Simulating through backburner

[ben_hamburg]

Hey there,

we have a bigger FX job coming our way and are considering stocking up on simulation licenses for our farm.

I´ve used the Phoenix submission menu for 3ds max before and it worked like a charm.

But now I wanna know a bit more about the workflow for using the farm.
I already know, that simulating one simulation over several nodes isn´t possible, so I´m wondering what the best workflow for utilizing the farm would be for these scenarios:

1. I have one simulation in the scene and I want to go through various iterations, changing some settings:
A) Do I simply submit each simulation with different settings to the farm?
B) Whats the best approach of keeping track of those settings? Are´nt they saved near the scene file or some other place? I´d just create a spreadsheet, naming the scene files before submission (SceneX_Viscosity_V001, Scene X_Viscosity_V002) and then add the settings in the spreadsheet.
C) Or could I just clone the simulation grids (including all geometry) and then send them to be simulated in one scene? In this case it might be another idea to simply add text objects near the simulators in the scene, describing the changes of the settings.

2.) I have several simulators in one scene (or 1.C)):
A) Do I simply submit the scene to the farm, as I would do with a single simulator and they get distributed automatically throughout the farm? Or do I need to use a custom script for that?

3.) I wanna simulate over night and get visual feedback in the morning...
A) For most cases, the GPU preview is pretty sufficient, but I can´t seem to get it to save out the preview files. Also this probably doesn´t work, if I simulate, if I simulate using the farm, right? And GPU preview for Liquids (and thus the option to save out GPU preview while simulating) isn´t possible anyways, right?
B) How do I go about rendering a preview for scenario 01 and 02? I know there is an option in the submission script, but does that mean the frames are being rendered only after the whole simulation is done, or after every frame is simulated, it gets automatically sent of for rendering?
For example: I might have 4 nodes simulating and another 4 nodes waiting to render...
C) Do you by chance have a script, that creates a playblast after the simulation is done, in cases where rendering would take too long?

Thanks in advance!

[Svetlin.Nikolov]

Hey,

The Backburner submission for 3ds Max is a bit different than Maya, so here are the 3ds Max specifics:

- At the moment you hit submit, Max automatically copies the scene in its current state (I think it does not even force a action on the original - even an unsaved scene can be sent). The copied scene is sent to one Backburner machine (handled automatically by BB), locally or on the network. If you are going to experiment with different variations, it's a good idea to rename the scene before sending it, so you'd know what's happening in each parameter variation. Having several simulators in the same scene is possible, but you need to sequence them to start after one simulator finished - there is a ready template script in the Phoenix Simulation rollout -> Script you need to uncomment and replace the name of the next sim. However, the problem with that is that you gotta wait for the whole thing to finish before you can see what's going on.

- We gotta do a simple interface for varying parameters and getting back images in an organized way, but for now you have to do all of that manually.

- Another important thing that will affect how thing happen when you submit is that since Backburner is not meant to do anything else but to render a scene, the Phoenix simulation happens as a pre-render operation, so rendering has technically already began. This is why there is no progress, and this is why it might not be possible to render a playblast. The GPU preview works only for volumes, so there will be nothing but the Phoenix volume there, and no Phoenix meshes neither. The classic GPU preview that you can enable as a separate viewport is the one that can save images during simulation and you will have only the Phoenix volume in them.

- If this wasn't a Backburner simulation you can enable rendering after each simulation frame, again via the Phoenix script - I think there is a template code for that in the Phoenix script as well. You just gotta call render in the frame end Phoenix callback. However, again since rendering has already began in Backburner mode, I don't think this will be possible for submitted scenes.

Hope this info is useful Cheers!

[ben_hamburg]

Hey Svetlin, thanks for getting back quickly.

I think as far as I have understood, my best option now would be to:

1. Submit several scenes per variation, so they can be simulated simultanously via backburner.
2. Untick "Run only the Simulation and do not Render" (make sure render settings are appropriate for preview quality).

3. If I have several simulators in one scene (like several independent explosions), I can sequence them by using the script accessible in the simulation rollout, BUT this will only simulate all the simulations in the scene, and NOT distribute the simulations throughout the farm, right?
Ideally I would be able to select each simulation and send it to backburner using the submission menu, or is that already how it works?

Pity the render after each frame doesn´t work via backburner...

I wish autodesk would finally update backburner, its just still such a pain in the *** and I don´t wanna keep adding plugins and external tools because of lacking features...Phoenix excluded of course....

[Svetlin.Nikolov]

Indeed, this is correct.

Also, yes - the selected simulator will be submitted if there are many simulators in the scene

[ben_hamburg]

Ok cool, so everything should work just fine and dandy... Thanks again!