Hi Michael,

Opening the .obj, center the camera, F9 (rendering) ... I didn't edit anything else

And render in C4D10 with no specular looks like this:

Hi PaQ,

> Opening the .obj, center the camera, F9 (rendering) ... I didn't edit anything else

Well, looks like mach banding artifacts.

Is there any setting in materials to do full Phong shading?

Maybe it's not doing very careful interpolation of the normal or something like that.

As you can see in the Cinema4D renders, if the vertex normals are treated carefully by the renderer so that each individual pixel ends up getting shaded by a good normal, it makes for nice results even with a pretty rough mesh.

Maybe it is not as common to do that as I had thought though.

- Michael

Hi PaQ, quick question - can you switch to an orthographic/parallel type camera and then give it a try?

Does the render look different in that case?

- Michael

Hi Michael,

There are no shading option available in modo, there is a 'smooting angle option' in degree, to control the surface normal, but the vertex normal channel overwrite this setting anyway.
Same result whatever the camera mode (ortho or perspective)

Hi PaQ, well I guess for now if rendering in Modo you will need to force some dicing of long polygons into smaller pieces to reduce those artifacts.

It seems like it would be a good thing to report to them, because it doesn't really have to be that way, as you can see from the Cinema4D examples.

That kind of mach banding artifact usually happens in Gouraud real-time shading because in that shading method the normals are only evaluated against the full light sources just at the polygon's vertices, and then those colors blended throughout the polygon.

It kind of looks like you're getting that same kind of effect in the full render...

- Michael

I did some testing by building a cone in Modo with approx. same vert. count, and did one with double the verts. and it was
pretty smooth. Two cones on the right were created in modo. Similar faceting on the lower poly version.

Hi danperk, yes that is interesting that the same artifacts are present in natively created Modo geometry as well.

This kind of artifact gets reduced when polygons get smaller in size on the screen, so increasing the vertex count around the circular direction is one way to do that, but also doing a few vertical divisions is another way.

But you really should not need to go to such a high density to avoid these artifacts in a full render, it would be better if the full render did a more proper vertex normal interpolation so that you could get nice results with lower polygon counts.

Taking some shortcuts in interpolation can help to speed things up, maybe this is an area where some quality was sacrificed intentionally for a speed gain, but it would be good to have an option to control that if that was the case.

- Michael

A strait cylinder created in Modo seems to be pretty smooth beyond 12 sides, so it seems to be
the cones angle where the render has problems.

Maybe some combination of the cone's angle making some greater variation in shading, along with the cone's taper causing the polygons to have different widths at the bottom versus the top. That may have some kind of subtle effect on the stuff being interpolated across the polygon.

- Michael

Once again I fear the render problems is due to the codebase within Lightwave.

Since Modo was lifted from Lightwave, it has inherited the same problems - incorrect support for supplied normal information.


As Michael proved using Cinema 4D, if the normals are handled correctly, the objects should look exactly the way they do in MoI.
(And that's the reason why I went broke purchasing C4D since it was the best at importing MoI objects...)

I plan on showing any artifacts and discussion threads like this in the CORE forums to try and make sure CORE will be as good as C4D in handling MoI imports.

I eventually want to let C4D and stick exclusively with LW but I can't if it's not going to provide similar results.


-Will