It seems like no matter how I do it there is no way to have a File import of exr sequences with $F4 in the name. If I type it by hand it works, but it will never work if I set it by python or by a link to another property. The result will always be "cannot find file"

Enivob
Show us what the filenames look like. Does your file contain four zero padded digits?

vfx_complex_01a_12x11_F132.0001.exr

I can make it read the file if I point only at the first so I have 0001.exr in the end. But the second I try to use $F4 then it stops working and it complains that the file cannot be found.

So just to iterate. If I would type this exact string in the file node then it works.
However if I have another node with a string/file property and I copy and paste relative, then it does NOT work.
This is in the img file node, that I try to load for compositing.
Cheers,
Andreas

I'm trying to set a file path property by referencing another property in the scene.

So I have PropertyA which has this file name:
"D:/vf/Library/Tech/Fusion/FusionComplexSetup/FramesFusion/a/vfx_complex_01a_12x11_F132.$F4.exr"

Then I have a File node that references this property.
But it never works. It says cannot find the file. I think that it is the $F4 that causes the problem.
If I link to the file manually it says exactly the same as the file above so the spelling is 100% correct.

Any idea what I can do to make it work?

ok. Think I solved it RS Material Builder OpenGL Emission set it to white.

I'm adding some text in the viewport that shows debug information. Problem is if I chose the black background then I cannot see the text because its just black.
What is the best way to have it always lit?
I also render with Redshift so I guess I may have to make an emissive material to render with too.

animatrix_
Any Qt tutorials can help. If you get lost in the syntax, you can look up the PySide2 equivalent code or just PySide2 specific tutorials.

Thanks. I have been meaning to check out Qt. Does it work well within houdini?

Hiya SWest.
I implemented the button approach above. It works quite well. I think only downside I see is that if I give this to my artists they would either have to create this setup every time the want to use the scripts or more likely they would have to open a file with this node in it and copy from it.

I found this tutorial which shows how to add my own Run button. Works I guess but a bit fiddly.

https://www.tokeru.com/cgwiki/index.php?title=HoudiniPython#Make_a_general_python_input_window [www.tokeru.com]

I created a python script node in the obj, but how do I start it??
lets say it says Print("run silly script")

I'm just trying to find a easy way in my scene to have a local script to this scene that I can trigger somehow.
I want to load external libraries and do all kinds of things to my scene.

I can:
1. Create a button on the UI, but I do not want to use that since this script has setup for each scene while buttons are global.
2. use Python Source Editor, But then it starts the script every time I start the level which I do not want
3. I can make a python SOP, but that will run every time I enable the node, so very easy to trigger the script by mistake and I have a large batch script that I run

Frustrating! It feels like they forgot to add the Execute/Run/Play button on the script nodes.

Any ideas where best to place scripts like this

Thanks that is helpful. I still have a few issues with the beauty pass
For example it will still render the objects with visible edges if that was set in the viewport (which is normally what I have while working). But yes, it fixed the background and got rid of gizmos which is useful.
One weird thing is that the lighting is much darker with the beauty pass. Hmm, I notice mplay looks fine, but the jpg that I save are darker when I use the beauty pass. Not sure why

I have been trying all day to set the viewport background to black and disable the grid from Python.

I got this far, so I managed to get the viewport and I set it to dark, but nothing happens.
Any ideas?
What I try to do is setup the scene so its better before generating a flipbook.

####To get the viewport
a = hou.ui.paneTabOfType(hou.paneTabType.SceneViewer)
b = a.viewports()
tviewport = b #this will get the perspective viewport
tviewport.home() #will focus it home
tview_settings = tviewport.settings()
tview_settings.setColorScheme = hou.viewportColorScheme.Dark

What is the best way to create a UI for a python tool in Houdini?
I have not found any tutorials. Basically a window with text and numbers that the user can run before starting the tool.

Cheers,
Andreas

I would like to build a library with python functions that are available in all Houdini scenes.
Any idea on how to do this?

What I did setup the PYTHONPATH environment pointing to a folder, then I created a python file there vf.py
I can now import this from the Python Shell.
One big problem though if I change the code for this vf.py file it will not register in Houdini until I restart.

That means every time I change the script I need to restart which is not great.
I just cannot figure out a good workflow to work with python in Houdini yet.

BabaJ

SWest
Just storing it in an editor will vanish as you noticed.

Actually, it is saved - but only in the hip file in which it was created. New instances of Houdini won't have it.

The odd thing happeneing to me and my collegue is that it is saved sometimes. So I can open the file next day and then I have lost what I wrote in the evening. Not sure what is going on.

Thanks
If I put it in the shelf and open in external editor I see that its putting the shelf in the temp folder. Is that right, that does not sound like a good place to save the code.

I had this happen a few times. I write code in the Python Source Editor, then I restart Houdini and all my changes are gone.
Just lost last evenings coding which is not great.

Am I doing something wrong? What would be a better way of writing the code? I downloaded pycharm, but not sure how to integrate it in Houdini.

Currently what I do is I write my functions in Python Source Editor and then I call functions in the Python Shell which is a bit primitive.

Nice idea Lucap1, will look into it.

The way I solved it was I wrote a Python script that triggers the different stages. The good thing is that then I can also time each stage. I always think that Houdini gives too few stats so I just gather them myself now. Calculation time, particle count etc.

animatrix_
You can also try slicing your sim and run in parallel, but memory could be a bottleneck depending on how much you have.

Aha, so you mean slicing the sim and running 2 sims at the same computer? Or just to do it over multiple computers?

Hiya,

Just some quick benchmarks for flip simulations.
AMD 3990X 64 core
AMD 3975WX 32 core Pro.

Benchmark: Flip Sim
Houdini Benchmark Flip scene
Solver. Save to Disk
3975WX 1min17 - 3.96-4GHz SMT ON. 32 cores.
3990X 1min17s 3200MHZ RAM SMT Off. Cpu usage was about 75-80% and speed around 3.6GHz. 64 cores
3990X 1min55s 2133MHZ RAM SMT On. This uses slower memory settings.
3990X 1min43s 3200MHZ RAM SMT On

Comment. 32 Core Pro and 64 core has identical speed for the solver.
This is probably because this step is not that well multithreaded, and the Pro has better memory usage and also a bit higher clock speed. You can also see that disabling SMT (hyperthreadding) increase the sim speed.

Geometry building
3990X 2min25 3200Mhz SMT OFF. This step is at 100% so we can see its a bit faster than the Pro
3990X 2min56s. This used 100% of the cores at 3.5GHz
3975WX 2min43 - pretty much fully core utilisation at 3.8-3.9GHz

Windows 10. Air cooled systems.

I could maybe upload the file for others to test. Its not a very heavy flip, so worth testing higher res of it.
What I ideally would like is that we get 64 core AMD with more modern Zen 4 or similar. Zen 2 which is what 3990x is using is a bit old. In other programs like Terragen the 64 had a bigger advantage than this, about 50% faster than the 32 core.

Hiya
So I have a flip where I have several steps of caching
1. I cache the solver into a file cache
2. I cache the Particle Fluid Surface

Is it possible to trigger these caches with 1 click. Right now I have to cache the first to disk, then wait, and then I can cache the second step.

Even better would be if I could also trigger a render so basically cache 1 and 2 and then render the sequence.

Cheers.