Thomas de Groot wrote:
> 
> 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.

I may implement scaling into the basic materials in the next version but 
now you can go into the POV-Ray tab and copy the material into the text 
window and edit the bump map UV scaling there as a transformation. The 
copy command is in the POV-Ray tab as insert->materials->copy from basic 
tab.

> 
> 
> 
> 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.

I will look into this. Since I do not have Poser 7 I assumed bump_size 
behaved the same as in Poser 6.  You can scale the imported bump size in 
the Poser scene import options. The default value is what Poser 6 uses.
I noticed some inconsistencies between the bump_size implementation 
using different models and whether the bump map was an image or a 
proprietary BUM file.
> 
> 
> 
> 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.

I agree. Would be nice if Poser could bake and export its procedural 
textures. This and strand hair are features that makes Poser less 
portable to other applications.

> 
> 
> 
> 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.
> 

I will look into this since I have one of those G2 models with hair. 
Maybe I could route the displacement call into the bump map 
automatically. I will add this to the manual in the export to Poser 
tutorial section.


Thank you very much for your feedback.

FlyerX

Post a reply to this message