Liquify

The Liquify filter is designed to let you carry out freeform pixel distortions. When you choose Filter ➯ Liquify (or use the CSx [Mac], LSx [PC] keyboard shortcut), you are presented with what is known as a modal dialog, which basically means you are working in a self-contained dialog with its own set of tools and keyboard shortcuts, etc. The Liquify filter therefore operates like a separate program within Photoshop. To use Liquify efficiently, I suggest you first make a marquee selection of the area you wish to manipulate before you select the filter, and once the dialog has opened use the C0 (Mac), L0 (PC) keyboard shortcut to enlarge the Liquify filter dialog to fit the screen. Basically, you can use the Liquify tools to manipulate the image and when you are happy with your liquify work, click the OK button or hit E or R. Photoshop then calculates and applies the liquify adjustment to the selected image area. The Liquify tools are all explained in the column on the left and Figure 7.17 provides a visual guide to what they can do. One of the main things to point out here is that Liquify is optimized to make use of the GPU (Graphics Processing Unit) and provide good overall responsiveness. As a consequence of this the turbulence and mirror tools were removed when Photoshop CS6 came out. This is because they couldn’t be enabled to work with the GPU, but it’s not such a great loss as people weren’t using these particular tools a lot anyway. The Liquify filter opens in a basic mode of operation (Figure 7.18), where initially only the forward warp, reconstruct, pucker, bloat, push left, hand and zoom tools appear in the tools section. You also have just a simplified set of tool options and you’ll need to check the Advanced mode box if you want to access the full list of tools and other Liquify options (Figure 7.19). The easiest tool to get to grips with is the forward warp tool, which allows you to simply click and drag to push the pixels in the direction you want them to go in. However, I also like working with the push left tool, because it lets you carry out some quite bold warp adjustments. Note that when you drag with the push left tool it shifts the pixels 90° to the left of the direction you are dragging in and when you A drag with the tool, it shifts the pixels 90° to the right. The key to working successfully with the Liquify filter is to use gradual brush movements and build up the distortion in stages.