RE: [Algorithms] packing textures : normals & lightmaps

[Ced <je...@cl...>]

You can have a look to this paper

http://mirror.ati.com/developer/NormalMapCompression.pdf

The DXT5 tricks is explained in the ShaderX book (do not remember if it was=
=20
the first or second edition)

Hope i could help

C=E9dric

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At 23:54 18/12/2003, you wrote:

>At 02:36 PM 12/18/2003 -0800, Jon Watte wrote:
>>Another way to do normal maps is to store a grayscale height field (much
>>like a displacement map) and take partial derivatives at runtime
>
>Yeah, that's pretty sexy, but I'm on PS1.1 =3D no go.
>
>At 04:13 PM 12/18/2003 -0500, Francis Boivin wrote:
>>As far as normal maps are concerned, the "trick" with DXT5 would be to
>>encode either X, Y or Z in the alpha channel
>
>Have you done this?  Do you have screen shots?  Does it look=20
>reasonable?  I would think the DXTC chunking artifacts would still give it=
=20
>a very bad "scaly" look.  Try it on a sphere, that tends to show the worst=
=20
>anomalies.
>
>
>----------------------------------------------------
>Charles Bloom    email "cb"    http://www.cbloom.com
>
>
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