[Chimera-users] VRML rendering options?

Greg Couch gregc at cgl.ucsf.edu
Fri Jan 18 09:56:38 PST 2008

On Fri, 18 Jan 2008, Nils Becker wrote:

> Hi,
> I have been using Chimera for a while and find it great software. Now I
> am trying to include my own VRML models and show them together with PDB
> data. I succeeded in opening an externally generated VRML 2.0 file.
> Since the VRML file contains colored boxes, the standard smooth
> rendering is not appropriate.
> Is there a way to influence the rendering style?
> Also, is there a way to switch on a fixed transparency (alpha value) for
> the whole VRML model, on a per-model basis?
> Any help would be appreciated!
> Cheers, Nils

First transparency:

Currently, the per-model transparency is not exposed to Python, so it 
can't be modified by the user interface.  I will look into how hard that 
would be to fix.  A better solution would be to add support for VRML3, 
a.k.a., X3D, ColorRGBA nodes.

Now rendering styles:

VRML lets you specify per-vertex normals for smooth rendering or per-face 
normals for faceted rendering.  So in an IndexedFaceSet, you would set the 
normalPerVertex field to be FALSE and give a normal for every face.  For 
VRML Boxes, you get faceted rendering only (because a smooth rendering 
would be a (squashed) Sphere).  The VRML specification can be found at 

 	Hope this helps,

 	Greg Couch
 	UCSF Computer Graphics Lab

More information about the Chimera-users mailing list