Adobe AfterEffects script (JSX):Z_scale

Z_scale_v20150716.jsx

/*
Adobe AfterEffects Script (JSX)
	Z_scale
		v20150716
*/

////////////////////////////////variable declaration////////////////////////////////
var thisComp= app.project.activeItem;
var selectedLayers= new Array();
var thisLayer = null;
var distance,newScale,cam,CamP,CamZ;
var thisW,thisH,newCamera;

////////////////////////////////body////////////////////////////////

app.beginUndoGroup("FitToComp_offsetZ");

if(thisComp instanceof CompItem){
    selectedLayers = thisComp.selectedLayers;
    if(selectedLayers.length > 0){
        
        cam = thisComp.activeCamera;
        if (cam == null){
            createCam();
            cam = thisComp.activeCamera;
        };
    
        CamP = cam.position.value[2];
        CamZ = cam.Zoom.value;
        
        for(i=0; i < selectedLayers.length; i++){
            thisLayer = selectedLayers[i];
            if (thisLayer.threeDLayer){
                adjustScale(thisLayer,CamP,CamZ);
            };
        };
    } else {
        alert('unselected layer'); 
    };
} else {
    alert('unselected compositon');
};

app.endUndoGroup();


////////////////////////////////functions////////////////////////////////
function adjustScale(Lay,ValP,ValZ){
    distance = Lay.Position.value[2] - ValP; 
    newScale = (distance / ValZ) * 100;
    Lay.scale.setValue([newScale,newScale,newScale]);
};
function createCam()
{
    app.beginUndoGroup("Create Camera");
    
    thisW = thisComp.width /2 ;
    thisH = thisComp.height /2 ;
    newCamera = thisComp.layers.addCamera("camera", [thisW,thisH]);
    newCamera.Position.setValue([thisW,thisH,newCamera.Position.value[2]]);
    
    app.endUndoGroup();
};