Being a heavy user of Poser 7 and Poseray, it is almost unavoidable that I 
have to come up with a number of (new) comments, partly deriving from the 
use of Poser 7. I post them here, together with an example image, so that 
everybody interested may learn from them and may add things that I have 
forgotten.

1) Bump mapping:  When applying an image map as bump map to, e.g. a cloth, 
one may often want to scale down (or up) the bump map in order to obtain the 
desired effect. In Poser, this is done by changing the U_Scale and V_Scale 
of the bump image map in the Material Room. However, this scaling is not 
taken on by Poseray and, to obtain the desired effect, one needs to add 
manually a scale parameter to the map in the exported xxx_POV_mat.inc file.



2) Bump_size: By default, Poser defines a white background parameter in the 
Material Room for all the used image maps. This has unexpected consequences 
when using a bump map, even if the used image has traditionally black as 
background and white as foreground. Poseray translates the bump sizes into 
negative values which may disconcert at first, but renders correctly in 
POV-Ray. However, the values are very high (e.g. -20, or -50) for some 
reason (even if the bump strength in Poser is set to 1.0) and they may have 
to be changed to more conventional values manually.



3) Procedural textures: Procedural textures in Poser are only shown in 
Poseray (and exported to POV-Ray) as pigments and finishes. This is 
understandable as the procedural parameters used by Poser may not be easily 
translated into POV-Ray code. When using procedural textures in Poser, best 
is to find an equivalent POV-Ray texture and use that instead.



4) G2 hair: Poser 7 introduced G2 figures and also G2 conforming hair. For 
many reasons G2 hair is more realistic than the conforming hair in Poser 6. 
However, when exported to POV-Ray through Poseray, the result is rather 
disappointing. I discovered now why this is so. G2 hair uses a bump map for 
displacement mapping. Why for displacement is debatable as the hair mesh is 
fine but not particularly so. Better is to use the map as a bump map. The 
results are much better. However, there is a problem with G2 conforming hair 
and Poseray. First, the hair geometry (in the example I used at least) has 
its morphs centered on the neck body part of the hair figure. In Poseray the 
neck of the human figure AND the neck of the hair figure are translated into 
one single mesh geometry group. Second, and as a consequence probably, the 
displacement map for the hair group is not loaded. While the material maps 
for the hair are properly loaded, the bump map is not. When adding the 
proper bump map in Poseray and exporting to POV-Ray, the results are 
excellent.



The attached image resumes the comments above and shows how the figure and 
the hair should be.





Thomas

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