No NURBS surface rendering ?

M

Max_B

0
No NURBS surface rendering ?

hi,
I just registered here and posted in another thread about Rhino.
While evaluating C3d, I just realized that imported nurbs surfaces are not rendered, not even displayed in C3d view. They are in the objects browser.

I understand that C3d is a polygon modeler. But from the different reviews I read and also because it is able to draw nurbs curves, I though it would render nurbs surfaces.

Is it me missing something or is it that way: no nurbs render?

Then this is on the wish list. NURBS are mandatory for some kind of design. Ability to import them, mix with polygon/subdivision objects and render the whole thing is a must.
 
Max_B said:
hi,
I understand that C3d is a polygon modeler. But from the different reviews I read and also because it is able to draw nurbs curves, I though it would render nurbs surfaces.

Is it me missing something or is it that way: no nurbs render?
Click to expand...

No nurb surfaces just sds. However, nurbs are supported in the fbx file format but I have never tried importing a nurbs object using fbx into C3D. Worth a try though.
 
Last edited:
fused said:
However, nurbs are supported in the fbx file format but I have never tried importing a nurbs object using fbx into C3D. Worth a try though.
Click to expand...
That's precisely what i did.
Here is a capture of a test file in Maya, with two nurbs objects (sphere and torus) and one polygonal sphere:
maya_test.png

This is what i got in C3d:
C3d_import.png


If you care testing here is the FBX: http://ac-mb.info/test/tore_nurbs_ma.fbx

Too bad.
 
Cheetah doesn't do NURBS and I suspect it never will. NURBS are still useful, mainly in engineering applications, but the advent of subdivision surface modeling is pretty much the entire reason behind the explosion of alternative 3D tools AND the huge improvements in character modeling in the last ten years. (SDS was invented by Pixar precisely because NURBS sucked for organic modeling.)

Building NURBS tools is horrendously complex (from a programming and UI point of view). Just read the instructions (for any 3d program) on how to "stitch" two surfaces together and your eyes will glaze over. (And if you follow the instructions you may well find the whole thing blows up in your face.)
 
podperson said:
Cheetah doesn't do NURBS and I suspect it never will. NURBS are still useful, mainly in engineering applications, but the advent of subdivision surface modeling is pretty much the entire reason behind the explosion of alternative 3D tools AND the huge improvements in character modeling in the last ten years. (SDS was invented by Pixar precisely because NURBS sucked for organic modeling.)

Building NURBS tools is horrendously complex (from a programming and UI point of view). Just read the instructions (for any 3d program) on how to "stitch" two surfaces together and your eyes will glaze over. (And if you follow the instructions you may well find the whole thing blows up in your face.)
Click to expand...
I agree with your point. I was not asking for C3d to model nurbs. Rhino do this already, soon to OS X.
I just wish it could import and render nurbs objects (surfaces).
 
Understood.

Rendering NURBS would require implementing NURBS engine (just not the UI for it), so you'll need to convert the NURBS into a Mesh in the modeling program before exporting to C3D. Since a large part of NURBS implementation is the UI stuff (individual patches are mathematically straightforward) I guess it's not inconceivable that one day C3D might be able to render NURBS models.
 
podperson said:
Since a large part of NURBS implementation is the UI stuff (individual patches are mathematically straightforward) I guess it's not inconceivable that one day C3D might be able to render NURBS models.
Click to expand...
And given that there is a solid open source base, on which Rhino itself is build, we may hope this is not too far away.
After all, recent major announces from Modo team were Sketchup and Rhino translators.
 
podperson said:
Building NURBS tools is horrendously complex (from a programming and UI point of view). Just read the instructions (for any 3d program) on how to "stitch" two surfaces together and your eyes will glaze over. (And if you follow the instructions you may well find the whole thing blows up in your face.)
Click to expand...

Exactly! (read my other post about Solidworks!)

SDS modelling is a lot easier to use, once you understand the principles.
 
Hi Max_B,
thanks for the FBX file. I'm searching for such a file since quite some time. Until now I only found FBX files with polygons.

The FBX SDK can convert NURBS to polygon meshes. But until now I don't use this functionality but since I have an example file now I should have an look into these SDK functions.

So while it won't be possible to load real NURBS in the foreseeable future it should be at least possible to import tessellated meshes.

Bye,
Martin
 
Martin,
thanks for the feedback.
I'm glad you are considering adding automatic tessellation for imported nurbs.

I also made today a test OBJ file from Rhino with a torus nurbs surface (FBX exporter is not ported to OS X yet). This one does not even shows up in C3D objects browser.
While it looks like you prefer working on FBX files, I attach it there in case it could be useful.
 

Attachments

  • tore.obj.zip
    1.5 KB · Views: 271
Max_B said:
I also made today a test OBJ file from Rhino with a torus nurbs surface (FBX exporter is not ported to OS X yet). This one does not even shows up in C3D objects browser.
Click to expand...

Yes, and you should now knowing why. :)
But you can receive a mesh on the fly exporting to polymesh and polylines :cool:

With kindest regards
Frank
 

Attachments

  • RhinooObjMesh.jpeg
    RhinooObjMesh.jpeg
    79.3 KB · Views: 234
  • tore2.obj.zip
    73.9 KB · Views: 256
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