Hello,

I am looking into expanding my utility PoseRay into a more general 
Wavefront OBJ to POV-Ray code converter. Right now it can handle many 
types of OBJ files with success but I would like to make it more useful.

I was thinking of creating a few options to make it compatible with most 
ASCII OBJ files by adding a few options such as

-better geometry scaling and translation
-flip x,y or z axis coordinates
-flip normals

I have the Wavefront OBJ spec but I know that every 3D program has its 
own way of exporting OBJ files (if it can). Does anyone know of more 
options that will make my utility convert more OBJ files created by 3D 
programs?

thanks for your attention,

FlyerX
PoseRay home page.
http://user.txcyber.com/~sgalls/

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Wasn't it flyerx who wrote:
>Hello,
>
>I am looking into expanding my utility PoseRay into a more general 
>Wavefront OBJ to POV-Ray code converter. Right now it can handle many 
>types of OBJ files with success but I would like to make it more useful.
>
>I was thinking of creating a few options to make it compatible with most 
>ASCII OBJ files by adding a few options such as
>
>-better geometry scaling and translation
>-flip x,y or z axis coordinates
>-flip normals
>
>I have the Wavefront OBJ spec but I know that every 3D program has its 
>own way of exporting OBJ files (if it can). Does anyone know of more 
>options that will make my utility convert more OBJ files created by 3D 
>programs?

Not all 3D programs support the full set of Wavefront features (this is
particularly true for format convertors that are attempting to create
OBJ files from simpler formats) so you may find that some OBJ files
don't have:-
        Normals
        UV Coordinates
        Materials
        Regions

The UV coordinates may be inverted horizontally or vertically.

The points may use right or left handed coordinate systems, so you may
like to switch Y and Z.

Some OBJ files may have their "winding order" reversed (i.e. the faces
can be described in clockwise or anticlockwise order).

The texture coordinates may not be compressed. (I think that means that
the vt values may not necessarily be in the range 0 to 1).

The line separator may be CR-LF (PC format) or just CR (Mac format).

I'm sure that there are other things that can be different, because I've
seen some things that claim to be Wavefront OBJ files that I can't seem
to handle sensibly.

-- 
Mike Williams
Gentleman of Leisure

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