Here’s a setup that renders cryptomatte to one Render Product, and the lighting AOVs to another Render Product.
This uses the new input port on the Arnold Render Settings LOP.
This results in the following scene graph:
which renders two EXRs
00:00:09 3152MB | [driver_exr] writing file `C:/Users/blairs/Support/houdini/beauty.0001.exr'
00:00:09 3152MB | [driver_exr] writing file `C:/Users/blairs/Support/houdini/crypto.exr'First, set the Arnold log verbosity to Info (typically, Info is more than enough).
Then open the Log Viewer.
Render something. Then in the Log Viewer, switch to text-only view.
Select All (Ctrl+A) and Copy (Ctrl+C) and paste into a text file.
Here’s the package file I’m currently using.
{
"load_package_once": true,
"env":
[
{"HTOA_PACKAGE": "HTOA"},
{
"HTOA_INSTALL_PATH" :
[
{"houdini_version == '20.0.506'": "D:/programs/htoa/htoa-6.2.5.0_re21740b_houdini-20.0.506/htoa-6.2.5.0_re21740b_houdini-20.0.506"},
{"houdini_version == '20.0.547'": "D:\programs\htoa\htoa-6.2.5.1_r539f2c5_houdini-20.0.547\htoa-6.2.5.1_r539f2c5_houdini-20.0.547"}
]
},
{"HTOA_STARTUP_LOG": 3},
{"HTOA_MAKETX_WORKERS": 30},
{"HOUDINI_PATH": [
{
"value": "$HTOA_INSTALL_PATH",
"method": "prepend"
}
]
},
{"HOUDINI_TEXT_CONSOLE": [
{
"value": "1",
"method": "append"
}
]
},
{"HDARNOLD_DEBUG_SCENE": [
{
"value": "C:/temp/hdarnold_debug.ass",
"method": "append"
}
]
},
{"HOUDINI_SPLASH_MESSAGE": "Loading HtoA: $HTOA_PACKAGE"},
{"PATH": [
{
"value": "$HTOA_INSTALL_PATH/scripts/bin",
"method": "prepend"
}
]
}
]
}
Append mode (aka check-pointing) allows you to restart an interrupted render, and render just the remaining tiles. Those tiles are “appended” to the tiles that were rendered before.
If you’re using the Arnold Render Settings LOP, the Append check box is under File Output > Driver Options. You have to enable Arnold product type for any of the driver options to work.
If you’re using the regular Render Settings LOP, you can turn on Append mode in the Render Product LOP. Don’t forget to change the Product Type to arnold.
Or, “things that happen when you use single-user licensing on a render node” 😉
In this case, a Houdini command-line render with Arnold (HtoA) failed because the AdskLicensingAgent failed to start.
--------------------------- AdskLicensingAgent --------------------------- This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem. Available platform plugins are: minimal, offscreen, webgl, windows. --------------------------- OK ---------------------------
After AdskLicensingAgent crashed, the render would continue, but license authorization would fail:
00:00:00 148MB | authorizing with license manager: user ... 00:00:31 153MB WARNING | rendering with watermarks because of failed authorization: 00:00:31 153MB | [clm.v2] timeout before callback was called
Using Process Monitor, I saw (as expected) that the problem was that the AdskLicensingAgent was loading Qt platform plugins from Houdini:
The solution? Set QT_QPA_PLATFORM_PLUGIN_PATH to point to the AdskLicensingAgent\platforms folder.
set QT_QPA_PLATFORM_PLUGIN_PATH=C:\Program Files (x86)\Common Files\Autodesk Shared\AdskLicensing\Current\AdskLicensingAgent\platforms
If you have a problem like this:
that is almost always because the environment (PATH and HOUDINI_PATH) is not set up correctly for HtoA and Houdini.
First, how to do you start Houdini? Don’t double-click on a hip file, because the Houdini environment won’t be set up correctly.
Second, what’s your houdini.env look like?
You want something like this (PATH is for Windows only):
# htoa config start
PATH = "$PATH;C:/arnold/htoa/htoa-5.6.0.0_r370661f_houdini-18.0.597/htoa-5.6.0.0_r370661f_houdini-${HOUDINI_VERSION}/scripts/bin"
HOUDINI_PATH = "C:/arnold/htoa/htoa-5.6.0.0_r370661f_houdini-18.0.597/htoa-5.6.0.0_r370661f_houdini-${HOUDINI_VERSION};&"
# htoa config endThird, check Help > About Houdini > Show Details
You want to see the HtoA location at the start of HOUDINI_PATH
If you have other renderers and plugins, I would remove all other plugins from HOUDINI_PATH, get HtoA working, and then put the other stuff back.
If you need more help, please send support your houdini.env file (or json package if that’s what you’re using) and the Houdini info from Show Details.
To use the Arnold Denoiser (noice) on light groups, you need to have variance AOVs for the light group AOVs.
There are two ways to associate a variance AOV with a light group AOV.
C.*<L.'red'>
Then to denoise the AOVs:
noice -i "light_group_denoise.0001.exr" -o C:\temp\denoised.exr -pr 3 -sr 3 -l red -l RGBA_green
noice 7.1.1.0 [72784a51] - the Arnold denoiser
Using 8 threads.
Loading images...
Loading file "light_group_denoise.0001.exr".
Using feature AOV 'denoise_albedo' with filter 'gaussian_filter'
Using feature AOV 'N' with filter 'gaussian_filter'
Using feature AOV 'Z' with filter 'gaussian_filter'
Working with 1 frame at 1280x720
Will denoise AOV "RGBA", using associated variance
Output file will be "C:\temp\denoised.exr"
Will denoise AOV "RGBA_green", using associated variance
Output file will be "C:\temp\denoised.exr"
Will denoise AOV "red", using associated variance
Output file will be "C:\temp\denoised.exr"
Start denoising (patch radius 3, search radius 3, variance 0.5)
Denoising RGBA
Denoising RGBA_green
Denoising red
Finished denoising
Saving image C:\temp\denoised.exr (1280 x 720 x 12)
Add -irgba to that if you want to skip denoising the beauty. Note that with -irgba. the beauty AOV won’t be copied to the output file. Only the denoised AOVs go the output file.
All the AOV, LPE, and layer information that you set up in HtoA goes into EXR metadata.
noice uses that metadata to find the variance AOVs for each AOV. The association may be through the AOVs having the same name, or the AOVs using the same explicit LPE.
The HtoA installer supports silent installs and silent extractions (an install will update houdini.env, an extract does not).
htoa-6.0.0.0_r6c54f59_houdini-18.5.696_windows.exe -h
htoa-6.0.0.0_r6c54f59_houdini-18.5.696_windows.exe [options]
Options:
-?, -h, --help Displays help on commandline options.
--help-all Displays help including Qt specific options.
-v, --verbose Verbose mode. Prints out more information.
--extract Extract installation contents in the current directory.
--extract-to <dir> Extract installation contents in <dir>.
--accept-license Do not prompt for license acceptance in silent mode.
IMPORTANT: By using this option, you accept the end-user
license agreement
--silent Silent installation (no GUI).
For example, this command silently installs HtoA on Windows. The –verbose gives you a log in the command prompt window.
htoa-6.0.0.0_r6c54f59_houdini-18.5.696.py3_windows.exe --accept-license --silent --verbose
Error running pythonrc.py:
Traceback (most recent call last):
File "C:/Users/example/htoa/htoa-5.6.3.0_ra766b1f_houdini-17.5.460/scripts/python/pythonrc.py", line 5, in <module>
import htoa.searchpath
File "C:/Users/example/htoa/htoa-5.6.3.0_ra766b1f_houdini-17.5.460/scripts/python\htoa\searchpath.py", line 7, in <module>
import htoa.dialog
File "C:/Users/example/htoa//htoa-5.6.3.0_ra766b1f_houdini-17.5.460/scripts/python\htoa\dialog.py", line 3, in <module>
from builtins import str
ImportError: No module named builtins
If you see errors like this, it’s because as of HtoA 5.6.3, the builtins module is required. Houdini 17.5 doesn’t include this module (unlike Houdini 18 and later), so you’ll have to install it.
cd "C:\Program Files\Side Effects Software\Houdini 17.5.460\python27" python -m ensurepip --upgrade python -m pip install future
HtoA lets you edit the layer names, and that’s how to generate the variance AOVs for denoising.
Arnold Support Corner 