WARNING : [ass] node name already in use


Shader nodes must have unique names.

So if you’re using standins, each standin ASS file has to have unique shader node names. Otherwise you’ll get unexpected results when you render, like all standins having the same shading, or some “flickering” in animation if the order of standin loading changes.

In the Arnold log, look for “node name already in use” warnings:

WARNING | [ass] standin_01.ass line 50: node name "aiStandard1SG" already in use
WARNING | [ass] standin_01.ass line 58: node name "aiStandard1" already in use
WARNING | [ass] standin_01.ass line 118: node name "file1" already in use
WARNING | [ass] standin_01.ass line 147: node name "aiNoise1" already in use

 

If each standin should look different, you need to have unique shader names in each ASS file. If you’re using MtoA, that includes the name of the SG node (for example, aiStandard1SG).

WARNING mtoa_shading_groups: unresolved reference


Any time you see “node … is not installed” and “unresolved reference” warnings when you try to kick an ASS file exported from Maya, the problem is missing MtoA shaders.


00:00:00 18MB WARNING | [ass] line 259: node "MayaFile" is not installed
00:00:00 18MB WARNING | [ass] line 288: node "MayaShadingEngine" is not installed

00:00:03 23MB WARNING | [ass] line 238: pSphereShape1.mtoa_shading_groups: unresolved reference to 'aiStandard2SG'
00:00:03 23MB WARNING | [ass] line 137: aiSkyDomeLightShape1.color: unresolved reference to 'file1'
00:00:03 23MB WARNING | [ass] line 188: pPlaneShape1.shader: unresolved reference to 'aiStandard1SG'
00:00:03 23MB WARNING | [ass] line 197: pPlaneShape1.mtoa_shading_groups: unresolved reference to 'aiStandard1SG'
00:00:03 23MB WARNING | [ass] line 229: pSphereShape1.shader: unresolved reference to 'aiStandard2SG'

When you render with kick, you need to specify the location of the MtoA shaders. You can do this several ways:

  • Set the ARNOLD_PLUGIN_PATH environment variable. For example:
    export ARNOLD_PLUGIN_PATH=/home/render/solidangle/mtoa/2016/shaders
    set ARNOLD_PLUGIN_PATH=C:\solidangle\mtoadeploy\2016\shaders
  • Use the kick -l flag to specify the MtoA shader location.
  • In Maya, set the Shader Search Path in the Arnold Render Settings, then export the ASS file.

[RLM] Communications error with license server (­17)


These warnings mean that Arnold can connect to the RLM license server, but Arnold cannot connect to the solidangle ISV server:

00:00:12 14MB WARNING | [rlm] * Communications error with license server (­17)
00:00:12 14MB WARNING | [rlm] * Connection refused at server (­111)

Usually the problem is that the solidangle ISV server is not running.

You can check the status of the solidangle ISV server with RLM Web Admin. I like the get the RLM diagnostics (Diagnostics > Run Diagnostics) from RLM Web Admin and review that.

In rare cases, the problem is something else, such as:

  • Some sort of network connection problem. For example, I recently had a case where we would get these warnings when we used the IP address of the license server in solidangle_LICENSE. But as soon as we switched to using the hostname, everything worked.
  • Another RLM instance is running and listening to port 5053, and that instance doesn’t have a solidangle ISV running. I heard about this second-hand, from a customer; I didn’t see it with my own eyes and I don’t know how it’s possible. You can have multiple RLM instances running, but each instance has to have a different port otherwise you get ” “Port 5053 in use, waiting…” messages and the second RLM won’t start.

ERROR | [mtoa] [xgenTranslator] Could not find xgen_procedural in search path $ARNOLD_PLUGIN_PATH


This error

ERROR   | [mtoa] [xgenTranslator] Could not find xgen_procedural in search path $ARNOLD_PLUGIN_PATH

happens only when MtoA is first loaded, and it can be safely ignored. It doesn’t cause any problems when you render, and MtoA loads the XGen procedural from the MtoA procedurals folder.

The error is a consequence of how MtoA searches folders when it loads extensions. If you really need to get rid of the error, you can try copying the xgen_procedural library to the MtoA shaders folder.

[C4DtoA] Render failed! Please check the log for more details.


c4dtoa_render_failed

The Arnold log is important, not just for troubleshooting and getting help from us at Solid Angle, but also for understanding what’s going on when Arnold renders your scene.

But, first things first: where’s the log? The Arnold log is output to the Cinema 4D Console:
c4dtoa_console

To open the Console, click Script > Console.
c4dtoa_script_console

You can set the verbosity level in the Render Settings > Diagnostics. By default, the verbosity level is Warnings, but by increasing it to Info, you’ll get the % done log entries. You can also send the log to a file (good for logging support cases!).
c4dtoa_diagnostics

[RLM] No ISV servers to start redux


The technical reason for a “No ISV servers to start” message is that that RLM could not read the ISV line from the license file.

So, for example, if you somehow save the license file as a binary file that looks like this:

books8mk

then you’ll get No ISV servers to start, because obviously there’s no ISV line in that file.

Note: You’ll also see The hostname in the license file(s) may be incorrect, but that warning can always be safely ignored.

05/14 09:17 (rlm) 
05/14 09:17 (rlm) WARNING: No license file for this host (StephenBlair-PC)
05/14 09:17 (rlm)          The hostname in the license file(s)
05/14 09:17 (rlm)          may be incorrect
05/14 09:17 (rlm) 
05/14 09:17 (rlm) License files:
05/14 09:17 (rlm)     arnold_eval_90b11c647d93_20150514.lic
05/14 09:17 (rlm) 
05/14 09:17 (rlm) RLM License Server Version 11.2BL2

	Copyright (C) 2006-2014, Reprise Software, Inc. All rights reserved.

05/14 09:17 (rlm) License server started on StephenBlair-PC
05/14 09:17 (rlm) Server architecture: x64_w2
05/14 09:17 (rlm) License files:
05/14 09:17 (rlm)     arnold_eval_coffee0000_20150514.lic
05/14 09:17 (rlm) 
05/14 09:17 (rlm) Web server starting on port 5054
05/14 09:17 (rlm) Using TCP/IP port 5053
05/14 09:17 (rlm) ... adding UDP/IP port 5053
05/14 09:17 (rlm) (No ISV servers to start)

[MtoA] Finding your Arnold log file


When you enable file logging, it can seem a bit of a mystery where the .log files end up. You may find log files in different folders of your project, like the scenes folder, or the sourceimages folder.
mtoa_file_logging
Here’s how it works.

  • If the MTOA_LOG_PATH environment variable is set, the log files are saved to the folder specified by MTOA_LOG_PATH.
  • If MTOA_LOG_PATH is not set, the log files are saved in the current workspace directory (in MEL, that’s workspace -q -directory). In other words, the log files are saved to last place you went with the Maya file browser. If you haven’t used the file browser yet, the log file is saved in the root folder of the project.
  • If you click the folder icon beside the Filename text box, you can choose where the log files are saved.

Note that the log files will always include the frame number, so you’ll get arnold.1.log, arnold.2.log, and so on.

[MacOSX] Troubleshooting with dtruss


In a previous post, I looked at how things could go wrong in the file ~/pymel.log wasn’t accessible. On Windows, this was fairly easy to track down using Process Monitor:
pymel.log

On Mac OS X, I had to use dtruss. For example, I ran this command to trace the syscalls of the Maya Render command:

sudo dtruss -f -t open_nocancel -n Render 2> /var/tmp/mtoarender.log

When the render job failed, I checked the log file, and found this line:

11668/0x35deb: open_nocancel("/Users/stephenblair/pymel.log\0", 0x601, 0x1B6) = -1 Err#13

One important gotcha: if you repeat the render, you won’t find any mention of pymel error in the dtruss output. My guess is that at that point, the Render command ends up going through the file system cache, so dtruss doesn’t see the attempt to find pymel.log.

Here’s a quick summary of the dtruss command I showed above:

  • Use sudo to run dtruss, because it needs additional privileges.
  • -f tells dtruss to follow any child processes (like mayabatch) launched by Render
  • -t filters the trace for open_nocancel system calls
  • -n tells dtruss to trace the process named “Render”
  • 2> /var/tmp/mtoarender.log redirects the dtruss output to a file

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 deferredCallback
#     func(*args, **kwargs)
#   File "C:\solidangle\mtoadeploy\2015\scripts\mtoa\aovs.py", line 471, in createAliases
#     pm.aliasAttr(sg + '.ai_aov_' + name, remove=True)
#   File "C:\Program Files\Autodesk\maya2015\Python\lib\site-packages\pymel\internal\pmcmds.py", line 134, in wrappedCmd
#     res = new_cmd(*new_args, **new_kwargs)
# # RuntimeError: 'aiStandardSG.ai_aov_direct_specular' is not a unique name.  Cannot remove alias.

Now, even though I have the advantage of access to the MtoA source code, the problem remained: how do I fix the scene and stop these errors? To find a solution (and understand the problem) I had to resort to examining the Maya ASCII version of the scene.

The “fix” was to clear the AOV names on the shadingEngine node:

setAttr "aiStandardSG.aovs[0].aov_name" -type "string" ""; 
setAttr "aiStandardSG.aovs[1].aov_name" -type "string" ""; 
setAttr "aiStandardSG.aovs[2].aov_name" -type "string" ""; 

The problem is that the shadingEngine node has some named custom AOVs, but no corresponding “attribute alias” list. So the AOV name couldn’t be found in the alias list, which in the error message came out as “not a unique name”.

In the Maya ASCII version of the problem scene, I saw this:

createNode shadingEngine -n "aiStandardSG"; 
	addAttr -ci true -h true -sn "aal" -ln "attributeAliasList" -dt "attributeAlias"; 
	setAttr -s 4 ".aovs"; 
	setAttr ".aovs[0].aov_name" -type "string" "direct_diffuse";
	setAttr ".aovs[1].aov_name" -type "string" "direct_specular";
	setAttr ".aovs[2].aov_name" -type "string" "indirect_diffuse";
	setAttr ".aovs[3].aov_name" -type "string" "indirect_specular";

instead of this:

createNode shadingEngine -n "aiStandard1SG";
	addAttr -ci true -h true -sn "aal" -ln "attributeAliasList" -dt "attributeAlias";
	setAttr ".ihi" 0;
	setAttr ".ro" yes;
	setAttr -s 4 ".aovs";
	setAttr ".aovs[0].aov_name" -type "string" "direct_diffuse";
	setAttr ".aovs[1].aov_name" -type "string" "direct_specular";
	setAttr ".aovs[2].aov_name" -type "string" "indirect_diffuse";
	setAttr ".aovs[3].aov_name" -type "string" "indirect_specular";
	setAttr ".aal" -type "attributeAlias" {"ai_aov_direct_diffuse","aiCustomAOVs[0]",
			"ai_aov_direct_specular","aiCustomAOVs[1]",
			"ai_aov_indirect_diffuse","aiCustomAOVs[2]",
			"ai_aov_indirect_specular","aiCustomAOVs[3]"} ;

I don’t know how the user managed to get the scene into that state 😉