Run script in Command Line tools with Python

[kiryha]

I have a render.cmd file with a list of hip files to render:

mread P:/PROJECTS/NSI/PROD/3D/scenes/RENDER/000/SHOT_010/RND_E000_S010_001.hiplc
render -f 1 2 -V /out/RENDER
mread P:/PROJECTS/NSI/PROD/3D/scenes/RENDER/000/SHOT_020/RND_E000_S020_001.hiplc
render -f 1 2 -V /out/RENDER

If I open hcmd.exe and run:

hscript render.cmd

I get all my shots rendered. 

The issue is that I can't get it working with Python, currently able only run Command Line Tools 

import subprocess
cmdTools = '"C:/Program Files/Side Effects Software/Houdini 17.0.459/bin/hcmd.exe"'
subprocess.call(cmdTools)

but have no idea how to execute <hscript render.cmd> later...

[vtrvtr]

Is there a reason you're not rendering using python directly? You can check inside $HFS/bin/hrender.py or render.py for some examples. If your usage is simple, those scripts would be enough for you to use directly

[kiryha]

Thanks, will check them! I did not think about rendering multiple hip files from that perspective, went with first what comes to my mind.

[vtrvtr]

If you want to render the files sequentially, you can do the same you did in that .cmd, but in python. Something like

hou.hipFile.load(file1)
rop = hou.node(path_to_rop)
rop.render(args)

hou.hipFile.load(file2)
rop = hou.node(path_to_rop)
rop.render(args)

...

If you want to to spawn new processes to render your files, you can call hrender using subprocess

subprocess.Popen([path_to_hython, path_to_hrender, hrender_args]) 

And, of course, you can write a specific custom python script to suit any other needs

 

 

[kiryha]

For the first case, I need to import hou module in standalone Python. This is not working:

import sys
sys.path.append('C:/Program Files/Side Effects Software/Houdini 17.0.459/houdini/python2.7libs')
import hou

For the second, can you, please, provide examples of arguments (path_to_hython, path_to_hrender, hrender_args)?

Mine is not working...

import subprocess
cmdTools = '"C:/Program Files/Side Effects Software/Houdini 17.0.459/bin/hcmd.exe"'
batch = 'hscript P:/RENDER/render.cmd'
subprocess.call([cmdTools, batch])

 

Edited April 22, 2019 by kiryha

[vtrvtr]

Sure, here's a hip.

The code is all inside the pythonscript node. It's the following:

import os.path as op
import subprocess

hython_path = op.join(hou.expandString("$HFS"), "bin", "hython")
hrender_path = op.join(hou.expandString("$HFS"), "bin", "hrender.py")
hip_path = hou.hipFile.path()

subprocess.Popen([hython_path, hrender_path, "-e", "-d", "mantra1", hip_path])

As for importing hou, it's not very straight forward. Besides adding the path to the .py file to your current python path, you need to also add the $HFS/bin folder to your PATH variable in order to correctly import the custom houdini C libraries. As described here http://www.sidefx.com/docs/houdini/hom/commandline.html
  

 

subprocess_hython_odf.hip

[kiryha]

If I load and render file via Python directly:

hou.hipFile.load(file1)
rop = hou.node(path_to_rop)
rop.render(args)

Does it use the same amount of memory as in the case with hscript? As far as I understand you need to load hip file anyway, but if you load it in Houdini it may take a lot of resources to draw the scene in viewport...
 

[kiryha]

Ok, build a tool to render a list of HIP files without Hscript and batch files, via Python Directly.

 

 

Edited April 26, 2019 by kiryha

[Outlawed]

You can write a .py file to load a hipfile, set render frame ranges etc, and execute the ROP  ( pressButton() command ).

Save that .py file on disk, then just run:

hython /path/to/your/file.py

 

Hython is the non-gui python version of Houdini.  Just like how hbatch is the Hscript non-GUI version of Houdini.

[berkninan]

To call an external command in a Python script, use any of the following methods:

• subprocess.run() //Python 3.5+ only.

You can get the stdout, stderr, the "real" status code, better error handling, etc...

• os.system()

 It passes the command and arguments to your system's shell.

• subprocess.call() function
• subprocess.Popen Class
• os.popen() function