Vray and Arnold not loading/working together within houdini/solaris.

[think_tank]

Hello,

I've been struggling to get vray and arnold to work together in the same houdini build within solaris. I've tried many package configurations as well as .env ones but I do still errors.
Looking around it seems to be a python compatibility issue regarding arnold, vray and houdini. But I've tried explicitly setting vray to the same python version as houdini, arnold and
still got that error (I might be doing that wrongly though).

errors I am getting in houdini versions 19, 19.5

ModuleNotFoundError: No module named 'vfh_py'

full log:



Somehow it does seem like its not finding the QT plugins (seen this on houdini 19.5...) although in the vray.json file I do see a line mentioning:

{ "VRAY_FOR_HOUDINI_APPSDK_BIN" : "${VRAY_APPSDK}/bin" },
{ "QT_PLUGIN_PATH" : "${HFS}/bin/Qt_plugins" },
{ "QT_QPA_PLATFORM_PLUGIN_PATH" : "${HFS}/bin/Qt_plugins/platforms" },


I did try installing Houdini 19.0.720 with both python 2 and python 3 and their equivalent arnold version and setting vray PYTHONPATH to point to the right
python folder but still got those errors, I also tried all of the above but with houdini 19.5.435, 19.5.605 and 19.5.716 and the arnold & vray versions for those but still get
the same errors...

I noticed that the default vray_for_houdini.json gets copied onto the sideeffectssoftware -> houdiniversion -> packages rather than in user/documents/houdiniversion/packages I am guessing
its the same as long as the path to look for package dirs is correct? I ve been changing the first one.

if I uninstall arnold then vray works fine without changing anything and the same if I uninstall vray, arnold works, but we do need to use both on the same build ideally.

Let me know if you have any thoughts as currently we cannot use vray and arnold together with solaris. (OS is windows 10 btw)

Thanks.

[bdancer]

> I noticed that the default vray_for_houdini.json gets copied onto the sideeffectssoftware -> houdiniversion -> packages rather than in user/documents/houdiniversion/packages

Yes, V-Ray is installed globally and it's package file is copied to the system directory rather then user directory, this is correct.

> I ve been changing the first one.

You can't have multiple V-Ray package files (actually, you can't have multiple package files loading the same thing, no matter V-Ray or not).

Also I'm not sure you need to edit anything at all. Why do you need to edit the package file?
How are you loading Arnold? .json? .env? Does it have a package file? If not - why doesn't it have a package file? May be ask at the Arnold forum?
Does Arnold setup modifies PYTHONPATH? Are you modifying PYTHONPATH? How are you appending data to the HOUDINI_PATH?
Error means Houdini can't find our Python modules, which essentially means HOUDINI_PATH value is incorrect.

You could find all the values by using Python shell (os.environ) and debug package loading HOUDINI_PACKAGE_VERBOSE=1.


What I've did to test this:
1. vray_adv_61009_houdini19.0.561_6df9f0b_22504
2. htoa-6.1.2.0_re046489_houdini-19.0.589.py3_windows
3. Houdini 19.0.561

Default installed vray_for_houdini.json, Arnold setup with houdini.env:

ARNOLD_HOME="C:/install/houdini/arnold/htoa-6.1.2.0_re046489_houdini-19.0.589.py3/htoa-6.1.2.0_re046489_houdini-19.0.589.py3"

# Setup HOUDINI_PATH
HOUDINI_PATH="${ARNOLD_HOME};&"
​

Absolutely no errors, both V-Ray and Arnold loaded without issues.

Default installed vray_for_houdini.json, Arnold setup with htoa.json (empty houdini.env):

{
    "load_package_once" : true,
    "path" : [
        "C:/install/houdini/arnold/htoa-6.1.2.0_re046489_houdini-19.0.589.py3/htoa-6.1.2.0_re046489_houdini-19.0.589.py3"
    ]
}
​

Absolutely no errors, both V-Ray and Arnold loaded without issues.

[bdancer]

I've tried htoa-6.2.3.2_r6e449ce_houdini-19.5.716_windows and I could confirm Qt errors with it affecting license manager; however Arnold itself loads without issues.
I'll remove QT_PLUGIN_PATH / QT_QPA_PLATFORM_PLUGIN_PATH vars from the V-Ray package file in the next nightly build and make it work without those.

[4n7]

I have a similar issue. Andrei are you able to switch render viewports in Solaris?

I can load V-Ray, along with Karma, Storm, Renderman, 3Delight, Redshift, Radeon, Octane and it works fine displaying shaders in the viewport, same with Arnold along with all the other render engines.

When I have Arnold & V-Ray loaded at the same time the viewport shows grey shaders for all but Karma
I
There's a few other posts on this issues
https://forums.chaos.com/forum/v-ray...nold-is-loaded
https://forums.chaos.com/forum/v-ray...her-houdini-19
https://forums.autodesk.com/t5/arnol...s/m-p/11451491

[bdancer]

Yes, I could switch V-Ray, Karma and Arnold without issues.
Anyway, try tomorrow nightly, I've removed those Qt vars, may be it'll help with your setup.

[think_tank]

Thanks for your answer Andrei, will try to take a look at this as soon as I can. Let me know if you have a nightly build to test when possible please.

Also in regards to your last comment, does that mean that you were able to switch between renderers but that materials worked for all of them respectively?

I mention this because I did notice that despite of the errors above (qt plaform... No module named 'vfh_py') vray and arnold would show in houdini, but vray although geometry had a vray material assigned
would not pick up the material and render with default solaris shader (shaderless), not sure if this is the same issue as you @4n7 though!
Arnold would still render so unless the qc platform and other errors are fixed I guess vray wont work.

As mentioned on my first line, I will try to find a bit of time to look into what you mention in your comments Andrei about python versions and how to see which is using.

[bdancer]

> Arnold would still render so unless the qc platform and other errors are fixed I guess vray wont work.

V-Ray (nor any other renderer) doesn't "choose" the material - it renders whatever Hydra has resolved for it.
If Arnold messes smth up for V-Ray - we can't do anything about it.

[4n7]

I tested with the nightly, didn't change anything, same issue.


I'm using a simple scene, torus with Material Library node containing a collect node with the various material assignments


I've compared the Houdini envs being set, main difference seems to be

AOV <reName>
HOUDINI_DSO_PATH C:/Program Files/Chaos Group/V-Ray/Houdini 19.5.605/vfh_home/dso_py39;&
HOUDINI_GALLERY_PATH C:/Program Files/Chaos Group/V-Ray/Houdini 19.5.605/vfh_home/gallery;&

other than that everything is ARNOLD/VFH specific, not sure if the AOV option is relevant or where that is set?

[bdancer]

> I'm using a simple scene, torus with Material Library node containing a collect node with the various material assignments

Could you please send it to me so that we are on the same page?

[4n7]

This file has a simple set-up with materials for V-Ray, 3Delight, Redshift, Renderman & Arnold.

What I did notice in the newer version is that when both V-Ray & Arnold are loaded, Arnold now shows in the viewport, V-Ray and everything else are grey

[bdancer]

V-Ray renders pink for me no matter if Arnold is activated or not:


Karma renders cyan no matter if Arnold is activated or not:


Arnold renders bluish material:


Both are deployed using package files.
Houdini 19.5.716.

[4n7]

If I set my packages file like yours it doesn't load properly

{
"load_package_once" : true,
"path" : [
"C:/Users/antg/htoa/htoa-6.2.2.0_rf4b9c5b_houdini-19.5.605/htoa-6.2.2.0_rf4b9c5b_houdini-19.5.605"
]
}

If I load it another way it loads Arnold as usual but greys texture when running alongside V-Ray

{
"load_package_once" : true,
"enable": true,
"env": [
{
"HOUDINI_DSO_ERROR": "2"
},
{
"HOUDINI_PATH": "C:/Users/antg/htoa/htoa-6.2.2.0_rf4b9c5b_houdini-19.5.605/htoa-6.2.2.0_rf4b9c5b_houdini-19.5.605"
},
{
"PATH": "C:/Users/antg/htoa/htoa-6.2.2.0_rf4b9c5b_houdini-19.5.605/htoa-6.2.2.0_rf4b9c5b_houdini-19.5.605/scripts/bin"
}
]
}

19.5.605 py39 in Windows 10, but I've also tested this on linux/win11 with older versions and different py versions with the same issue.

is this a py39 thing? I think the version you are using is the py37 version of Arnold, confusingly the 19.0 download are py2 standard and py3 (3.7) with the extension on the download
https://arnoldrenderer.com/download/...udini/6.1.2.0/
as 19.5 dropped py27, the standard download is py39, optional py37
https://arnoldrenderer.com/download/...udini/6.2.2.0/

I'm not alone here as there's plenty of other users having similar issues
https://forums.autodesk.com/t5/arnol.../td-p/12229280

[bdancer]

> is this a py39 thing? I think the version you are using is the py37 version of Arnold

No, I'm not, all are Python 3.9.
If remote session is an option for you please drop me a line to the email in my signature.

{
   "load_package_once" : true,
   "enable": true,
   "env": [
    {
      "HOUDINI_DSO_ERROR": "2"
    },
    {
      // THIS IS POTENTIALLY WRONG - use "path" property.
      "HOUDINI_PATH": "C:/Users/antg/htoa/htoa-6.2.2.0_rf4b9c5b_houdini-19.5.605/htoa-6.2.2.0_rf4b9c5b_houdini-19.5.605"
    },
    {
      "PATH": "C:/Users/antg/htoa/htoa-6.2.2.0_rf4b9c5b_houdini-19.5.605/htoa-6.2.2.0_rf4b9c5b_houdini-19.5.605/scripts/bin"
    }
]​​​​

There is no need setting HOUDINI_PATH in package file, package file has specific entry for plugin "home", so the json should be:

{
  "load_package_once" : true,
  "enable": true,
  "env": [
      { "ARNOLD_HOME" : "C:/Users/antg/htoa/htoa-6.2.2.0_rf4b9c5b_houdini-19.5.605/htoa-6.2.2.0_rf4b9c5b_houdini-19.5.605" },
      { "PATH" : [
        "${ARNOLD_HOME}/scripts/bin"
      ]},
  ],
  "path" : [
    "${ARNOLD_HOME}"
  ]
}
​

[bdancer]

So, with the help of 4n7 we've figured out that Arnolds startup somehow messes up internal PYTHONPATH.
The current workaround is to explicitly add path to V-Ray Python modules to the PYTHONPATH, e.g:

       { "PYTHONPATH" : [
            { "method": "append", "value": "${VRAY_APPSDK}/python" },
            { "method": "append", "value": "${VFH_HOME}/python3.9libs" } // ADJUST PYTHON VERSION IF NEEDED!
       ]},​

[4n7]

Thanks bdancer , very much appreciate you taking the time to connect and sort this issue, both apps now working as expected in the viewport

Looks like this change in the json file gets it back on track

think_tank I think this change should fix your issue, it looks like we get the same error (sorry I hijacked your thread)

{ "PYTHONPATH" : [
{ "method": "append", "value": "${VRAY_APPSDK}/python" },
{ "method": "append", "value": "${VFH_HOME}/python3.9libs" }
]},