MC: The technique that we’re using to generate the character models are exactly the same for a PS3 or 360 game. All of our models are being built in z-brush and then we’re applying them to the lower res models. What you’re seeing in the game are normal mapped characters. The thing we need to work out is the lighting systems. The more we continue to tweak, the better it will look. I don’t know what the debates are but we are in fact running full normal maps on everything, not just characters..
They say normal mapping on every things.
I guess it work like this way.....Just a guess
not really know the math abilty of wii gpu , could be wrong.
A simple diffuse bump process
Use CPU to preprocess every vertex,
IN Wii CPU
1. For ervey vertex , read vertex's tangent binormal and normal
Use those vector to convert the Light Vector to tangent space
2. Put the tangent space light vector as a vertex attribute,
like color or something.
put vec3(2,2,2) and vec3(-1,-1,-1) as a vertex attribute, too.
3. pass the new vertex to gpu
In GPU T&L unit
1. Do vertex Transformation, but no lighting,.....
In GPU pixel/Tex unit
(It has multiple texture stage can do some math....)
1.Read a texel vec3"bump" in normal map
2. mul it by vec3(2,2,2) and add vec3(-1,-1,-1)
than you get the normal XYZ in 1~-1 range.
3. Dotproduct Lightvector and Normal you get the light Intensity .
4. Read a texel, vec3"basemap" in normal map
5. Mul intensity with basemap , you get a diffuse bump normal mapping pixel.
Only two texture sampling and one MADD and one Dot product, one MUL
The math is simple enough, maybe it is possible to do it
in fixed function hardware,
The downside is the lightvector does NOT get normalize per pixel.
So the normal mapping quality may not as good as pixel shader,
but it's look good enough for most people.
If they work like this, The CPU has to do a lot of extra work,
may limite total polygon count.....
Wii cpu was not much faster than Xbox1 cpu
And Xbox has VS unit to perform the vertex job.
So, Wii maybe can do normal mapping , but the polygon count will be limited
(lower than no normal mapping game).
