Exporting a Scene

A scene in Chimera can be exported with File... Export Scene. Available formats:

POV-Ray - input for the Persistence of Vision Raytracer
RenderMan - RenderMan Interface Bytestream
VRML (only surfaces will be exported)
X3D (see also the command x3dsave)

POV-Ray and RenderMan files are generated by postprocessing an initial X3D file, and as such, may share some of the limitations of X3D. The format conversion programs are included with Chimera (executables x3d2pov and x3d2RM in the same directory as the chimera executable) and can be used outside of Chimera.

Similarly, a more complete VRML scene description can be obtained by exporting X3D, then converting X3D to VRML with XSL technology and X3D-Edit's X3dToVrml97.xslt. VRML files generated this way would share the limitations of X3D.

LIMITATIONS

X3D viewers and browser plugins are available for some platforms. However, X3D is relatively new and continues to evolve. X3D does not support certain aspects of a scene:

clipping planes (global and per-model)
depth cueing
lenses
stereo
Volume Viewer displays in the solid rendering mode
normals on dot and mesh surfaces

These limitations are shared to some extent with the formats generated by postprocessing X3D. Although X3D does not show clipping planes and depth cueing, it can contain annotations describing these features. RenderMan files incorporate such annotations and support clipping planes and depth cueing; otherwise, the limitations are the same as for X3D. POV-Ray files do not incorporate such annotations, so the limitations are the same as for X3D.

VRML export includes only:

solid and mesh MSMS molecular surfaces
Volume Viewer displays in the surface and mesh rendering modes
surfaces created with Multiscale Models
GRASP surfaces

Limitations of surfaces in VRML:

Dot surfaces (MSMS molecular surfaces shown as dots, MS/DMS dot molecular surfaces, and VDW surfaces) cannot be exported as VRML.
VRML does not support variations in transparency within a single surface model; different surface models can have different transparencies, but for a given surface model, the transparency of its least transparent point will be used.
VRML does not support normals on mesh surfaces.

A more complete VRML scene description can be obtained by exporting X3D and converting it to VRML, as mentioned above.

UCSF Computer Graphics Laboratory / August 2005