Way to Project curves onto surface and maintain low or same point count?

Hey guys, I’ve found that when I project curves onto a surface, the point count goes way up on the projected curve, compared to the original 2D curve I created. I realize that it ends up a more complex curve because it’s 3D, but it would be great if I could keep that point count low, or even the same as the original.

Reason being that I’ve found it useful to trim away from the projected curve and then build a curve to near it, then Sweep2 them, to build off the trimmed surface. Problem though is that the new curve I made is nice and clean and has a low point count, and this does not match the high point count of the projected curve.

I’m aware of the rebuild command, but as far as I know, reducing the point count with this method causes the curve to no longer match the edge of the surface, which I need in order for the Sweep2 to line up with the edge.


The high point count is needed so the curve fits the surface within the current file tolerance.

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pull cuve will do just that,

BUT… it may not be precise enough to follow your surface precisely if there is a lot of curvature.

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Oh nice, I’ll give the pull curve a try.

Hi Joel - both Project and Pull have a ‘Loose’ option that will maintain the curve structure, but the result is not guaranteed to be within tolerance of the target if Loose=Yes. Without Loose=Yes, both Pull and Project will make a fit curve that is as complex as needed to be within tolerance of the target.

Pull and Project also work directly on selected control points.


One way I have dealt with this as an alternative to pull curve, is to create an extrusion of the original curve, then use the intersect command with the object, then delete the extrusion.

One other way is to explode the curve, and rebuild each section with enough points to keep the deviation to something within tolerance, the rejoin everything. For example, your arcs and straight lines have way more points than needed.

If the cross section of the sweep is linear, _Loft can instead be used to produce surfaces with only the overlapping structures of the input curves.