Controlling Model Item Opacity Using Toggle Button

I found a solution to this. I think that it should be seen as just a workaround because it requires coding, would be great to have this done coding free because opacity is crucial to AR applications in my point of view.

Steps of the solution:

If you've created a sequence at Illustrate and want to have the components of all steps transparent.

1- Split the model in modelItems: I can imagine tricks to have this done. one of those is: There are buttons with eye icons In the top of 3D view that hides components. it would help you during mappings of complex assemblies by modelItems. 

2- Uncheck the Visible attribute of all modelItems ( before you do this, you can preview your sequence and figure out why this is necessary )

3- Create an Application Parameter called Step and link the output of Current Step attribute from Model to the new parameter' input.

4- At Home.js, write a code like this:

$scope.opp=function() { //opp is the function name
 val=$scope.app.params.step; //val get the value of the parameter STEP
 //every time that this functions was called, the val contains the current step number.
 if(val==1) //If the function was called during the step 1, Change the visible to true and opacity to 0.5 for all model-items of the step 1 
 {
 $scope.view.wdg['modelItem-7']['visible'] = 1;
 $scope.view.wdg['modelItem-8']['visible'] = 1;
 $scope.view.wdg['modelItem-9']['visible'] = 1;
 $scope.view.wdg['modelItem-7']['opacity'] = 0.5;
 $scope.view.wdg['modelItem-9']['opacity'] = 0.5;
 $scope.view.wdg['modelItem-8']['opacity'] = 0.5;
 }
 else if(val==2)
 {
 $scope.view.wdg['modelItem-1']['visible'] = 1;
 $sc
 [...]

5- In my AR experience, I set a button to play the steps of the sequence, I called the function opp() in the click of the button.

Done.

PS: at the Creo illustrate, never set the visibility of a component to start at time=0% of the step. it causes a bug and the component was invisible forever in the Vuforia View if you were following my steps.