Basically I draw alpha channels in GIMP. This gives you the ability to use all the standard raster tools. Like pen tool, airbrush, gradient, layers etc. When you draw in black and white grayscale on individual layers then set the layer modes to darken only they will blend in together according to darkness. One good thing about doing relief like this is that you are stuck within the 256 color range so the stuff can only be so deep on a 2D plane. Let me know what kind of stuff you create.
If you set up gimp as your zaplink then you must export the file as psd before entering back to zbrush.
Here’s a simple video of how it works:
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Here’s a video of some designs:
<iframe width=“560” height=“315” src=“https://www.youtube.com/embed/OZqmxaDsLjw” frameborder=“0” allowfullscreen=""></iframe>