from www.fact-index.com

additional link:
http://www.monitorstudios.com/bcloward/tutorials_normal_maps1.html
http://sv3.3dbuzz.com/vbforum/showthread.php?s=&threadid=77037