Arnold Display Channels not Rendering Properly

[Anonymous]

My copy of mtoA that is bundled with 2019 stopped rendering on a scene that has been rendering well in the past. I am now only able to render the display alpha in IPR and in Renderview as well. All channels (RGB) do not render. I am still getting an error when I render with mtoA "Warning: [mtoa] Output driver 1 for AOV "RGBA" is null #". 

I have both tried increasing Ai lights intensity and exposure as well as reinstall my copy of maya. This happens on all scenes including just using a simple sphere mesh. The only fix that I've read on the forums for this is to make sure that Render Selected Objects Only is turned off , which it is. Any help for resolving this Arnold issue would be appreciated.

[Stephen.Blair]

Please post a detailed Arnold log, ideally for Render > Render Current Frame.

[Anonymous]

Hello Stephen,

Thanks for your quick reply. Ive attached two images of rendering with display alpha channel and all channels. Alpha channel updates in IPR so the shape node is fine. All channels renders black and gives the following errors: 

closeNodeEditorEd hyperShadePrimaryNodeEditor;
# Warning: [mtoa] Output driver 1 for AOV "RGBA" is null #
# Warning: [mtoa] Output driver 1 for AOV "RGBA" is null #
select -cl ;

The scene is only using a simple sphere and one ai area light. I've reinstalled maya 2019 a number of times to see if there was an issue with the install and it seems okay. I look forward to hearing your thoughts for resolving the mtoa rendering. 

Cheers,

Daveed

[Stephen.Blair]

https://answers.arnoldrenderer.com/questions/5832/arnold-render-error.html ?

[Anonymous]

That autodesk link explains the warning but it doesn't explain why both IPR and Arnold render view are rendering all black when all channels are selected. 

The ai area  light is at a high exposure and intensity is set to high at 4.0 for this test. The sphere has a ai standard surface shader assigned. 

All file scenes I have created when launched that used to render well in Arnold are now rendering black like this sphere test scene. 

[Stephen.Blair]

So, any scene? Can you post an Arnold log?

[Stephen.Blair]

You get the same error with the Arnold Render View? Then that warning explains why it's all 0,0,0

Let's see one of the scenes?

[Anonymous]

@Stephen.Blair 

Yes. I get the same issue with a sphere not rendering in Arnold renderView and IPR. Attached is a debug render.log file for a render of the sphere with an ai area light.  I've reset my \maya\2019\prefs as well but that didn't fix the issue either.  

[Anonymous]

@Stephen.Blair  'Attached is the simple sphere ascii scene for you to review.

[mspeer · Accepted solution]

Hi!

There is not "enough" light in the scene, caused by the scale of your scene setup.

Select your light and uncheck "Normalize" in Attribute Editor, or scale everything down by a factor of about 500.

[Anonymous]

Unchecking "Normalize" seemed to do the trick:) I'm not sure how this was checked on a previous scene / perhaps from default prefs with the new install.. Thanks @mspeer !:)