I have redone a tutorial(1) multiple times over on how to set this up. I have a particle system I am bringing into Maya, my particle sim begins at frame 14, and in the viewport, as well as the arnold renderview, it looks and moves like it should. However when I batch render it in Maya, or send to our render farm, it shuffles the frames of the sim around at its leisure, it will go 16,16,14,15,16,22,ect. My cache is in my maya directory and my path is absolute. Anything helps, thank you.





1: https://www.youtube.com/watch?v=GyebOTtke5w [www.youtube.com]

Just to make sure I understand what the problem is:

1. what platform are you on? what version of Maya, what version of Houdini?

2. When you say that it shuffles the frames of the sim around, do you mean that when you look at the rendered frames, there are particles in the render, but the particles correspond to a different cached frame, and the frames may be out of order. Are there some frames that are missing paricles entirely?

3. You're still reading the particles through the maya plugin from the houdini cache - you haven't recached them out of Maya?

4. Is the particle system the only houdiniAsset in your scene? or are there other asset nodes?

5. Are you sending off your batch render from inside maya? Or from the command line? What frame is the file to be rendered saved at? What is the start frame of your nParticle system? Ignoring the render farm for now, do you have an interactive Maya running at the same time as your batch render is running on the same machine?

4. If you batch render a single frame (somewhere in the middle of the cached range from the command line with no other maya process having the same scene open do you get the correct particles? And does it render fast enough that you can tell it's not resimming.

6. What are your session preferences? If you're running in 17.0, you're forced to run out of process - so are you doing named pipe/autostart, named pipe/manual server, or tcp socket? Just thinking about how many HARS servers you have running on one machine at the same time? Or whether more than one process is trying to connect to the same HARS server to read the cache for a different frame at the same time?

7. I have to admit that I don't actually know that much about batch rendering in arnold in Maya - does a batch arnold render run out of a batch Maya, i.e. evaluate the frame in maya and then render? Or does it do its own native recaching? Does it spawn a single process for a sequence of frames? Or does it spawn off a bunch of processes? You can probably see where I'm going here with multiple processes and HARS server issues…

8. Could you try batch rendering sequence of frames with the Maya software renderer instead just to eliminate any Arnold specific issues (without motion blur, just in case that's an issue as well)