• Adobe After Effects Expressions

  Scale Selected Layers Script

  Posted by Jon Smith on April 18, 2013 at 4:59 pm

  Hey All,

  After Effects comes with a script called “Scale Selected Layers”. It basically creates a null either in the center or upper left of the composition then parents the layers and scales it by a user inputed value. I’m looking for something that just scales the layers without parenting them to a null. I figured I could customize the script to do what I need but after trying a few things I can’t seem to pull it off. Could someone point me in the right direction. Thanks!

  Jon Smith replied 13 years ago 1 Member · 1 Reply
• 1 Reply

• 

  Jon Smith

  April 18, 2013 at 9:44 pm

  I finally got it to work. If anyone is interested here’s the script. It’s a modified version of the “Scale Selected Layers” Script and is handy if you need to scale a bunch of layers by a certain percentage. You can just save the script out as a .jsx file and it should work.

  {

  // Scale Selected Layers Individually.jsx
  // This is a modified script based on :
  // "Scale Selected Layers.jsx" that comes with After Effects
  //
  // This script scales the selected layers within the active comp.
  //
  // First, it prompts the user for a scale_factor.
  // Next, it scales all selected layers, individually

  function ScaleSelectedLayers(thisObj)
  {
  var scriptName = "Scale Selected Layers";

  // This variable stores the scale_factor.
  var scale_factor = 1.0;

  //
  // This function is called when the user enters text for the scale.
  //
  function on_textInput_changed()
  {
  // Set the scale_factor based on the text.
  var value = this.text;
  if (isNaN(value)) {
  alert(value + " is not a number. Please enter a number.", scriptName);
  } else {
  scale_factor = value;
  }
  }

  function onScaleClick()
  {
  var activeItem = app.project.activeItem;
  if ((activeItem == null) || !(activeItem instanceof CompItem)) {
  alert("Please select or open a composition first.", scriptName);
  } else {
  var selectedLayers = activeItem.selectedLayers;
  if (activeItem.selectedLayers.length == 0) {
  alert("Please select at least one layer in the active comp first.", scriptName);
  } else {
  // Validate the input field, in case the user didn't defocus it first (which often can be the case).
  this.parent.parent.optsRow.text_input.notify("onChange");

  var activeComp = activeItem;

  // By bracketing the operations with begin/end undo group, we can
  // undo the whole script with one undo operation.
  app.beginUndoGroup(scriptName);

  // Scales the layers.
  var myLayers = activeItem.selectedLayers;
  for (i=0; i <= myLayers.length-1; i++){

  currentLayer = myLayers[i];

  var layerScale = currentLayer.scale.value;
  layerScale[0] = layerScale[0] * scale_factor;
  layerScale[1] = layerScale[1] * scale_factor;
  currentLayer.scale.setValue(layerScale);

  }

  app.endUndoGroup();

  // Reset scale_factor to 1.0 for next use.
  scale_factor = 1.0;
  this.parent.parent.optsRow.text_input.text = "1.0";
  }
  }
  }

  //
  // This function puts up a modal dialog asking for a scale_factor.
  // Once the user enters a value, the dialog closes, and the script scales the comp.
  //
  function BuildAndShowUI(thisObj)
  {
  // Create and show a floating palette.
  var my_palette = (thisObj instanceof Panel) ? thisObj : new Window("palette", scriptName, undefined, {resizeable:true});
  if (my_palette != null)
  {
  var res =
  "group {
  orientation:'column', alignment:['fill','top'], alignChildren:['left','top'], spacing:5, margins:[0,0,0,0],
  optsRow: Group {
  orientation:'column', alignment:['fill','top'],
  text_input: EditText { text:'1.0', alignment:['center','top'], preferredSize:[200,20] },
  },
  cmds: Group {
  alignment:['fill','top'],
  okButton: Button { text:'Scale', alignment:['fill','center'] },
  },
  }";

  my_palette.margins = [10,10,10,10];
  my_palette.grp = my_palette.add(res);

  // Workaround to ensure the edittext text color is black, even at darker UI brightness levels.
  var winGfx = my_palette.graphics;
  var darkColorBrush = winGfx.newPen(winGfx.BrushType.SOLID_COLOR, [0,0,0], 1);
  my_palette.grp.optsRow.text_input.graphics.foregroundColor = darkColorBrush;

  // Set the callback. When the user enters text, this will be called.
  my_palette.grp.optsRow.text_input.onChange = on_textInput_changed;

  my_palette.grp.cmds.okButton.onClick = onScaleClick;

  my_palette.onResizing = my_palette.onResize = function () {this.layout.resize();}
  }

  return my_palette;
  }

  //
  // The main script.
  //
  if (parseFloat(app.version) < 8) {
  alert("This script requires After Effects CS3 or later.", scriptName);
  return;
  }

  var my_palette = BuildAndShowUI(thisObj);
  if (my_palette != null) {
  if (my_palette instanceof Window) {
  my_palette.center();
  my_palette.show();
  } else {
  my_palette.layout.layout(true);
  my_palette.layout.resize();
  }
  } else {
  alert("Could not open the user interface.", scriptName);
  }
  }

  ScaleSelectedLayers(this);
}

Reply to this Discussion! Login or Sign Up