Hi Phil - well MoI always exports vertex normals in the same way - the normals come from the original NURBS surface that the polygons were generated from.
Smoothing groups support should not really have anything to do with it - when the vertex normals are being used, they should completely define the smoothing appearance of the polygons.
Usually it is either one or the other - either you use smoothing groups and have the vertex normals created by an averaging process of face normals between adjacent polygons in the mesh (only between polygons in the same group though), _OR_ you use stored vertex normals in which case they will be oriented to make a crease where there should be creases and so forth, when you use vertex normals it is in place of using smoothing groups, not something you use in addition to them.
The kind of artifacts that PaQ is showing in several of the posts here definitely look like some kind of problem with vertex normal handling.
I've seen problems that have a similar look as this in some programs that do not use the stored vertex normals and instead calculate them only by averaging face normals. That's not good because that is throwing away the accurate normal that came from the original NURBS surface.
Maybe another possibility is some problem with interpolating the normals?
> Imagine if you have 2 polygons that are connected by a shallow
> angle, they should be separated into 2 groups otherwise they will
> be interpolated and you get shading artifacts.
This part does not make sense to me - when you use the stored vertex normals, all the information for how a polygon should be smoothed is already present in the normals themselves - if 2 faces are supposed to be creased with each other that means they would each have a different vertex normal pointing in different directions, so when the polygons are rendered, each polygon would be using its own normals.
Does Octane maybe not support having 2 faces that share a 3D point location in common but have separate vertex normals for each face rather than having a shared normal as well?
What happens if you just export a box from MoI to Octane with welding turned on, what does that look like?
Also, PaQ can you pick just one single, simple surface that has those artifacts in it when imported into Octane, and then post that here so that we can focus on a good simple example case?
- Michael
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