Can mirrored normal maps bug be corrected from Modo Plugin?

Forums: Can mirrored normal maps bug be corrected from Modo Plugin?
Foundry Modo (Developed by stenson, Integrated Plugin developed by Paul Kinnane)

Moderator: face_off

Can mirrored normal maps bug be corrected from Modo Plugin?

Postby adamnerva » Fri Jan 29, 2016 8:07 pm

adamnerva Fri Jan 29, 2016 8:07 pm
Hi Paul,

This is a bit of a longshot, but I have been getting annoyed by a normal map related bug in Octane, and I was wondering if it could be corrected from within the Modo plugin. Normal maps assigned to mirrored UVs render inverted. I am working on a scene that started as a real-time environment, and so utilizes lots of mirroring and such. Is there any way for the Modo Octane plugin to detect and correct/compensate for this error? Or is this a non-trivial issue that would be better to push for a fix in the Octane render engine?

Thanks.
adamnerva
Licensed Customer
Licensed Customer
 
Posts: 81
Joined: Mon Apr 27, 2015 9:01 pm

Re: Can mirrored normal maps bug be corrected from Modo Plugin?

Postby face_off » Mon Feb 01, 2016 5:01 am

face_off Mon Feb 01, 2016 5:01 am
Could you pls send me a very simple Modo scene when demonstrates this problem pls, and I will take a look.

Paul
Win7/Win10/Mavericks/Mint 17 - GTX550Ti/GT640M
Octane Plugin Support : Poser, ArchiCAD, Revit, Inventor, AutoCAD, Rhino, Modo, Nuke, DAZ Studio
Pls read before submitting a support question
User avatar
face_off
Octane Plugin Developer
Octane Plugin Developer
 
Posts: 12624
Joined: Fri May 25, 2012 10:52 am
Location: Adelaide, Australia

Re: Can mirrored normal maps bug be corrected from Modo Plugin?

Postby adamnerva » Tue Feb 02, 2016 3:53 am

adamnerva Tue Feb 02, 2016 3:53 am
OK, I sent you a PM with an LXO.

Thanks, Paul.

Normal_bug_Capture.PNG
Octane render normal map mirrored UVs bug
adamnerva
Licensed Customer
Licensed Customer
 
Posts: 81
Joined: Mon Apr 27, 2015 9:01 pm

Re: Can mirrored normal maps bug be corrected from Modo Plugin?

Postby face_off » Tue Feb 02, 2016 1:09 pm

face_off Tue Feb 02, 2016 1:09 pm
Thanks for sending the scene through. I can now reproduce the problem. I will need to submit it to Otoy for further analysis. I will post here once I know more.

Paul
Win7/Win10/Mavericks/Mint 17 - GTX550Ti/GT640M
Octane Plugin Support : Poser, ArchiCAD, Revit, Inventor, AutoCAD, Rhino, Modo, Nuke, DAZ Studio
Pls read before submitting a support question
User avatar
face_off
Octane Plugin Developer
Octane Plugin Developer
 
Posts: 12624
Joined: Fri May 25, 2012 10:52 am
Location: Adelaide, Australia

Re: Can mirrored normal maps bug be corrected from Modo Plugin?

Postby adamnerva » Tue Feb 02, 2016 6:40 pm

adamnerva Tue Feb 02, 2016 6:40 pm
Awesome! Thanks, Paul. I also sent you a Modo internal renderer shot with colorspace set to none in the image properties so you can see how it should look.

Modo-Render-Capture.PNG
Mirrored normal map rendered correctly in Modo internal render engine.
adamnerva
Licensed Customer
Licensed Customer
 
Posts: 81
Joined: Mon Apr 27, 2015 9:01 pm

Re: Can mirrored normal maps bug be corrected from Modo Plugin?

Postby face_off » Sun Feb 07, 2016 4:05 am

face_off Sun Feb 07, 2016 4:05 am
Status Update:

I can reproduce this problem. And if the normal map is plugged into the diffuse pin it renders correctly - so the UV's are fine. I have sent the scene to Otoy who have had a look. I will ask them to provide an explanation of the issue, since it's over my head.

Paul
Win7/Win10/Mavericks/Mint 17 - GTX550Ti/GT640M
Octane Plugin Support : Poser, ArchiCAD, Revit, Inventor, AutoCAD, Rhino, Modo, Nuke, DAZ Studio
Pls read before submitting a support question
User avatar
face_off
Octane Plugin Developer
Octane Plugin Developer
 
Posts: 12624
Joined: Fri May 25, 2012 10:52 am
Location: Adelaide, Australia

Re: Can mirrored normal maps bug be corrected from Modo Plugin?

Postby adamnerva » Mon Feb 08, 2016 2:36 am

adamnerva Mon Feb 08, 2016 2:36 am
Thanks!
adamnerva
Licensed Customer
Licensed Customer
 
Posts: 81
Joined: Mon Apr 27, 2015 9:01 pm

Re: Can mirrored normal maps bug be corrected from Modo Plugin?

Postby roeland » Mon Feb 08, 2016 11:22 pm

roeland Mon Feb 08, 2016 11:22 pm
There is indeed a bug in Octane which causes it to use a wrong “tangent vector” when the UV map is mirrored. This vector determines the orientation of the normal map distortion (more specifically: the color (1.0, 0.5, 0.5) specifies a distortion in the direction of this vector).

We will fix that bug, but this however will not fix the problem with this render. At the moment Octane assumes that the UV mapping is not mirrored, and it will also not mirror any distortions in the normal map. So you still end up with a normal which is mirrored around the U axis in 2 of the 4 quadrants:

Let's for example use a simple normal map:
border-tiny-corner.png
Normal map example
border-tiny-corner.png (1.99 KiB) Viewed 1597 times


And render it on a square with mirrored UV coordinates in the 4 quadrants:
example render.png


Note that although you only see one seam, the normal map is wrong in the upper right and lower left quadrant. Note the orientation of the highlights on the mirrored n.

Using just the usual UV mapping on a plane and relying on our mirror border mode for textures doesn't result in edges, but it still results in wrong orientations because the normal map distortion still needs to be mirrored in the right and bottom parts of the quad (note the bottom border).
example render 2.png


We are at the moment not planning to implement this kind of mirroring in Octane. The only way right now is to convert this normal map into a bigger normal map covering all 4 quadrants (and applying the right mirroring). Is this a common use case?

--
Roeland
User avatar
roeland
OctaneRender Team
OctaneRender Team
 
Posts: 1685
Joined: Wed Mar 09, 2011 10:09 pm

Re: Can mirrored normal maps bug be corrected from Modo Plugin?

Postby adamnerva » Tue Feb 09, 2016 12:07 am

adamnerva Tue Feb 09, 2016 12:07 am
Hey, well thanks for at least looking into it. It works in Modo, Redshift, and of course game engines, so it is doable, but different engines have different priorities and schedules.

Thanks.
adamnerva
Licensed Customer
Licensed Customer
 
Posts: 81
Joined: Mon Apr 27, 2015 9:01 pm

Re: Can mirrored normal maps bug be corrected from Modo Plugin?

Postby oguzbir » Tue Feb 09, 2016 12:17 am

oguzbir Tue Feb 09, 2016 12:17 am
roeland wrote:We are at the moment not planning to implement this kind of mirroring in Octane. The only way right now is to convert this normal map into a bigger normal map covering all 4 quadrants (and applying the right mirroring). Is this a common use case?
Roeland


Roeland I've already mentioned this in 3dsmax bug report, thinking that it is a bug related to Max plugin. Not being able to apply the mirroring as it should.
Please read my post here.
viewtopic.php?f=81&t=52450
Well I think this is actually an essential and frequently common case, I guess especially for octane plugins where use of mirroring or symmetry bunch of times.
So now I seems like we lost that functionality entirely. It's sad.
The same scenario doesnt work with Displacement though. Just when you use it as bump or normal bump. ( havent tried it with specularity maps.)
So there is no way to solve this?
My Portfolio
windows 10 Pro. |1070 + 1070 + 1070 + 1070 | i7 @4.5Ghz
User avatar
oguzbir
Licensed Customer
Licensed Customer
 
Posts: 715
Joined: Fri Jun 25, 2010 12:30 am
Next

Return to Foundry Modo


Who is online

Users browsing this forum: No registered users and 3 guests

Tue Sep 25, 2018 10:34 pm [ UTC ]