For all of you crazed 3D-modeling, equation-using junkies out there, you may be really, really excited to know that your equations will update in real-time when using Instant3D in SolidWorks 2008.
Jeff, from ExtensibleCAD, shows this happening when using logical (if-then) equations to drive features. See video below. The equation is set up to change the number of spokes when the diameter changes. If the diameter is X then number of spokes is Y and it’s all done as you drag your mouse around.
One caveat to this is that the model and the Instant3D updated can get really slow and clunky the more complicated the equations and changes are. If your dimensions are driven by other features you’ll also not be able to adjust those.