Is it possible to draw an .OBJ model to an offscreen buffer?

I'd like to be able to pick distinct .OBJ models in 3D using a color buffer, as in the example http://wiki.processing.org/w/Picking_with_a_color_buffer , but with imported .OBJ geometry instead of boxes.

I have been trying to work out how to do backface culling in p5. I'm using the objloader library to import geometry, so I would love tips/experience particularly from people who've worked with that library. Also this wiki page says that processing can do that internally, but doesn't tell how ( http://wiki.processing.org/w/Backface_culling) any ideas?

The following snippet from the google code site looks like I should just be able to un-comment that section to enable backface culling within the library, but I can't get it to work.

1. // turn on backface culling
2. gl.glFrontFace(GL.GL_CCW);
3.  
4. gl.glPolygonMode(GL.GL_FRONT, GL.GL_FILL);
5.  
6. // gl.glPolygonMode(GL.GL_BACK, GL.GL_GLPOINTS);
   
7. // gl.glEnable(GL.GL_CULL_FACE);
8. //
   
9. // gl.glCullFace(GL.GL_BACK);
   

(from line 164: http://code.google.com/p/saitoobjloader/source/browse/trunk/OBJ_Loader/src/saito/objloader/Segment.java#164)

I tried expanding the library's .JAR file, uncommenting the section and turning it back into a JAR file, but that still shows backfaces (you can see them when the faces are rendered with some transparency) and I haven't seen a change in the FPS.

I'm working to reduce the polys in the imported model (it's a simplified model of a city, so that takes awhile) and other methods of increasing FPS in an interactive 3D model could be useful.