Remove extra geometry from objects Is there a tool or an easier way to remove unneeded geometry from objects? Mostly when using a "Displace" modifier, on many places there are flat surfaces where there is extra geometry on the mesh, that you would like them to be removed. At first I thought of the "Decimate" modifier, but is there a way to do it more evenly. By preserving the edge/face flow and such. Is there some feature for something like that in Blender?


From this





To this





Or to this (if I want the geometry to be to the very limits and worrying only about the shape)
Manual with good topology

To get the topology in your second image. Select the loops you want to delete with Alt RMB , or in Wireframe mode use border select (B). Then press Delete and choose Edge Loops.  

Manual with N-gons

To delete all edges and vertices on a face and just be left with a large N-gon. Select all the faces on a plane (example everything on the top); then press Delete and choose Limited Dissolve.

Modifiers

If you are less picky about topology, and want a more automatic solution Then use a Decimate modifier. For examples like your's set the Decimate modifier to Planar, then adjust the angle limit to suit your needs.