I recently attended ITP Camp 2018, a 4 week crash course/playground that I've heard described as "a center for the recently possible," hosted at NYU's Interactive Telecommunications Program. It was a wonderful opportunity to make stuff, learn from people working on the cutting edge of art and engineering, and collaborate with people from diverse disciplines.
I went to a super interesting session on using displacement maps in Blender, a free and open source 3D creation suite. Here's some of my work from that session:
The way that it works is that we basically bring a 2D image into a 3D scene, and then pull out (or extrude) the lighter areas of our 3D object using a displacement map. Here's a screenshot of an intermediary step of the above photo:
Once we extrude the scene, we can point a "camera" in Blender at a specific part and then "take a picture," for lack of a better phrase, to export it back into 2D.
Here's what the "camera" looks like in Blender. It's positioned right on top of the 3D scene and pointing down onto the extrusion. The results can look pretty cool.
Not all images come out well. For every 5 photos I extruded, maybe 1 would come out nicely. Photos of the solar system or the sky at dusk tended to do the trick.