As you might have guessed from the name, Meshmix was the original function of the app. It allows you to quickly "mash-up" surfaces by drag-and-dropping meshes onto existing surfaces. To use this tool, start by clicking on the Meshmix button. This will reveal a default set of "parts" that you can drag onto your model. They are organized by category.
There are two main modes for the Meshmix tool: Drag and Drop and Drop Solid. The mode is determined by which part is chosen from the set of parts.
Drag and Drop
With this mode, you can drag an open part (i.e. a part with a boundary) onto the mesh. Move the dropped part over the surface using the UI widget. The new part actually inserts itself into the existing surface. When you click Accept, the result is one continuous surface which includes the original surface and the new part.
Type (COILS or Rotation Invariant Coordinates) are different approaches to deforming the dropped part to fit the target surface. See the papers in the Further reading section below for more details.
Optimize attempts to preserve the shape of the original part, but may cause a less smooth transition region between the target and dropped shapes.
Flip will place a mirrored version of the object.
In this mode, you can drop a closed (solid) object over the surface. It will not attempt to insert the mesh while you are interacting with it. When you click Accept, it will attempt to merge the surfaces using the Composition Mode you've chosen in the drop down.
Append To Mesh: Does not attempt to merge the objects into a single shell. Instead creates an object with two disjoint shells.
Create New Object: Adds the solid to the scene as a new object.
Boolean Union: Creates a single surface by performing a Union operation on the existing target shell and the solid being dropped. (See the manual entry for the Boolean tool for more info.)
Boolean Subtract: Produces the surface given by "cutting out" the solid part from the target surface. (See the manual entry for the Boolean tool for more info.)
The Drag and Drop tool was originally an implementation of some of the ideas from the following tech reports. If you'd like to know more of the mathematical details, the reports are available here:
- Drag-and-Drop Surface Composition (2009). Ryan Schmidt, Karan Singh. Technical Report CSRG-604, Department of Computer Science, University of Toronto. [PDF]
- Drag, Drop, and Clone: An Interactive Interface for Surface Composition (2010). Ryan Schmidt, Karan Singh. Technical Report CSRG-611, Department of Computer Science, University of Toronto. [PDF]