Hi Morgan, Molecular surfaces produced by the Chimera Actions/Surface/Show menu entry provide atomic resolution detail. For a large structure like a ribosome the VRML file for such a high resolution surface will be large. The surface might have a million triangles, and the file will at least be 30 megabytes. (In fact the molecular surface calculation we use, called MSMS, crashes on some ribosome structures like 1jj2.) Chimera provides lower resolution surfaces with the multi-scale extension (Tools/Multiscale menu). Examples showing some viruses and GroEL are shown on the Chimera image gallery: http://www.cgl.ucsf.edu/chimera/ImageGallery/ You can choose the resolution of the multi-scale surfaces. We don't currently have VRML output for the multi-scale surfaces but that could be added fairly easily. I could look into that. The Chimera volume viewer (Tools/Volumes menu) also uses this same type of surface model. So a VRML export tool could also export electron and light microscope 3D data or crystallographic density maps displayed as isosurfaces. Tom