Smoothing Groups: How to?

[Vizioen]

Hi all,

I'm a bit confused about smoothing groups. I understand the concept I guess, but there are so many ways in the geometries to smooth your object that I don't know whats what anymore and I'd like some clarification.

For instance I have this cylinder here with chamfered edges and 1 segment on the cap. There's the option in the cylinder to smooth it, there's also the option in the chamfer to smooth the corners or the entire object. I guess the chamfer overrides the smoothing of the cylinder.

1. Viewport


2. Cylinder smooth; chamfer: smooth entire object. You can see a clear line where the cap segment is.


3. Cylinder smooth; chamfer: smooth chamfer edges only. You can see a line where the chamfer ends.


Is it at all possible to smooth the entire object? Putting a smooth modifier with auto doesn't help. The only way I see it disappear is if I remove the Cap segment.


If I put another edge cap then the sharp edge just moves to the loop closest to the chamfer.

[Vizioen]

HJi all,

I'm a bit confused about smoothing groups. I understand the concept I guess, but there are so many ways in the geometries to smooth your object that I don't know whats what anymore and I'd like some clarification.

For instance I have this cylinder here with chamfered edges and 1 segment on the cap. There's the option in the cylinder to smooth it, there's also the option in the chamfer to smooth the corners or the entire object. I guess the chamfer overrides the smoothing of the cylinder.

1. Viewport
[ATTACH=CONFIG]29376[/ATTACH]

2. Cylinder smooth; chamfer: smooth entire object. You can see a clear line where the cap segment is.
[ATTACH=CONFIG]29377[/ATTACH]

3. Cylinder smooth; chamfer: smooth chamfer edges only. You can see a line where the chamfer ends.
[ATTACH=CONFIG]29378[/ATTACH]

Is it at all possible to smooth the entire object? Putting a smooth modifier with auto doesn't help. The only way I see it disappear is if I remove the Cap segment.
[ATTACH=CONFIG]29379[/ATTACH]

If I put another edge cap then the sharp edge just moves to the loop closest to the chamfer.

I've tried with another kind of geometry and this time the sharp edge doesn't even correspond to the geometry. Totally confused now.

[Pixelcon]

You don't have a round edges map in the bump slot right?

[Vizioen]

You don't have a round edges map in the bump slot right?

No this is a very simple material:
- black diffuse
- 200 reflect
- 0.65 Glossiness
- 20 IOR
- GGX BRDF
- Anisotropy -0.5

I've had the same thing with a golden material some time ago too.

Edit:

I just did a test. Started with a glossy black plastic, which I gradually changed to the material that was showing the seam (everytime I changed a setting I rendered). Everything worked fine but it seems that adding the anisotropy caused the issues in this example. But as I recall I had this problem too with a material that didn't have any anisotropy.

WITHOUT ANI:


WITH ANI:

[Pixelcon]

Can you try and re-UV map the object (perhaps even with unwrapping) to see if it fixes the ani problem? I recall Neil Blevins having an issue where default max objects wouldn't render properly when anisotropy was present...

[Vizioen]

Can you try and re-UV map the object (perhaps even with unwrapping) to see if it fixes the ani problem? I recall Neil Blevins having an issue where default max objects wouldn't render properly when anisotropy was present...

I've did a quick and dirty unwrap, also tried a simple box map, both with the same results.



When I put the material on a regular cylinder, it renders normal. But when I put a chamfer modifier (quad) or when I chamfer it within the poly (either quad or regular), it yields the same results as before. So must be something to do with the chamfer?

[Pixelcon]

Well I'm out of ideas...

[Vizioen]

Well I'm out of ideas...

If YOU are all out of ideas, we' re pretty much doomed...

So short recap: chamfer + anisotropy = visible seam? It might be that I don't know how to do a proper smoothing, that was my initial concern.

[Pixelcon]

This might shed some light on it. As I thought, the top anisotropy can't be resolved unless you create the spiral effect...maybe

http://www.neilblevins.com/cg_educat...iso_ref_cg.htm

[Vizioen]

This might shed some light on it. As I thought, the top anisotropy can't be resolved unless you create the spiral effect...maybe

http://www.neilblevins.com/cg_educat...iso_ref_cg.htm

Thanks for the article James, I've read it a while back. I'm not quite sure that's the case here, might be, because it doesn't explain why it works when the cylinder isn't chamfered or doesn't have an extra cap segment.

With ANI + Chamfer + NO extra cap segment. (no extra mapping either just default cylinder with mapping coordinates ticked)

[benb32]

Know it's from a different section (scanned materials), but this thread might offer a related explanation...
http://forums.chaosgroup.com/showthr...tain-materials

Benjamin

[Vizioen]

It seems I have found the culprit. Apparently 3ds Max does something weird (who'd have guessed) when chamfering. It may seem that everything is planar but it might not be?
I selected the vertices of the cap and snap-moved them to the last vertex of the chamfer, it doesn't look like it moves and in fact it doesn't if I look to the coordinates. But something must have happened in doing that (I retried it 3 times). Because now it is solved. Any explanations?? :/





EDIT: Just tried this with more segments, it was a little harder to get rid of (make planar > move-snap to chamfer and it didn't work) I had to move-snap each ring and the center point separately for it to work and this time I even noticed they moved by 0,000000000000076 or something. So apparently the chamfer fcks up geometry.

[zoranm]

There used to be an old trick for this from " the old days" (since max has this problem from version 1.0)Just add a MeshSmooth modifier in NURMS mode and set iterations =0. It won't affect your geometry but will fix some problems with smoothing groups.It doesn't work always and it works mostly for simpler shapes but it saved me many times in "emergency" situations.Hope this helpsZoran