Sequence_data different in PF_Cmd_RENDER and PF_Cmd_USER_CHANGED_PARAM

[françois leroy]

Hi all!

I have a really anoying issue with in_data->sequence_data and After Effects CC 2015.

I'm storing data in Sequence_data.

The problem is: I don't get the same data in Render and UserChangedParams...

The exact same code works fine with After Effects CS5.5. First, I thought it might be because of the new flattening calls, but I have the same issue even when I first apply my FX and change one parameter value (I don't receive any other call).

Did anyone run into a similar issue? Any solution?

Cheers,

François

[shachar carmi]

hey François! how have you been?

if you see this behavior in cc2015 or later, then that's the big change

everyone was talking about.

the render thread and the UI thread have separate seq data handles, and

they synchronize at very specific occasions.

what is it that you're saving there? perhaps there's a different way to

pass the data, or maybe to force the sync.

[françois leroy]

Hi Shachar, glad you're here! 🙂

In fact, my FX is a particle plugin, and I store previous frame's data, in order not to re-compute everything.

I have 2 types of parameters:

1_parameters that actually modify the physics (I set a Supervise flags on these)

2_parameters that modify only the look of the particles

Then, when I change one of these physics parameter, I get a UserChangedParam call, where I clean up the sequence data to start again from zero...

And of course, for cosmetic changes, I keep my data.

What do you mean by 'force the sync.' ? Is it possible?

Cheers,

François

[shachar carmi · Accepted solution]

try to set PF_OutFlag_FORCE_RERENDER during UserChangedParam. according to

the CC2015 sdk docs this should force a flatten call on the ui thread and

an unflatten on the render thread, syncing the render thread's sequence

data with that of the ui data.

[françois leroy]

Wow, it works!! Thanx a lot, I was totally lost in the new architecture...

I've set PF_OutFlag_FORCE_RERENDER during UserChangedParam.

It does change the behaviour, but not the way I thought...

1_UserChangedParam is called.

I get some sequence_data, different from the one I got in the Render call before. In my case, it's ok, as I don't need to read the data, only to write it... But I wonder how we can do if we want to read it?

I change this sequence_data (resetting it in my case)

2_GetFlattenedSequenceData is called, not less than 5 times (!!!)

3_SequenceFlatten is called

4_SequenceResetup is called

5_Render is finally called and I get the right sequence_data

Is it me, or is it a bit complicated just to pass some data from one call to the other? I mean, flattening 6 times and unflattening 1 more time...

And what about this (from the SDK) :

"Once we have the full set of APIs in place needed to manage render state, we will be able to deprecate FORCE_RERENDER"

I don't really get it... But it works!

Thanks Shachar!

Cheers,

François

[shachar carmi]

yeah...

in cc2015, in order to make AE's UI more responsive, the AE team decided to

create 2 parallel projects, so that the render thread and UI thread could

work separately.

the 2 projects are synced on numerous occasions. HOWEVER, data only travels

from the UI copy to the render copy, and not the other way around.

if you must pass data from the render thread to the ui thread (and luckily

you don't), then a lot of shenanigans need to happen...

yes, the 7 flattens are rather striking, but in the future

the PF_Cmd_GET_FLATTENED_SEQUENCE_DATA should work globally for the plug-in

and not just for custom UI events. (at least i think that's the plan)

as for the deprecation of FORCE_RERENDER, i think you can force the sync

using the GUID calls, but i'm not sure.

i plan on dealing with that as it comes...

[françois leroy]

A lot more fun to come! 😉

[shachar carmi]

weeeeeeee!

[gabgren]

hi shachar , @francois !

there is still no way to update UI sequence_data from render function ?

[shachar carmi]

nope, and that's by design. so don't rely on that to change any time soon...

however, global data is shared between threads. perhaps that could solve

your render-to-ui-thread-communitaction needs.