Being able to select portions of a model defining where supports are requested. Rather than adding supports one at a time, or depending on the shaky automatic placement. This could be handled in a number of ways.
1. Selecting individual triangles of the stl to be supported via clicking with the mouse. Perhaps adding limiters by defining stop planes which bisect the selected triangles vertically so supports don't go too far on large triangles.
2. Adding points entities to the stl file in the areas where supports are desired.
3. Adding shapes in the X-Y plane, defining where supports should be created upwards from the build plate (or from the model upwards if they intersect the model vertically).
4. Moving the cursor over the surfaces of the model like a paintbrush highlighting regions that require support (this might be really tough).
