Since the plug-in dynamically changes the names of parameters to match with ISF inputs, it raises an error when you try to retrieve the value by expression.

An expression like this:

const d = thisLayer.effect("Polar Displacement")("Distance");

triggers an error with the message: ”Error: property or method named 'Distance' in Class 'Group' is missing or does not exist.”.

First, let me thank You for creating and sharing GLSLCanvas!

I've tried it with two versions of After Effects. AE CC 2017.2 (14.2.1.34) - loads and renders some of shaders from Book of Shaders that I've tried. So far no crashes, performance is ok (just a little choppiness while adjusting parameters in plug-in UI).

AE CC 2018 (15.0.0, build 180) - after attempting to load shader via "Load Shader.." AE crashes, same if I just add GLSLCanvas to empty solid and move playhead. Few times it even froze my whole system (not a kernel panic, just complete freeze and lots of artefacts). I also tried to change AE renderer from Metal to Software Only, same thing. Crash report: AE_2018_GLSLCanvas_CRASH.txt

I've compiled Your plugin on MacOS 10.12.6 & XCode 9.2 (9C40b) and used latest AE SDK.

Because expressions cannot refer to an ISF parameter by name as it changes dynamically, displaying the ISF parameter's index would be helpful for users to write expressions referring to them consistently.

Also, users can hide the indices by toggling "ISF Option.." to simplify the UI display.

 // This expression will be broken after reloading the project
effect("ISF")("Label of input")
// This way of referring ISF parameter would work unless the order of ISF inputs does not change
effect("ISF")(12) 

The plug-in currently resets all of the inputs to defaults when you even update even a single character of the shader. So it'd be useful to find a pair of parameters whose names and types are equivalent, between old and new ISFs, and carry over the values.

Not sure if this is planned or not, but would be really nice to see this get Windows support! Looking at the source with my limited knowledge of cpp, I think the file open/save dialogs and such are the only parts that require macOS, but maybe there's more to it I'm not aware of.

At the moment, the 'Reset' label right to the name of effects refreshes not only inputs but also the imported shader itself. So it would be nice to add a 'Reset to Default' button under ISF options so that users can only reset the value of ISF inputs.

As discarding the 'Use Layer Time' checkbox, it'd be useful if the remaining 'Time' slider automatically refers the layer time that the effect is applied.

Since PF_AD_PARAM only supports non-expression values as a default, I tried to use AEGP suites to modify a parameter like the below code at the timing PF_Cmd_SEQUENCE_SETUP has called:

// Set the default expression to parameters
AEGP_EffectRefH effectH = NULL;
AEGP_StreamRefH streamH = NULL;

ERR(suites.PFInterfaceSuite1()->AEGP_GetNewEffectForEffect(G_my_plugin_id, in_data->effect_ref, &effectH));
ERR(suites.StreamSuite5()->AEGP_GetNewEffectStreamByIndex(G_my_plugin_id, effectH, FILTER_TIME_ID, &streamH));
ERR(suites.StreamSuite2()->AEGP_SetExpressionState(G_my_plugin_id, streamH, true));
ERR(suites.StreamSuite2()->AEGP_SetExpression(G_my_plugin_id, streamH, "thisLayer.time"));
    
if (effectH) ERR(suites.EffectSuite3()->AEGP_DisposeEffect(effectH));
if (streamH) ERR(suites.StreamSuite2()->AEGP_DisposeStream(streamH));    

But it raises an error, which says ”internal verification failure, sorry! {child not found in parent} (20::0)”. Does any guru know how to handle this?