Ship on Ocean Sim Restore After Max Shutdown / Start

[rporter8555]

Greetings!

This is my ship on the ocean simulation after having to shut down max (unplanned) then open again and attempt to restore from the last frame.
I did not have this problem with "Pause" and "Resume". Also no issues with "Stop" and "Restore" as long as the max session stayed active. But when max is shutdown then restarted, the sim is not restoring correctly. Notice the wave or dip which is being created at the leading side of the grid.
I have Output Backup Interval set to 15 for the initial water sim pass.
Using Phoenix 3 and Max 2017.
Any idea why this is happening?



Thanks,
Ron Porter

[Ivaylo Katev]

well, if the last frame is broken, why not using the previous checkpoint, 15 frames ago?

[rporter8555]

Hi Ivaylo!
Yes, thanks. The pictures I posted were taken two frames after the checkpoint, starting with the timeline pointing to the checkpoint even as you suggested. The water level on the leading edge comes back to normal right after the depression event.
I had already deleted from the cache the smaller aur files after the big checkpoint file, then set my timeline to the checkpoint file. Everything at the time looked good so I click "Restore" at that frame and the sim starts up again from that point. Two frames later the depression in the surface leading edge appears, and the depression remains and the ship rides over and through it.
Next experiment, I deleted the failed experiment frame aur files and moved back in the timeline two checkpoints earlier so if the sim wanted to interpolate between checkpoints to pick up the velocity information it could, but the depression wave appeared within two frames.
I have been able to stop the sim and restore with success earlier in this sim. The problem started after having to shut down and restart the computer or even the max session.
Ron

[Ivaylo Katev]

well, in this case i suppose the reason is in the scene, can you try with a new simple scene created from scratch?

[rporter8555]

Yes, I will do that.
In the meantime I thought it would be interesting to see what happens if I let the sim continue running, and maybe this would offer some clues.
Below: Frame 600 before the shutdown and restore.

Below: Frame 950 after the restore.

Below: Frame 1000

Below: Frame 1050

[Svetlin.Nikolov]

Indeed, the restore doesn't seem to play nice. Could you drop the scene to Support so we can clear these out?

Thanks!

[rporter8555]

Thanks Svetlin!

I have new information from the testing.
I created this new scene from scratch using the toolbar setup, 1000 frames, turned off the particle exports, turned on the output grid channel velocity, and set SPF to 1.
Sim runs correct to end with no issues.
Then go back to a middle time and Restore, and the sim works correct as expected.
Then changed SPF to 3 and ran the sim new and complete from start to end. Works correct as expected.
Then go back to a middle time and Restore. Depression forms briefly at leading edge of sim, which causes defective action in the rest of the sim as the grid continues to move forward.

This shows me that using SPF to get better liquid action on the ship is somehow related to the problem. The only way I can get a successful sim is to run from start to end without interruption.
Also, this is not new problem with version 3, I have seen this since several nightly builds in version 2 and never made the connection to SPF.

I sent the scene above to support.
Thanks for your help on this.
Ron

[Ivaylo Katev]

well, as i understand restore works good only with spf=1?

[rporter8555]

Thank you Ivaylo!
Now it is starting to make sense.
I needed to change my SPF to 1 so that each step is saved in cache, also change my timescale to <1 to provide more liquid movement detail for better splashes.
Correct?

[Ivaylo Katev]

if the reason is really the spf, this is a bug and should be fixed. i have memories that restore worked at any spf, so it's still not sure what exactly is happening

[rporter8555]

I hope you are right, since changing the sim timescale would also require me to adjust the sim frame count and ocean travel distance timing as well as shipboard animation timing. Does that also affect velocity settings for foam generation?
Or am I mistaken?

[Ivaylo Katev]

i think yes, only for the foam. the splash generation is related to traveled distance and should be not affected. better wait for a fix, if really this is the problem

[rporter8555]

Thank you so much! I am eager to learn what your team thinks of this. In the meanwhile I will go ahead and work with the timescale as a workaround.
This software is amazing.

[Ivaylo Katev]

why not just avoid restoring? you will modify the scene in a relatively hard way, and i'm almost sure this will take several hours with all the tests until reaching the same result, you can just simulate with no restore, it's not a critical feature.

[rporter8555]

Hi Ivaylo!
I do not disagree. I should get a sim license that can run on one of my render slaves for two or more weeks without interruption, even while I continue dev work on my ship model on my workstation. That is a justifiable cost of using the software for the desired result.
The benefit of the restore feature is not diminished.
Did I mention the software is amazing?
Thanks,
Ron Porter

EDIT: Are separate sim licenses available for sale?
EDIT: Never mind, I found a reseller who has it.