Author Topic: Arnold 5 Rendering looks nothing like IRAY in Painter  (Read 8380 times)

I'm having a very hard time duplicating the exact results from Substance Painter into Maya and rendering with Arnold 5.

I'm working with PBR Metallic Roughness workflow, so I exported my textures exactly as indicated at: https://support.allegorithmic.com/documentation/display/integrations/Arnold+5+for+Maya (ONLY AS PER THE Substance Painter side, I'm not using the plugin). I've also exported with the document settings as Arnold 5 supports this work flow. Just to be sure I also rendered it with the Arnold config, no difference.

I made a test model and rendered it with IRAY in Substance Painter:



Then I made a render using Arnold (Not the best model because I don't have a lot of effects, but you wont see any bumping or texture on the skin):



I couldn't use a model I'm working on due to certain reasons, but it's much more organic with texturing and scales. The model when rendered in Arnold is very glossy, and doesn't show the textured effects like the little scratches and scales anything near what you see in Substance Painter.

Maybe it's a lighting issue.... But I've tried with many models, and setups, and all failed.

My current settings are as follows in Maya:







My IOR isn't grayed out like in the guide above, but I left it at 1.520. I have my Roughness / Metallic / Normal set as RAW not sure why it shows Color Space -> Color Management Off even when its connected, but goes back to RAW if you release it. My color management is setup as below:



I'm finding the result worsen if the textures contain a lot of detail, as you would find in organic textures.

What I'm I doing wrong that the results are so different? Or is this normal and how things are supposed to port over?

Here is a sample of a more organic part of a model.

Rendered in Substance Painter:


Rendered in Arnold with Sky Dome no HDR:


Rendered in Arnold with Sky Dome and HDR:


The amount of variance makes it extremely hard for produce production work. Hopefully someone can direct me to improving the renders.
Last Edit: March 08, 2018, 02:29:27 am

Sorry, I am neither a Maya nor an Arnold user, but does this thread help ? : https://forum.allegorithmic.com/index.php/topic,22422.0.html
The issue looks the same to me (roughness not transferring properly)
Last Edit: March 08, 2018, 12:06:29 pm

Thank you. I took at look at that thread and all my maps are fine, and I even took them into Photoshop and exported to be sure, same result sadly.

Could it be possible that it's a lighting issue? I honestly cannot see what I'm doing wrong here.

I did another lighting setup and was able to do this:

Painter:


Old Render in Arnold:


New Renders in Arnold with lighting change:



New Renders in Arnold using same HDRI as in Painter (Not great - guessing because Painter somehow lights way better):
Last Edit: March 09, 2018, 07:15:29 am

About Color Management:
The Color Management option is grayed out on your File node because of a Maya 2016/2017 bug. Don't duplicate the File nodes with CTRL+D in the Hypershade. Instead use the Edit -> Duplicate -> With Connections to Network command, or create new File nodes.
Tip: Drag and drop the files into the Hypershade.

About shading/texturing:

If you set everything correctly (Substance Painter export, Shader settings, File nodes – Color Management, Render settings, Lights) the results should be almost identical.
In your case you may have missed something. Create a totally new Substance project, don't change anything, create material, export your textures in Tiff format with the Arnold 5 (AIStandard) preset. Drag and drop the files into Hypershade, set the Color Management settings correctly (everything is RAW, accept the Base Color – that is sRGB). Turn on Alpha is Luminance for Metalness, Roughness and Height (if you using it).

Tip for IBL:
In Arnold you have to rotate the aiSkyDomeLight (Rotate Y = 270).

Tip for exporting textures from Substance Painter:
Use the default Arnold 5 (AIStandard) export preset. Use Tiff format.

By the way the Arnold 5 Substance Painter Guide is correct.

Here are some examples:















Last Edit: March 08, 2018, 10:54:49 pm
I'm an Environment Artist and R&D Generalist at Digic Pictures

Thank you. I'll give this another go and post back with my result.

I'm using the Metallic Roughness workflow, how does one attach a height map to aiStandardSurface? I don't see a plug for it.

You can use Height maps as Displacement or Bump.
I'm an Environment Artist and R&D Generalist at Digic Pictures

I just finished a render. I noticed I can avoid the color management problem by directly loading the textures in the shader attributes screen, and they're no longer grayed out. Dragging and dropping the textures wouldn't work sadly. :(

This was a render from Substance Painter:


This was a render from Arnold TIFF 16:


This was a render from Arnold EXR 32F:


I also tried the same with just artificial leather.

From Substance Painter:


From Arnold with TIFF 16:


From Arnold with EXR 32F:


I don't think it's a lighting issue because if you look closely at both samples, you'll notice loss in depth on the detail. The first one doesn't chisel properly at the center, and the second (leather) has almost no creases in the leather itself from Arnold.

It really appears like something is missing detail wise, I just cannot pin point the problem.

Even in your sample:


I can see loss in detail, but it's not as bad as what I'm experiencing. Maybe it's just my eyes?  :o

I also tried using my height map, but it doesn't make a difference in this render.

--
EDIT: I noticed that in Substance Painter, under Shader and Common Properties you have Height Force, I can lower this and it will match my Arnold output, so this tells me I'm missing height details.
Last Edit: March 09, 2018, 07:13:44 am

Based on my prior test playing around with the height setting in Substance Painter -> Shader - Common Properties -> Height Force, this told me my height information isn't going through properly because I was able to lower it below the default (1) and get a similar look that Arnold rendered at. (This means loss in height details).

I couldn't successfully attach my height map in Maya under my current workflow, as it didn't make a difference. So I just exported my mesh normal with all information, put it back into my project, rebaked it, then exported the files back to Maya. I can see a better result, not 100% the same, but better!

Substance Painter - IRAY:


Old Arnold Render:


New Arnold Render - Normal + Height Combined:


New Arnold Render - Normal + Height Combined - High Res Textures:


I think this is a good sign so far. I'll look more into baking my normals with all the details stored in height channels.
Last Edit: March 09, 2018, 07:11:57 am

I think you overcomplicate this a bit. In Arnold usually the normals looks a bit smoother, other than that it's just an intensity problem.
Use the aiNormalMap not the bump2d node. In that case you'll have control over the normal strength.

You don't have to use 16 bit/channel images to get correct results.

Height output is not equivalent with the calculated (Base Normal +Height + Normal) normal map results, because of how the materials are created (sbsar files).

Drag and Drop the texture files into the Hypershade editor (work area) always works. It's the simplest way to add textures to a since ever.

I don't understand this:
“I noticed I can avoid the color management problem by directly loading the textures in the shader attributes screen”
What's the shader attributes screen? You mean Shader Editor?

Also what's this:
“Normal + Height Combined:”

Cheers, D

P.S.
If you want, I can send you a Maya file and the textures of course.
I'm an Environment Artist and R&D Generalist at Digic Pictures

I think you overcomplicate this a bit. In Arnold usually the normals looks a bit smoother, other than that it's just an intensity problem.
Use the aiNormalMap not the bump2d node. In that case you'll have control over the normal strength.

You don't have to use 16 bit/channel images to get correct results.

Height output is not equivalent with the calculated (Base Normal +Height + Normal) normal map results, because of how the materials are created (sbsar files).

Drag and Drop the texture files into the Hypershade editor (work area) always works. It's the simplest way to add textures to a since ever.

I don't understand this:
“I noticed I can avoid the color management problem by directly loading the textures in the shader attributes screen”
What's the shader attributes screen? You mean Shader Editor?

Also what's this:
“Normal + Height Combined:”

Cheers, D

P.S.
If you want, I can send you a Maya file and the textures of course.

Thanks for all the assistance, I really appreciate it! I'm still pretty green to Arnold, and I'm just now moving into a PBR Metallic Roughness workflow.

I had no idea I was able to use anything but bump2d node, so I hooked up aiNormalMap and the results are pretty good!

Using bump2d:


Setting up aiNormalMap:


Using aiNormalMap - Upped the Strength:


"Drag and Drop the texture files into the Hypershade editor (work area) always works. It's the simplest way to add textures to a since ever."

The problem with drag and drop or even making nodes manually is this will happen:




It will still apply correctly even though in the gray, but if you remove the connection with the node from the shader it will allow you to select the color profile again, and locks once plugged. It only does this for raw profiles, not sRGB.

If I load the textures through this:


It will create the attachments, and not gray out the profiles.



"Also what's this:
“Normal + Height Combined:”"

All it means is that I took all the height detail and baked as per this video: https://www.youtube.com/watch?v=0M6PDzxJtWY&index=26&list=PLB0wXHrWAmCx994Cb7iRFSmupYHFw5DTx

By doing what you said and using aiNormalMap, not bump2d, I can achieve the same result without re-baking height information.

The problem is I was plugging in my normals into bump2d directly and the intensity was too low, but when I baked all that detail and reloaded the map, it worked with bump2d alone, but aiNormalMap works without doing any of this by upping the Strength value. I had no idea as I'm pretty green to Arnold.

I believe my connections are correct?


It looks like you've solved my problem!  ;D Thank you very much.

Edit: I fixed the color profile problem, was a Maya bug, just updated my program and it's fine now! :)
Last Edit: March 09, 2018, 02:43:20 pm

Great!
Oh, the Maya update. Next time I should ask that first. :)
Cheers, D
I'm an Environment Artist and R&D Generalist at Digic Pictures