Well, I'm not sure how exactly you want it to look, or where you're stuck, so here's a short outline how to do it using the mixed materials method. 1.click on the material(top right corner) to get into the (advanced)material editor. 2.Click on the material icon and assign one of the materials. (stones colorful in my example) 3.Check that 'displacement mapping' is ticked (and chose the depth and scale) 4.Chose the type as 'mixed material' 5.click the new material and upload the material you want for bumps only (grass) 6.Right click on the 'distribution of materials 1 and 2' to get into the function editor 7.Add texture map node. Click the little arrow under the map on the left side and navigate to the place where tour bitmap is and select it. If you dont have a bitmap you'll have to make one in photoshop or a similar application. (Like in Cherryman's example - you'll need a bit map defining where the blood vessels are. I'm attaching a new screen capture (sorry, didnt save the one in the previous post) with arrows Highlighting   the important points.

I Could send you the vue file for this if you PM me.
Post if you have any specific questions or if you get stuck...

"I paint that which comes from the imagination or from dreams, or from an unconscious drive. I photograph the things that I do not wish to paint, the things which already have an existence."
Man Ray, modernist painter
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