[TUT] Bump mapping for SH4 in GFX Suites

[skwasjer]

Hi Danlisa, thanks for the tutorial, good job.

Some remarks:
- the alpha channel of the AO texture is actually a 'specular mask'. You can see evidence of this in the SH4-shaders (I've investigated this for the upcoming S3D icw. texture support). The specular mask however can also be in the alpha channel of the base texture (if this doesn't need the alpha channel!), and this difference is indicated in the UnifiedRenderControler where you have the option UseSpecularFromDiffuse (yes/no), where no implies to use it from the AO-map.

Here's another good specular map tutorial: http://www.wonderhowto.com/how-to/vi...-max-8-196435/

- the green/blue channels are swapped because the game also has two axis swapped (YZ), or at least, that's what I guess. It makes more sense to swap the values in the textures, then do it in the shader at the expense of cpu-cycles.

I think it's a decent way to get bumpmaps for low poly models, but it is not as good as generated normal maps from high poly models (although this may not give the desired result from the get-go either). That said, we don't have access to alot of older (SH3?) high poly models, so it's good to know this method.


[edit] As an aside to those interested in this subject, take a look at this thread I made a year ago:

http://www.subsim.com/radioroom/showthread.php?t=126436

It's not a tutorial, but does describe all the different maps and shows them applied to the Yamato in different stages.