Hello Wilkolak,

Do you think you can send us that scene + textures so we can try that on our side ?

Thank you,

-- aghiles

Hello Wilkolak,

We get exact the same render with Mental Ray. I guess there must be something strange with the export :(

Have a look at this comparison, top image is MR, bottom image is 3Delight.



-- aghiles

To be honest I've tried most of combination in Mudbox exporter already. Most of them was giving even worse results like visible UV seams and so on. The thing which is strange for me is that when I use this map to 'Sculpt using map' in Mudbox none of this artifacts show up.

Anyway. What's the best method to create maps for 3delight? xNormal, Softimage ultimapper, ZBrush? Is there any known-to-be-working or even better 'officially supported/approved' workflow for Mudbox or any other soft?

wilkolak wrote:

To be honest I've tried most of combination in Mudbox exporter already. Most of them was giving even worse results like visible UV seams and so on. The thing which is strange for me is that when I use this map to 'Sculpt using map' in Mudbox none of this artifacts show up.

Anyway. What's the best method to create maps for 3delight? xNormal, Softimage ultimapper, ZBrush? Is there any known-to-be-working or even better 'officially supported/approved' workflow for Mudbox or any other soft?

Looking back at the file I was using for the test, I see that what I had actually done was set the Geometry Approximation to Fine in Softimage and also adjusting the length and sharpness makes a difference. Prior to setting it to fine there were artifacts. (in Mental Ray)

The other thing is the Scale Change Range node which can have a drastic effect on the result. I don't think the smoothing setting did anything in this particular case.

But that said, I can report that I tested my same scene in Mental Ray with Final Gather (a not so nice looking brute force method if set to Exact) and it was showing artifacts still. 3Delight renders the scene about 4x faster even on 2 cores. Unfortunately it deals with the displacement settings completely differently and if GI set to Point Based it shows up artifacts, worse than Mental Ray. And further more the displacement map is completely off.

However the same scene rendered in Vray, looks exactly like the original sculpt, has no artifacts at all and looks far better than 3Delight or Mental ray.

So my conclusion can only be I don't fully understand how to work displacements in Mental Ray or 3Delight well enough to find the source of the artifacts. But that it can be also concluded that the source of the artifacts between Mental Ray and 3Delight are likely the same. So that if you solved it in Mental Ray view it might well render properly in 3Delight - just a guess. But clearly 3Delight treats these displacements completely differently. In my case, horribly.

So I'd be interested in the magic settings as well.

Why is it that rendering from Mudbox in Vray looks perfect? The same displacement settings in Mental Ray look basically the same but with artifacts. The 3Delight render is completely off from the original along with more artifacts and none of the settings seem to make a great difference.

Clearly different render solutions treat things differently. That can be expected. But I just don't get why 3Delight has particular difficulty with the same geometry settings in Softimage compared to Mental ray and Vray.

Is this just a Mudbox thing? Or is this the case with other displacement maps as well?

The places I can get a change are in the Geometry Approximation and the Scalar Change Range node. That along with the subdivision max in 3Delight. But nothing seems to get the good result so far.

I'd have to do more experiments to nail it down. But if anyone has any useable tips it would be handy.

Last edited by CineArtist (2012-04-22 00:30:15)

I've played a lot with Geometry Approximation page but I believe 3delight overrides most of the settings there according to the docs.
3rd sub-d level is low I agree but I used it just for this simple test scene. My 'real' model which I tried is lvl 5 ~10.000.000 polys. I've just tried to reproduce the issue with as little steps as I could before I write for support. ;)

Will try on Monday exporting model/maps from ZBrush. Will see if this will help anything.

CineArtist wrote:

It does not indicate that you worked with any settings in the Geometry Approximation page. And second that 3 levels in Mudbox is not very high to get smooth results I don't think from my experience.

There is only one setting from GeoApprox PPG, used by 3delight: Max Displace value, and this one is for faster rendering. Should be just a bit more than maximal displacement, you have in Render Tree.
Everything else is performed automatically. 3Delight, as any other RenderMan compliant renderer, does all tessellation all the time.
Next important setting is shading rate, if you want sharper displacement, you have to set a lower shading rate value.
And next one could be Smooth Subdivision Threshold - if you set this to zero (in global render options, or by 3Delight property), that's a always smooth subdivision, also typical for Renderman compliant renderer.

Hello,

I am not a Mudbox expert but is there an "overpaint" parameter you can adjust. 3Delight generally uses wider filters for its texture lookups and this could make the texture appear "fragmented" between the different UV islands.
If there is such a parameter, it should be increased.

We are checking on our side if there is something we can do.

-- aghiles

wilkolak wrote:

Sure!

It's project from Softimage 2012.5, using 3delight for Softimage 3.1.0 I believe. The free one.
http://dl.dropbox.com/u/4536220/displacement_test.7z

Hello guys,

I am not mudbox expert, but is it alright that this displacement texture projected to a plane has the same artifacts?