A great enhancement to Inventor (IMHO) would be an extrude "From" option. This option would give the ability to extrude by "Distance" but from another surface other than the sketch plane.
When modelling top down, one often has cross-section sketches with components in the cross-section that are not symmetrical about the sketch plane. You can use assymetric distance extrusion in this case, but now you have to figure out how to divide your length formula into two parts so that the right proportion falls on each side whenever the model changes to a different size.
An extrude "From" option would work much better. Using this option you could pick the surface on which you wanted to start the extrusion and enter a distance formula. The part is now fully parametric. This option would be sort of like the opposite of the extrude "To" option except you could supply a distance for the part length allowing the part to begin at the "From" plane and stop short of the sketch plane or continue on through it an assymetrical amount.. It would also be like the "Between" option except that you would supply a distance rather than a second surface when the second surface is not readily available.
Would anyone else find this enhancement useful? Perhaps something like this already exists and I am just not aware of how to do it.
Steve
