Questions about Control Points and Clarifying the Assignment’s Single Revolve Constraint

In an email, Laura asked:
“…in the process of revolving my curves about a million Control points were added to the original revolve curves for no apparent reason….I’ve been trying the fix the problem for ages now but nothing’s working. “

Most likely the “new” points appeared after joining separate curves together into a “polycurve”. It is necessary for Rhino to add control points in many situations when curves are joined We will talk about why soon). If these polycurves are exploded, you will find that the individual curves should return the original control point count. Also, when curves are offset, the offset curve will be more complex (have more points) in order to satisfy the conditions of the offset (dimension, tolerance). That is why the assignment requires that the curves be exploded before taking the screen shot. It’s OK if offset curves are complex, we can decipher what has happened in that situation.

“…by one revolve do you mean one revolve axis or one revolve curve?”

When we say a “single revolve” it just means that one can only use a “full circle” (360 degree) revolve to build each glass. The curve used to revolve the glasses can be a single, simple curve, but most likely it will need to comprised of several curves joined into a polycurve, as is demonstrated in the video. It is permissible to have two totally separate curves, if the intention was to make a bubble within the base of the glass, for example. But this curve would need to use the same axis as the other curves. In that case, both sets of curves could still be formed at once. If the design somehow incorporated two revolves, using different axis, then that would go against the constraints for this project.


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