ktoa ArnoldMarerialXBake issue

[Anonymous]

Hi,

We are using 'ArnoldMaterialXBake' in a pipeline as a publishing tool to export materialX files from Katana.

(using ktoa-3.2.# / arnold-6.2.#)

https://docs.arnoldrenderer.com/display/A5KTN/ArnoldMaterialXBake

We are using node's 'bake()' method in order to automate the export process.

We are having an issue where it seems impossible (or we just don't know how) to know when the 'bake' process ends, while it seems to process in a different thread then the current one.

Here's a snippet as an example of what we are doing...

node = NodegraphAPI.GetNode('ArnoldMaterialXBake')
filepath = '/tmp/tmpT4ev0n/test.mtlx'
node.getParameter('saveTo').setValue(filepath, 0)
node.bake()
print 'BAKE PROCESS START---' 
i = 0
while not os.path.isfile(filepath):
    i += 1
    time.sleep(0.5)
print 'File exists, elapsed seconds: ', i/2

Would result in;

BAKE PROCESS START---
File exists, elapsed seconds:  4.0

Is there anything we could do in order to access when the `bake()` process ends?

ie; Other then fetching if the file exists in a while loop.

Thanks

[Stephen.Blair]

We already answered this on your Slack channel...was that answer no good?

[Anonymous]

oh, sorry. I haven't been noticed about that (slack channel).

[Stephen.Blair · Accepted solution]

bake should be running synchronously
from SuperTools/ArnoldMaterialXBake/v1/Node.py

        # Run the export!
        log.info('Exporting MaterialX file to %s' % saveTo)
        from Katana import RenderManager
        settings = RenderManager.RenderingSettings()
        settings.asynch = False
        RenderManager.StartRender('materialXRender', node=renderNode, settings=settings)

[Stephen.Blair]

Hi @Jonathan

bake is supposed to be synchronous (see the answer below), so if it isn't, we have a new bug...

[Anonymous]

I've tested your snippet and seems like it does exactly what we were looking for. Thank you.

[Anonymous]

Thanks Stephen, this seems to work fine!

Just to mention, it still seems that the bake() operation is necessary here, I do not know if it's intended or not...

As an example, I made a simple scene with 4 primitive, each assigned with a different material.

settings = RenderManager.RenderingSettings()
settings.asynch = False

mtlxNode = NodegraphAPI.GetNode('ArnoldMaterialXBake1')
saveTo = mtlxNode.getParameter('saveTo')
rootLocation = mtlxNode.getParameter('rootLocations.i0') 

for i in range(4):
    path = '.../tmp/primitive{}.mtlx'.format(i)
    saveTo.setValue(path, 0)
    rootLocation.setValue('/root/world/geo/primitive{}'.format(i), 0)

    # mtlxNode.bake()
    RenderManager.StartRender('materialXRender', node=mtlxNode, settings=settings)
    print 'done ---', os.path.isfile(path), path

Would not output anything and result in;

done --- False .../tmp/primitive0.mtlx
done --- False .../tmp/primitive1.mtlx
done --- False .../tmp/primitive2.mtlx
done --- False .../tmp/primitive3.mtlx

Unless I uncomment the mtlxNode.bake() line. In this case, all 4.mtlx files would render and output as expected.

Does it seem like bug or the normal behavior?

thanks,

Jonathan

[Anonymous]

Thanks Stephen for the quick answer.

That snippet you provided seems to work fine.

However, it still seems the bake() operation is necessary here, along with the RenderManager.StartRender().

I do not know if it's intended or not, made an example below.

thanks again,

Jonathan

[michael.farnsworth]

The bake() is actually what's running the render internally, so you shouldn't need your own call to RenderManager.StartRender(). The bake call should run a synchronous render and not return until it is complete, and if it returns before then that's a bug we should fix.

[Anonymous]

Thanks for having a look.

From the 1st snippet I posted, can you validate you have the same results?

ie;

node.bake()
print 'BAKE PROCESS START---' 
i = 0
while not os.path.isfile(filepath):
    i += 1
    time.sleep(0.5)
print 'File exists, elapsed seconds: ', i/2

Would run an asynchronous render and therefore would print many iterations before the render finishes it's process (and mtlx file would not be available before the end process).

Should I create a bug ticket somewhere or it's already registered on your end?

thanks,

Jonathan