Reference Point for Transform Commands in Photoshop

Reference Point for Transform Commands in Photoshop

Transform commands are among the most used in Photoshop. There is a good reason for that. Usually, we are starting with importing and drawing/painting elements in our layered composition to end up with the desired final result which most of the time needs additional work including transformations. When it comes to transformations, most of the users that I know are actually omitting or ignoring references point which is by default set to center. In this post, I want to draw your attention to the Reference point. I will explain a you importance and how you can use it in your everyday workflow while creating new content, re-purposing content or even when automating tasks using actions and variables. The Reference point that we will discuss in this tutorial is similar to Reference point for Alignment option in the Variables dialog, but not and exactly the same.

Why is Reference point so important

First of all, transformations that you are applying in Photoshop from Edit > Free Transform and Edit > Transform > choose an option, will always use a reference point around which will be applied transformation. Even Transform Again and Transform Again With Duplicate (Step and Repeat or Array Tool) will remember reference point and use it. I already have used reference point as a key in some of my recent tutorials about Transform commands. I haven't highlighted it or to give you more explanations and how this feature can be used for other common tasks with transformation commands. You can check out Lesser Known Transformation Options in Photoshop CC and How to Build Complex Shapes in Photoshop CC. More examples you can see in my actions Single Image Collages (currently actions in this package work with Photoshop CS6, do not use them with the later version).

The Reference point is determining spot on layer bounds (bounding box) or in the document (outside the item) around which will be performed transformation like rotation, scaling or flipping. Three different final results you will get when rotating around Reference point set to center of layer, bottom right corner of the layer bounds or the center of the document.
Same object rotated with the same rotation angle but different Reference point

Notice that I am referring above to layer bounds or bounding box. This is because nothing can be irregular shape or circle; every image or layer must be rectangular or square. When you look at circle on your screen you are looking at the shape that is surrounded with transparent pixels, actual image or layer is always rectangular or square.

How to manually move Reference point anywhere in the document
To move the Reference point anywhere in the document do the following:

  1. Select layer/layer group in the Layers panel.
  2. Press Ctrl/Cmd + T to enter Free Transform mode (Edit > Free Transform)
  3. Navigate the mouse over the circle (Reference point) inside bounding box and it will turn into Move Tool icon.
  4. Click and drag circle which is actually Reference point anywhere you want.
Move the Reference point anywhere in the document in Photoshop

The very best way to present importance and what can be done using Reference point is to give you some practical examples. Let's see the reference point in action.

Practical examples of using Reference point

I will list few examples starting with most common situations where Reference point can be used.

Scaling
The most common transformation task is certainly scaling of an object/layer/layer group. Let's say you are fine with the position of an object or shape relative to the top and left side of your document, but you want to scale it down so longer side is 350px. Do the following:

  1. Select layer/layer group in the Layers panel with the object you want to scale.
  2. Press Ctrl/Cmd + T.
  3. Change Reference point to Top Left
  4. Right click inside text field next to W in the Options bar and change measurement unit to Pixels
  5. Optionally click on the chain icon to activate Constrain proportions.
  6. Highlight all inside text field next to W in the Options bar and retype with 350px.
  7. Press Enter/Return twice to confirm.
Scale object with fixed top left position

You have scaled down the object to desired dimensions while top left corner hasn't changed its position.

Moving and positioning objects
If you want to ensure that top left of your layer or layer group in composition is 200px from the left side of the document and 250px from the top you can use Free Transform and Reference point for that task. Do the following:

  1. Select layer/layer group in the Layers panel.
  2. Press Ctrl/Cmd + T.
  3. Change Reference point to Top Left.
  4. Highlight content in the text fields next to X and Y in the options bar and retype it with 200px in the text field for X position and 250px in the text field for the Y position.
  5. Press Enter/Return twice to confirm.
Set position with top left reference point

Now what if you want to move objects for 75 pixels pros the top of the document. Do the following:

  1. Select layer/layer group in the Layers panel.
  2. Press Ctrl/Cmd + T.
  3. Click on the triangle (Use relative positioning for the reference point) in between X: and Y: Type: -75 pixels in the text field next to Y: that refers to distance from the top of the document.
  4. Press Enter/Return twice to confirm.
Move object pros top using reference point


Mirror effect
The Reference point is useful and when creating mirror or reflection effect. Steps to reproduce mirror effect:

  1. I will assume that you have only one: Background layer in the document. Convert it to a normal layer before duplicating.
  2. Duplicate layer.
  3. Go to Image > Canvas Size and expand Width to the right (click on the left arrow in the Anchor section). Ensure that Relative is unchecked and set measurement unit to: Percent. Type 200 in the text field next to Width. Click OK to confirm and exit.
  4. Ensure that you have duplicated layer selected in the Layers panel and press Ctrl/Cmd + T to enter Free Transform mode.
  5. Move Reference point to the right edge using mouse or simply click on the middle right (any on the right side will work) square on the Reference point location in the Options bar.
  6. Right mouse click inside the canvas and choose: Flip Horizontal
  7. Confirm on Enter/Return and you are done.
Mirror effect using Reference point and Flip horizontal

Actions to create a mirror effect
I have recorded actions that you can download from here. Actions can be used in Photoshop and Photoshop Elements to create a mirror effect. There are 4 actions or options:

  • Mirror Left - will expand canvas to the left and mirror duplicated layer.
  • Mirror Right - will expand canvas to the right and mirror duplicated layer.
  • Mirror Top - will expand canvas to the top and mirror duplicated layer.
  • Mirror Bottom - will expand canvas to the bottom and mirror duplicated layer.

Note: actions will open a dialog to navigate to the image on your drive. If you have opened an image, then simply expand action and click on Toggle item on/off on the left side of the step: Open.
Toggle step in Photoshop action on/off

You can use the same actions to continue mirroring multiple times, just uncheck checkmark on the left side of Open step as explained previously.
Continue mirroring after toggling Open step off

When you can and when you cannot use Transformation options and Reference point

You can transform pretty much everything that you have in the Layers, Channels and Paths panels. You can transform saved Alpha channel, Path, layer group, Smart Object, Type or Shape layer or even Layer and Vector masks. What you cannot transform are layers with locked position, Background and Adjustment layers which do not have actual content.

You can also Transform Selection or to Transform pixels inside the selection. Those are two different commands: with the selection active, Edit > Free Transform or Transform > option will allow you to transform pixels inside the selection while Select > Transform Selection will allow you to transform selection only without to affect pixels inside the selection.

Product used in this tutorial:
Adobe Photoshop CC 2014

Reference:
Photoshop Help / Transforming objects

Comments

  1. CC2015: "Transform Again" does NOT respect the previously chosen reference point, it always reverts to the center. Previous versions did respect it, IIRC.

    ReplyDelete

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