Inspiring

Question

HELP: How to sync a plugin parameter to a layer transform's position ?

Forum|Forum|3 years ago
January 24, 2023
3 replies
1669 views

Hi everyone,

I have written a plugin that checkouts a layer (PF_ADD_LAYER) and displays it on the layer the effect is applied to. I've also made it possible to control the position of the displayed layer through controls on the effect's UI (PF_ADD_POINT for the position for example, PF_ADD_ANGLE for the rotation etc).

My question is: how can I automatically sync these transform parameters (position, rotation, scale...) to the selected source layer's transform data, so the checkout layer is displayed at the same position as the original layer ? Yes it is possible to do it through the traditional After Effects' expressions. But I was looking for a way to do it automatically within the plugin.

SDK

This topic has been closed for replies.

S

shachar carmi

Community Expert

short answer: highly unrecommended.

long answer:

well... there no "link" method (besides expressions, as you have said). you can check the values on idle time and then copy them if changed, but that won't work during rendering. it would also be problematic with undo/redo as the user may be aditing the target layer...

my suggestion is to add a drop down with 2 options:

1. manual controls

2. follow original layer

if 1 is seleted, show the controls. if 2 is selected hide the controls and get the values from the original layer.

A

Alex274279575doxAuthor

Inspiring

Thanks a lot for your answer. I've managed to implement the first option, however I struggle to implement the second one:

I am able to get the selected source layer's transform data (position, rotation...) using the AEGP_SuiteHandler methods. However I am not sure how to watch for changes on this data. I tried creating another thread and check the values each second. But it doesn't work and I don't like this solution. Is there another cleaner method to do it?

S

shachar carmi

Community Expert

lookup GuidMixInPtr.

it's means of telling AE during SmartPreRender calls what external data (that is not directly referenced by the effect using traditional methods) this render relies on. AE calls pre-render whenever there's a change in the comp, to let effects report if they were relying on some external data that might have changed.

if the resulting GUID differs from the one AE has associated with the cached frame, AE invalidates the cahce and re-renders.

you can factor anything you like into the GuidMixInPtr function, including the transform data of some random layer.

James Whiffin

Legend

Are you wanting your plugin's transform params to be synced to your original layers transforms? The only way is by expressions since params can't be updated on the fly through c++ plugins.

Mylenium

Legend

You probably simply need to query the default property streams, instanciate them and weave them into your matrices.

Mylenium

Sign up

To post, reply, or follow discussions, please sign in with your Adobe ID.

Sign in to Adobe Community

To post, reply, or follow discussions, please sign in with your Adobe ID.

Scanning file for viruses.

This file cannot be downloaded