I already blogged about this, but I saw that some items could use some more explanation. Please read “Getting the displacement you need” first for the basic idea.

In short the principle is:

• you have a reference map, say A
• you apply a distortion effect to the reference map created a distorted version of A say A’
• you calculate the displacement map that could transform A into A’ by calculating the difference in pixel value between A and A’

Some important points before we start:

Use a lossless image format (eg bmp). If you use lossy compression anywhere in the pipeline, you are throwing information away. This missing information results in artifacts in the displacement map. So, save all images as BMP for example. Import them into flash and set the properties to lossless.

We will now describe some steps in my previous post in some more detail. (more…)