Viewing .obj files in Partiview

OBJ is a 3d model format, and the only one (that I know) is taken as input by Partiview.

Often you have a model in some other format, such as VRML2, and you want to view it in Partiview. You use a third-party tool such as PolyTrans or Crossroads to convert it to OBJ format, but this doesnt get viewed by Partiview directly. One reason for this is that Partiview does not support the full OBJ format - it supports polygons and some texturing.

Viewing a OBJ file in Partiview, sans color

First, we view a obj file in the plainest form possible. Suppose we use mannequin.obj from Xiao Hu's site.

Create a file hux.cf with 

  waveobj -static mannequin.obj
  eval alpha 0.8

(The second line makes the model transparent; saying "eval alpha 1" makes it opaque.)

And then say (assuming partiview and mannequin.obj and hux.cf are in your path) 

  partiview hux.cf

This results in a nice model you can spin around, etc. (right)

Viewing a OBJ file in Partiview, with one color

It is also quite easy to add a single color to this: add one more line to your hux.cf file, so that it now reads: 

  waveobj -static mannequin.obj
  eval alpha 0.8
  eval color const 0.7 0.4 0.2

Of course, 0.7 0.4 0.2 should be replaced by RGB values (between 0 and 1) for what you want. Typing "partiview hux.cf" as before results in a prettier picture.

Viewing a OBJ file in Partiview, with a texture

(From Stuart Levy, 7/16/04) "The only way "waveobj" can deal with multiple colors only via texturing. That is, you could say 

          texture -M 1  blah.sgi
          waveobj -t 1  flump.obj

and have flump.obj include "vt" texture coordinates. If you made a texture image with patches of solid color, and assigned texture coordinates to lie within one or another patch, you could get colored faces.

But otherwise no. You can't have a .mtl material library, and assign materials to subsets of faces, as the full-fledged Wavefront .obj format would allow."

Here's an example, using bluemarble.sgi and temple.obj from my favorite OBJ archive 

   texture -M 1 bluemarble.sgi
   waveobj -texture 1 temple.obj
   eval alpha 0.8

There is hope, however. Stuart goes on about an interesting undocumented feature :

"mayaobj", which also reads .obj files, does allow assigning material properties (colors, shininess factors, textures, etc.) to groups of faces. But it was written to work with Maya, so rather than reading .mtl libraries it digs through Maya ASCII (.ma) files...

The format of OBJ files