In Meshmixer there is a tool called "Attract" where you designate a target mesh and an object mesh. With that tool, the object gets attracted to the target. This is a way to snap one mesh (very irregular and deformed) to another irregular and deformed mesh. Is there anything like this in Blender?
I need to clarify this even further: suppose you have a real object with a hole and want to create a piece, using 3D printing, to fill the hole and fix the object. For example: a plastic bottle with a hole in the lateral surface. Then you scan it to get a mesh into an .stl file. The "hole" in the mesh can be very irregular and the border edges are rounded, so the mesh does not behave as fine as in the built in meshes of Blender. So, I think in designing a piece that have "more or less" the form and shape of the hole and try to accommodate (deform) it to the form and shape of the hole in order to fit "exactly". The problem is that here you work with a mesh comming from an .stl file and the object can be very iregular, so is its hole also. I believe that this can be done in Blender, but... how? How do you create a mesh that fits the missing piece?
Here's a video of the tool in action: https://www.youtube.com/watch?v=oxTBTMJvUxw