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Arnold shaders not showing up in Assign New Material window
If you’re running Maya 2013 and you don’t see the Arnold shaders in the Assign New Materials window, then you need to install the latest Maya 2013 service pack. After that, you’ll be able to...
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Exporting user data parameters to Arnold from Maya
You can add attributes to shape nodes in Maya, and MTOA will export those extra attributes as user data in Arnold shape nodes. For example, you use this mechanism to add user data to a procedural node....
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[MtoA] Editing Arnold attributes on multiple objects
If you need to change the same Arnold attributes on many nodes, use the Attribute Spreadsheet. For example, suppose you wanted to turn off the Opaque attribute on a number of objects in your scene....
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Another case of a missing entry point
In this case, a user installed the latest MtoA, but when he went to load mtoa.mll in the Plug-in Manager, he got this error: --------------------------- Settings/Preferences: maya.exe - Entry Point...
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[Maya] Socket error creating command port
NOTE: This is a Maya issue that can happen with any renderer, including mental ray. Like many other Maya users, I started getting this error when I tried to batch render: // Error: line 1: Socket error...
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[Maya] The case of Xgen and [Error 6] The handle is invalid
This post is about a Maya issue on Window. It’s not an MtoA or Arnold issue. Whenever I tried to export the selection as an XGen archive, I’d get [Error 6] The handle is invalid. [Error 6] The handle...
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The case of the missing PyMel debug log file
In several recent cases, I had to figure out why MtoA wouldn’t load on a render farm. The root cause turned out to be the PyMel debug log: ~/pymel.log If PyMel cannot find or open ~/pymel.log, that...
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The case of the “cannot remove alias” RuntimeError
In this case, mayabatch reported some runtime errors when loading a certain scene: # Traceback (most recent call last): # File "C:\solidangle\mtoadeploy\2015\scripts\mtoa\callbacks.py", line 415, in...
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The case of the disappearing particles
In this case, nParticles (render type = point) weren’t visible behind a refractive plane: For the points render type, you get an Arnold points shape (with mode “disk”), so I exported an ASS file to see...
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[MtoA] Normal mapping with mayaBump2d
mayaBump2D has an RGB parameter for normal maps, and it’s named “normal_map”: C:\solidangle\mtoadeploy\2015\bin>kick -l ..\shaders -info mayaBump2D node: mayaBump2D type: shader output: RGBA...
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[MtoA] Flushing the texture cache from Python
MtoA provides an arnoldFlushCache command (and the Arnold > Flush Caches menu uses that command). You can call it from Python like this: import maya.cmds as cmds cmds.arnoldFlushCache(...
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[MtoA] mtoa missing from Plug-in Manager
If mtoa.mll is not listed in the Plug-in Manager, that means that Maya did not find the MtoA module file (mtoa.mod). And if you try to manually load mtoa.mll, you’ll get errors like this: // Error:...
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[MtoA] Switching between multiple versions of MtoA
If, like me, you need to switch between different versions of MtoA, here’s a recipe for setting that up. First, you have to install multiple versions. As you probably already know, the MtoA installer...
View ArticleSetting up Arnold render nodes
I’ve seen several variations of this question recently. Usually there’s some confusion about “Arnold standalone” and what’s actually required on a render node. If you rendering scene files from Maya,...
View ArticleRemoving 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...
View Article[mtoa] Using dirmap to update paths
How can you update the paths used to load textures, standins, or volumes? Use dirmap. You can use dirmap to update the paths for the following nodes: aiImage (Image Name) aiStandin (Path) aiVolume...
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