Curves with different kinds of corners


#1

Hey, so I’m new to the whole NURBs world and I’m wondering if it’s possible to have a curve with both hard and soft corners. Like, when building a spline in 3DSMax, you can right click the various corner points and make them hard corners, or bezier, or smooth, or whatever.

In my head, I’m thinking the answer is going to be to use a bunch of different curve and line objects and then join them together afterwards … is that right?


#2

The closer you put points together, the more influence they have over the shape of that section of the curve. Also you can edit the ‘weight’ of a point to increase it’s influence. I add additional control points to get more definition. If I’m editing an already created crv, then I call InsertControlPoint to add additional definition.


#3

I think the closest you are going to get in Rhino is using Polyline and changing the mode option. This will at least give you a sharp or filleted corner. But yes, if you a more specific corner (G2 say) mixed with a sharp (G0) corner, making you lines then blending them in a separate step is the way to go.


(Pascal Golay) #4

Hi Warren

You can ‘soften’ a hard corner with RemoveKnot, and create a corner with InsertKink (i.e a fully multiple knot) but this does not really behave the same way as illustrator style and Max, I guess, curves. Joiining, exploding, ExtractSubCrv and Match are the tools you might want to look into. Also HandleCurve, if you like to draw that way…

  • Pascal

#5

also, check out the Fillet command (or FilletCorners if you want to round all corners of a polyline equally)

(and if none of the suggestions are working out for you, it might be best to upload a little drawing showing what you’re after.)


#6

Hey, thanks, yes this is what I’ve been basically doing so far - drawing a polyline and then filleting the corners I want to be rounded off. I guess that’s what I’ll continue with then.

Thanks!