Support of primitives like Spheres or Cylinders possible?

[B.Y.O.B.]

Hi,

I wanted to ask if it was possible to export, say, UVSpheres from Blender to LuxRender as a Lux Sphere (you know, the primitive that's defined by it's midpoint and radius) if there's something like "export as sphere primitive" ticked.
Am I right that this would avoid the terminator issue raytracing suffers from?

Of course it would only be senseful for unmodified UVSpheres (apart from transformations).

[J the Ninja]

Hi,

I wanted to ask if it was possible to export, say, UVSpheres from Blender to LuxRender as a Lux Sphere (you know, the primitive that's defined by it's midpoint and radius) if there's something like "export as sphere primitive" ticked.
Am I right that this would avoid the terminator issue raytracing suffers from?

Of course it would only be senseful for unmodified UVSpheres (apart from transformations).

Yeah, it would avoid the terminator artifact since it's a geometrically defined sphere. I think it might be possible to mess with the external mesh proxy code to export some other shape, but I haven't looked at it too closely.

[B.Y.O.B.]

The best would be if Blender would provide an indicator for if a mesh is changed, so you can check if the UVSphere is a "new" one.
Then, if the "export als primitive" checkbox is checked, the midpoint and the radius had to be found and exported.

I don't know how complicated that would be (also with an eye on translations like resizing...) as I have no idea of the stuff Blender provides here.

[A-man]

I think it should be up to the user to make sure the sphere is not modified. All it should need is the origin (x,y,z) and a radius (taken from the object's 'scale'). It could be a cube or bunny for all the exporter cares.

[B.Y.O.B.]

Apparently the Blendigo exporter (Blender -> Indigo Renderer) has this feature: a sphere primitive is exported if the object name ends with ".sphere".
http://www.indigorenderer.com/forum/vie ... 90#p115490

[A-man]

Hey that's a good idea! It should also be able to support other primitives like cylinder and cone and whatnot with the appropriate suffixes using that method.

[B.Y.O.B.]

I'm not sure though if either the mesh name or the object name should be used... but that's a decision for the programmer, I guess.

[SATtva]

Unlike a sphere, which dimensions/transforms can be easily calculated from the mesh's bounding box, cylinder and cone are more tricky. For example, how could you know which side is "up" for the cone?

[J the Ninja]

Unlike a sphere, which dimensions/transforms can be easily calculated from the mesh's bounding box, cylinder and cone are more tricky. For example, how could you know which side is "up" for the cone?

Point the tip to +Z and just use the object's rotate transform to do the rest? That's how Blender's cone primitive spawns anyhow.

[B.Y.O.B.]

Btw. I'd rather have a tickbox in the object tab that says something like "export as x primitive" than that name-stuff from Blendigo.