Hi, I am fairly new to Rhino after years of using Sketchup so I’m also fairly new to the correct terminology/term for the curve world. So I’m working to create a handrailing for this irregular staircase design that has curve fillets on some of its corner. The handrailing should have the controlled height of 1200 mm. So my method is to make the 1200 mm height points on each staircase step’s end & on each curve starting point, make lines connected from each point’s ends, and use BlendCrv on each gap with curvature continuity for 1 and 2 ends because the railing will be installed on the side of the railing following the outer boundary shape of the staircase (so I assume that curvature continuity will maintain the projection of the curve shape’s X & Y position and only adjust its Z position?), so it would not have any gap with the staircase edges.
The problem is that there is a “sharp” corner in which I know it would be a painful job to be constructed in real life (I think this is because the combination of the need to keep its X&Y position with the staircase original shape, and the maintain of 1200 mm and the turn itself):
It’s more apparent after I sweep2 the path with the desired railing profile:
Desired result (while maintaining its X & Y Position, so I think I can’t use BlendCrv + Tangent continuity to solve this because it will move the X & Y position):
I know that in my mind, I can make this corner better if I break the rule of maintaining the 1200 mm just on the first extension (red), so that it can transition smoothly (and mirror it to the other side of the staircase):
My problem is, I don’t know the method to find how much should I lower the first red curve (before it meets the sharp corner) so that it will blend with curvature continuity better with the curve after the sharp corner?:
I can solve this IF that part is not a curved turn. If it’s a straight path, I can just extend the 2nd end, and move down the 1st end until it touches/intersects. But since im dealing with a curved turn, how can I do this? I hope it makes sense, as I’m having a bit of a hard time explaining it with the right term as well. Any help would be very much appreciate it. Thanks!
Staircase Exercise.3dm (7.8 MB)