Recently I was asked by a user how to make a solid (uniform = single material) model of a subregion of an anatomical model, e.g. the arm.

Here is what I proposed, with a short animation to illustrate the workflow.

  1. boolean Intersect the skin with a box (first run Mesh Tools -> Mesh Doctor -> Make Manifold, to ensure the boolean intersect is robust)
  2. use the patch selection tool (Mesh Tools -> Select Patches) to select the outer surface of the skin
  3. extract the patch as a triangle mesh
  4. use the Mesh Doctor to close the top/bottom holes
  5. optionally optimize the closed triangle mesh using the Mesh Tools -> Remesh tool

Click on the image below to view the gif animation:
solid_arm_reduce.gif