#85 Alt-Zoom Problems with Meshes

[metaphorz]

I posted this issue a while ago, but didn't phrase the
problem correctly. The problem can be reproduced
as follows, at least within modrex

(1) Create a mesh from a default-sized
cube prim. Try "Jack.mesh" for example.

(2) Target an Alt-Zoom at the "invisible" cube
prim that serves as the root of the mesh (or
at least its reference). For Jack, the cube
will located just below the knees extended down
to the feet.

(3) Note that Alt-Zoom mouse motions seem natural,
with small movements of the mouse, the camera
moves smoothly.

(4) Now try to target the upper body, away from
the invisible cube that was used to create the
mesh. Note that the mouse is extemely sensitive
to minor movements and the slightest mouse movement
while doing Alt-Zoom makes the camera fly off.

This problem was not observed for primitives, only
for meshes.