[Chimera-users] Capping in VRML

[Tom Goddard]

Hi Greg,

  We will be improving ChimeraX export of 3D models, focusing on glTF format for an NIH 3D model repository.  The area of 3D model file formats has forever been a mess with many formats with none of them widely and robustly supported.  I think all of the formats exported by Chimera and ChimeraX (OBJ, glTF, Collada, VRML, X3D, STL, ...) conform to the file format standards, but the import capabilities of even widely used 3D modeling packages (Blender, Cinema4d, Maya, ...) are very shaky.  One of the basic capabilities used heavily by Chimera and ChimeraX and other science applications are "vertex colors" where every vertex of a triangulated surface is given a color.  Many of the scene formats support that (glTF, Collada, VRML, X3D, ...) but most of the readers don't support it.  The generic modeling packages want to use only texture colors.  But there are many other features of the file formats that readers don't support or optional features that the readers require in order to function correctly.

  At any rate, we will be improving the ability of ChimeraX to export models for use in generic (ie non-biology) 3D modeling packages -- basically try to accommodate the many quirks of the file readers.  We are not planning to work on VRML -- that very old format does not seem favored by the 3d modeling community although much legacy software uses it.  It is a sad situation in the 3D modeling community that the file formats have such poor support.  It almost seems that many of the software packages deliberately don't want to interoperate with other (competitor's) software.

	Tom


> On Oct 31, 2020, at 3:01 PM, Greg Williams <gregoryw at comcast.net> wrote:
> 
> Oh dear…
> 
> It’s distressing that you’ve lost the vrml export. That’s the only workable format I’ve been able to get out of Chimera and into Cinema 4D. 
> 
> There is no export in Chimera X that works well with Cinema 4D. I was able to export an obj file of 2bbv. The exported file was 300 mB! I was able to open it in C4D, but there was no content in the open file.
> 
> I’ll do the best I can with the older Chimera. I’ve been hoping for several years that you would develop a good export function for modern commercial 3d graphics programs. I guess that’s not going to happen, and now I’ve lost VRML. Oh well….
> 
> Thanks for the quick response. 
> 
> Greg
> 
> 
> 
>> On Oct 31, 2020, at 1:22 PM, Elaine Meng <meng at cgl.ucsf.edu> wrote:
>> 
>> Hi Greg,
>> There's no setting like that (and Chimera only uses one material) so I believe it is simply a limitation or bug.  I'll make a ticket for this problem, but note that our group's resources are mainly directed toward ChimeraX these days.
>> 
>> Can Cinema 4D read any of the other Chimera export formats?
>> <https://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/export.html>
>> 
>> ChimeraX can save glTF, X3D, and some other 3D-object formats, but not currently VRML.  If one of those can be used as input to Cinema 4D, you might want to try ChimeraX instead.
>> <http://rbvi.ucsf.edu/chimerax/docs/user/commands/save.html#formats>
>> 
>> ChimeraX ribbons are calculated differently than Chimera, and there is a tube (curved cylinder) option for helices.  There are some ribbon choices in the Presets menu of ChimeraX, for those who aren't yet experienced with the commands and their options, and there are a few example images here:
>> <https://www.rbvi.ucsf.edu/chimerax/features.html#presets>
>> 
>> I hope this helps,
>> Elaine
>> -----
>> Elaine C. Meng, Ph.D.                       
>> UCSF Chimera(X) team
>> Department of Pharmaceutical Chemistry
>> University of California, San Francisco
>> 
>>> On Oct 31, 2020, at 11:02 AM, Greg Williams <gregoryw at comcast.net> wrote:
>>> 
>>> When I export a vrml file to process in my Cinema 4D application, the ends of the helices, coils and sheets are capped at the ends with a material that is different then the material I use to color the secondary structure features. In Cinema 4D, I have to change every capped end individually. Where do I change the vrml export settings so that the individual objects are capped with the right material?
>>> 
>>> Thanks!
>> 
> 
> 
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