Plug-ins unable to set value of parameters whose AEGP_DynStreamFlag_HIDDEN flag is set

[FxFactory]

After Effects ignores any changes a plugin makes to a parameter’s value during certain commands, if the parameter in question happens to be hidden in the UI by virtue of having its AEGP_DynStreamFlag_HIDDEN flag set.

This bug poses a rather big problem for many of our products, since users are never guaranteed that applying one of the built-in presets will succeed. This should be clear by following the Steps to reproduce below.

Steps to reproduce:

- Install the most recent version of FxFactory from our website: https://fxfactory.com/download/  

- Download the FxFactory plugin available through this link: https://files.fxfactory.com/beta/aegpdynstreamflaghidden-1.0.0.zip 

- Once the download is complete, unzip the file and double-click it to have the "AEGP_DynStreamFlag_HIDDEN" plugin be ready for testing in After Effects. The product will be visible in FxFactory as such:

- Launch After Effects

- Open an exising Comp, and apply the "AEGP_DynStreamFlag_HIDDEN Bug" plugin found under the "AEGP_DynStreamFlag_HIDDEN" category:

- Notice that the plugin has its own Presets parameter: 

- Each of the two built-in presets has a Thumbnail. That thumbnail shows you what you’re supposed to see once all parameter values in the preset have been applied. Select the first preset, which should cause all three circles to become filled (rather than stroked) and the Add blend mode to be used:

- As the plugin applies the preset, notice that After Effects has only allowed certain parameter value changes to occur. The blend mode has been changed to Add, but the circles are still Stroked:

Why did After Effects ignore some of the changes? After the RYGCB preset is applied, the Shape is still Stroked:

- The bug is therefore as follows: the plugin has set the parameter value for *all* parameters in the preset, making sure to set the PF_ChangeFlag_CHANGED_VALUE flag, but After Effects simply ignores any such changes if the parameter in question happened to be hidden, i.e. if the parameter had its AEGP_DynStreamFlag_HIDDEN flag set to true.

Workaround:

No workaround seems to be available. Even if the plugin sets the AEGP_DynStreamFlag_HIDDEN flag to false just before changing the parameter’s value, this is not enough. It appears that AE will only respect the value change if the parameter had been visible prior to to the invocation of our plugin to handle PF_Cmd_EVENT.

For comparison, you can try the same exact plugin running in Premiere Pro:

- Locate the same effect:

- Apply it to a clip and select the same preset:

- Notice that in Premiere, all three circles are correctly set to Filled, and the Add blend mode is used.

Additional notes:

This problem has been there for a while (first filed through Pre-release website as #3568517).

[jenkmeister]

I've logged this into our bug system for investigation.

[octaviosa]

And I just lost almost a day of work trying to understand why I couldn't change my parameter... This is almost 1 year old, it should have been resolved by now!

As a workaround, if anyone finds himself in the same situation, just use streams.