Removing MtoA from Maya scenes


If you don’t use Arnold, but someone has saved your scene files with MtoA loaded, then you’ll get some errors and warnings when you open that scene without MtoA.

// Error: line 0: The camera 'perspShape' has no 'ai_translator' attribute. // 
// Error: line 0: Node "perspShape" has no attribute "ai_translator". // 
// Error: line 0: The camera 'topShape' has no 'ai_translator' attribute. // 
// Error: line 0: Node "topShape" has no attribute "ai_translator". // 
// Error: line 0: The camera 'frontShape' has no 'ai_translator' attribute. // 
// Error: line 0: Node "frontShape" has no attribute "ai_translator". // 
// Error: line 0: The camera 'sideShape' has no 'ai_translator' attribute. // 
// Error: line 0: Node "sideShape" has no attribute "ai_translator". // 
// Error: line 0: The mesh 'pPlaneShape1' has no 'ai_translator' attribute. // 
// Error: line 0: Node "pPlaneShape1" has no attribute "ai_translator". // 
// Error: line 0: The mesh 'pSphereShape1' has no 'ai_translator' attribute. // 
// Error: line 0: Node "pSphereShape1" has no attribute "ai_translator". // 
// Error: line 0: The mesh 'pCubeShape1' has no 'ai_translator' attribute. // 
// Error: line 0: Node "pCubeShape1" has no attribute "ai_translator". // 
// Warning: line 0: Unrecognized node type for node 'defaultArnoldRenderOptions'; preserving node information during this session. // 
// Warning: line 0: Unrecognized node type for node 'defaultArnoldFilter'; preserving node information during this session. // 
// Warning: line 0: Unrecognized node type for node 'defaultArnoldDriver'; preserving node information during this session. // 
// Warning: line 0: Unrecognized node type for node 'defaultArnoldDisplayDriver'; preserving node information during this session. //

Here’s how to remove all the MtoA (aka Arnold) attributes and nodes.

First, don’t load MtoA. Uninstall MtoA.

Now, just loading and saving your scene will get rid of the ai_translator attributes. All that’s left to do is get rid of the unknown nodes. There’s just four (assuming nobody created any Arnold shaders or lights or standins in the scene): the four defaultArnold nodes:

ls -typ "unknown";
// Result: defaultArnoldDisplayDriver defaultArnoldDriver defaultArnoldFilter defaultArnoldRenderOptions //

Here’s a MEL script to remove all unknown MtoA nodes from a scene:

string $mtoaNodes[] = `ls -typ "unknown"`;

for ($node in $mtoaNodes){
	if (`objExists $node` && `unknownNode -q -p $node` == "mtoa"){
		print("Deleting mtoa node " + $node + "\n");
		delete $node;
	}
}

[MtoA] Warning: Renderer “arnold” does not provide batch rendered options


Not all renderers have batch render options, so if you click the box beside the Batch Render menu command:

menu_options_box

then you’ll get a warning:

// Warning: file: C:/Program Files/Autodesk/Maya2017/scripts/others/batchRenderOptions.mel line 19: Renderer "arnold" does not provide batch rendered options. // 
// Warning: file: C:/Program Files/Autodesk/Maya2017/scripts/others/batchRenderOptions.mel line 19: Renderer "mayaHardware" does not provide batch rendered options. // 
// Warning: file: C:/Program Files/Autodesk/Maya2017/scripts/others/batchRenderOptions.mel line 19: Renderer "mayaHardware2" does not provide batch rendered options. // 
// Warning: file: C:/Program Files/Autodesk/Maya2017/scripts/others/batchRenderOptions.mel line 19: Renderer "mayaVector" does not provide batch rendered options. //

All the rendering options for Arnold are in the Arnold Render Settings.

To start a batch render, click the Batch Render text in the Render menu:
render_menu

[MtoA] Creating color masks with a custom AOV and the Utility shader


In this video, I show how to a color mask AOV using a custom AOV and the Utility shader. Topics covered include:
– Creating a custom AOV
– Setting the default shader for a custom AOV
– Setting up the Utility shader to output a color for each shape
– Understanding the difference between the Color and Color ID color modes