Ingredients
Procedure
hat tip: Fred
If you have several versions of MtoA, you can switch between them by editing your Maya.env and mtoa.mtd files before you start Maya. These two files are located under your MAYA_APP_DIR folder.
For example, C:\Users\SOLIDANGLE\Documents\maya\2013-x64\Maya.env.
MAYA_RENDER_DESC_PATH = C:\solidangle\mtoadeploy\2013.0.22.0 PATH = %PATH%;C:\solidangle\mtoadeploy\2013.0.22.0\bin
And C:\Users\SOLIDANGLE\Documents\maya\2013-x64\modules\mtoa.mod:
+ mtoa any C:\solidangle\mtoadeploy\2013.0.22.0
The mtoa.mod file is put there by the MtoA installer.
The MtoA installer always wants to remove any other installed version, so if you want to keep multiple versions around, you can do one of the following:
For example, if you have MtoA 0.21 installed in
C:\solidangle\mtoadeploy\2013
copy that folder to
C:\solidangle\mtoadeploy\2013-0.21.0
Then install MtoA 0.22 (during the install, you may want to change the default install folder to something like C:\solidangle\mtoadeploy\2013-0.22.0).
After that, you’ll have both MtoA 0.22 and 0.21, and you can switch between them.
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. Here’s how to do it:
In this blog post, I’ll quickly step through an example of how to use the <attr> token in the Maya File node.
Add a "mtoa_constant_" attribute to the shape node.
Put the name of the texture file in the extra attribute:
Use the token in the Image Name. Note that I have a relative path, so I have to make sure that I’ve set a project.
Now I’ve got something that will render in Maya. If I want to export this to an ASS file and render it with kick, I need to add a Texture Search Path (and optionally, a shader search path if I don’t want to use kick -l).
Here’s the texture-related parts of the exported ASS file:
options
{
...
texture_searchpath "[MY_PROJECT_PATH]"
...
}
polymesh
{
name pPlaneShape1
...
declare myFileName constant STRING
myFileName "noicon.png"
}
standard
{
name aiStandard1
Kd_color file1
}
MayaFile
{
name file1
filename "/sourceimages/<attr:myFileName>"
}
Notice how MtoA exported a relative path instead of an absolute. This happens only if you have a token in the filename; otherwise, you always get an absolute path.
And here’s a screenshot to show all this working, both in Maya and in Arnold:
To use an environment variable in one of the Arnold search paths, you just have to put the environment variable in square brackets [ ].
For example, [ARNOLD_PLUGINS_PATH] or [MY_TEXTURE_PATH].
A search path can include many paths; just use a semi-colon (;) to separate each path. For example, here’s a search path that includes three different locations:
[ARNOLD_PLUGINS_PATH];[USERPROFILE]\Dev\shaders\bin\Release\x64;[MY_PLUGINS_PATH]
So, what’s this Preserve Layer Name setting do?
Preserve Layer Name is for single-layer EXRs, and it determines whether or not the AOV is written into the pre-defined R,G,B,A channels.
By that, I mean that if Preserve Layer Name = False, then a single-layer EXR will have these channels:
And if Preserve Layer Name = True, then the single-layer EXR will have channels like this (that include the “layer name”):
Channel names like “Arnold_Direct_Diffuse.R” can cause problems with some software, so by default Preserve Layer Names is set to False.
Note that Preseve Layer Names applies to single-layer EXRs only. If you’re writing out multi-layer EXRs, you’ll always get names like “Arnold_Direct_Diffuse.R”.
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.
Add some extra attributes to a shape node, using the naming convention mtoa_constant_parameter-name. That is, the attribute name must always start with “mtoa_constant_”.
Export to ASS. In the .ass file, your extra attributes will be declared as user parameters:
procedural
{
name ArnoldStandInShape
dso "C:/Users/SOLIDANGLE/Dev/MyProcedural.dll"
min -9.63329697 0 0.861843109
max -6.73797035 3.62841082 9.87797546
matrix
1 0 0 0
0 1 0 0
0 0 1 0
0 0 0 1
declare MyVector constant VECTOR
MyVector 0 0 0
declare MyFloat constant FLOAT
MyFloat 0
declare MyInteger constant INT
MyInteger 0
declare MyBoolean constant BOOL
MyBoolean off
declare MyString constant STRING
MyString ""
}
Here’s what you’ll get in Maya for the different verbosity levels.
In general, the higher the verbosity, the more diagnostic log information you get.
Each verbose level includes everything in the lower levels.
In brief, here’s how the verbosity levels work in MTOA 0.21:
Here’s a bit more detail on the verbosity levels in MTOA 0.21.
| 0 | Absolute silence. Nothing will be logged, no matter what happens. |
| 1 | ERRORS, WARNINGS, and, in the case of a crash or other “abnormal program termination”, the backtrace (stack contents). |
| 2 | Basic information |
| 3 | Progress messages. |
| 4 | Render statistics, and plugin loading information. |
| 5 | Everything except diagnosics. Verbosity levels 4 and 5 are pretty much the same, except that level 5 adds:
|
| 6 | Everything, including diagnostics. |
In MTOA 0.20 and earlier, the verbosity levels were different:
| 0 | Absolute silence. Nothing will be logged, no matter what happens. |
| 1 | ERRORS and, in the case of a crash or other “abnormal program termination”, the backtrace (stack contents). |
| 2 | WARNINGS |
| 3 | Basic information. |
| 4 | Progress messages, render statistics, and plugin loading information. |
| 5 | Everything except diagnosics. Verbosity levels 4 and 5 are pretty much the same, except that level 5 adds:
|
| 6 | Everything, including diagnostics. |
Here’s some samples of the different types of log output:
WARNINGS, ERRORS, and information
00:00:00 516MB | log started Thu Dec 13 10:27:49 2012 00:00:00 516MB | Arnold 4.0.10.2 windows icc110 oiio1012 rlm932 (build date: Oct 30 2012 15:25:33) 00:00:00 516MB | running on SOLIDANGLE-PC 00:00:00 516MB | 1 x Intel(R) Xeon(R) CPU E3-1240 V2 @ 3.40GHz (4 cores, 8 logical) with 16334MB 00:00:00 516MB | Windows 7 Professional Service Pack 1 (version 6.1, build 7601) 00:00:00 516MB | 00:00:05 516MB WARNING | [rlm] could not connect to license server on 5053@localhost 00:00:05 516MB | 00:00:05 516MB | there are 0 lights and 1 object: 00:00:05 516MB | 1 polymesh 00:00:05 516MB | 00:00:05 516MB | rendering image at 640 x 480, 3 AA samples, 2 GI samples, 1 GI bounces 00:00:05 516MB | active camera: 'perspShape' 00:00:05 516MB | initializing 11 nodes ... 00:00:05 516MB | node initialization done in 0:00.00 00:00:05 519MB | creating root object list ... 00:00:05 519MB | scene bounds: (-6.33536005 -4.01219463 -10.337409) -> (6.23116827 6.43629837 13.2852964) 00:00:05 519MB | updating 11 nodes ... 00:00:05 519MB | node update done in 0:00.00 00:00:05 519MB WARNING | [aov] driver "defaultArnoldDriver@driver_exr.RGB" does not support POINT2 pixels 00:00:05 519MB WARNING | [aov] driver "defaultArnoldDisplayDriver@renderview_display" does not support POINT2 pixels 00:00:05 519MB WARNING | [aov] driver "defaultArnoldDriver@driver_exr.RGB" does not support POINT2 pixels 00:00:05 519MB ERROR | [aov] no valid outputs - can't continue 00:00:05 519MB | 00:00:05 519MB | releasing resources 00:00:05 516MB
Progress messages (at 5% increments during rendering)
00:00:05 492MB | starting 8 bucket workers of size 64x64 ... 00:00:05 503MB | 0% done - 27 rays/pixel 00:00:05 504MB | 5% done - 108 rays/pixel 00:00:06 505MB | 10% done - 101 rays/pixel ... 00:00:07 500MB | 100% done - 33 rays/pixel 00:00:07 499MB | bucket workers done
Render statistics
which includes things like scene creation time, render time, memory consumed, ray counts, lighting calculations, shader calls, geometry stats, and tesselation.
00:00:07 499MB | ----------------------------------------------------------------------------------------- 00:00:07 499MB | ray counts: (/pixel , /sample) (% total) (avg. hits) (max hits) 00:00:07 499MB | camera 2946240 ( 9.00, 1.00) ( 31.80%) ( 0.24) ( 1) 00:00:07 499MB | shadow 1303706 ( 3.98, 0.44) ( 14.07%) ( 0.00) ( 0) 00:00:07 499MB | diffuse 3339596 ( 10.20, 1.13) ( 36.05%) ( 0.29) ( 1) 00:00:07 499MB | glossy 1675254 ( 5.12, 0.57) ( 18.08%) ( 0.31) ( 1) 00:00:07 499MB | total 9264796 ( 28.30, 3.14) (100.00%) ( 0.25) ( 1) 00:00:07 499MB | max depth 2
Diagnostics includes messages from the mtoa plugin, information about the bvh acceleration structures, and plugin loading/unloading info.
00:00:00 493MB | [mtoa.session] Setting export camera to "persp" 00:00:00 493MB | [mtoa] Exporting scene 00:00:00 493MB | [mtoa.extensions] aiOptions Using translator , provided by (). 00:00:00 493MB | [mtoa.translator] defaultArnoldRenderOptions | : Exporting Arnold options(options): 000000002B36F2E0 00:00:00 493MB | [mtoa] [aov beauty] Setting AOV output: filter and driver.
Arnold Support Corner 