#2 Parameterized variable constraints

[Jess Wright]

Evaluate the options.

Case:
Parameterized variables have constraints.

Options:
1. Should the min and max of the slider be initially set to those constraints? If the range between constraints is very large, might be cumbersome (otoh, may still be more relevant initial values than arbitrarily choosing them the same for all cases, i.e. always -5, 5)
2. Should the sliders be constrained so as not to even allow values that are not in the range? i.e. values that would result in a null rendering? The transform is legal, it just has an empty result. It's kinda irritating to move the slider and have the polyhedron disappear because you scrolled too far.

1 is a softer version of 2 and alleviates the annoyance of scrolling past the edge of the polyhedron or having to manually set the min/max for the scrollbars immediately after entering a polyhedron while still allowing the user to change the min/max if, for some reason, they really want to scroll past the edge and see an empty view.