I’ve been creating tileable normal maps using zBrush by exporting zDocs with the normal material applied, it turns out I also need height/displacement maps from these docs. Does anyone know how to get them from a zDoc?
Pressing the GrabDoc button towards the bottom of the Alpha palette will copy the ZDepth into a new 16 bit alpha. Export through the Alpha palette.
You can also use the MRGBZ grabber tool, wich creates a texture, and a height map form the document 
Hey thanks guys! Now I can work with things that go bump in the night out of the normal.