Hello,

I am currently trying find an optimized method for quickly producing visualizations of furniture directly from MOI using Keyshot. The problem is that Keyshot does not seem to be able to read geometry from 3dm files if is not shaded, and the MOI 3dm output doesn not appear to contain this data. Rhino versions of the same file work when saved using the Shaded view option.

Is there a workaround for this issue? or even better, is there a fix planned for the 3dm file output to make geometry visible to Keyshot.

greetings,
Maxim

Hi Maxim, this seems to be a change in behavior in Keyshot?

It looks like they no longer read the actual NURBS data stored in the 3DM file and will only process polygon mesh data from the 3DM file. Rhino stores polygon mesh data attached to NURBS data when it does a shaded view, because Rhino's mesher is very slow so it tries to avoid recalculating it when it loads the file later on.

MoI has a fast display mesher, so MoI does not attempt to store the display meshes as additional data into the file since it increases file size by quite a bit.

You may want to contact Keyshot's support and ask why they have made this change and why they aren't able to process the NURBS data directly anymore.

At any rate, you can solve the problem by using OBJ format to export from MoI into KeyShot, rather than 3DM format. 3DM format will not work with MoI-generated 3DM files if they only try to access display mesh data alone, since MoI only stores NURBS data in 3DM files and doesn't try to store polygon mesh data in there as well.


> or even better, is there a fix planned for the 3dm file
> output to make geometry visible to Keyshot.

Well, no fix is really necessary since you can use OBJ format to transfer polygon mesh data from MoI into Keyshot. This will also allow you to adjust the density of the display mesh at export time from MoI.

It would not work very well for MoI to try and store display mesh data in the 3DM file as Rhino does, because MoI's display meshes are created with a different process than export meshes and are meant for the realtime shaded view and not for a full quality render. That's different than Rhino, since Rhino uses the same mesh mechanism for both export and for display meshes.

Since MoI has a different meshing process for realtime display versus export, it would not really be a great idea to store the realtime display mesh in the 3DM file such that it would be used by a rendering program for a full render, the export mesh as generated by OBJ export is more carefully constructed than the realtime display mesh and it's better to use the export mesh for a full render.

- Michael

Hi maxim, so another way I could describe it is - if you want to transfer polygon mesh data out from MoI into a rendering program, then 3DM format is not a good way to do that. It's better to instead use OBJ format to transfer polygon data between programs, that's a much more common format to use for that particular kind of data.

MoI will only write NURBS data to 3DM files and does not store polygon data in them.

- Michael

Hi Maxim, also another reason why MoI does not try to store render mesh data in a 3DM file is that there are various limitations on it, like no n-gons, no ability to weld vertices but have distinct UV and normals for 2 faces that share a common vertex, and no way to have multiple materials on different faces within a single solid.

Using OBJ format does not have any of these limitations, that's another reason why it's better to send mesh data to a renderer by using OBJ format rather than attempting to store render mesh data inside a 3DM file.

- Michael

Hi Michael,
Hi Maxim,
As far as I can remember KeyShot(HyperShot) never really handle .3dm NURBS data very well it always relied on the mesh data in Rhino files.
Another good export option is STEP, I found KeyShot converts STEP data pretty good.

Cheers

Hi Danny - re: STEP - one issue with that is that material (style) assignments on different faces within the same solid will not go through with STEP, but it will with OBJ format. OBJ is just a more commonly used way to transfer render data...

- Michael

Hi Michael,

You're right about the individual faces you loose that with STEP or KeyShot used to, I haven't been keeping up with it lately so I don't know if anything has changed.
I mention STEP because of the two stage result; save as STEP, import into KeyShot, where as .obj is; save as, manipulate mesh, then import into KeyShot. I know some engineers that don't want to mess around with meshes, they just want a quick picture and KeySot's meshing of STEP files is pretty smooth.

Cheers