Point is not controlling curve

When moving a point on a curve in the z-direction, the end of the curve does not move along with the point. How can I get the end of the curve to move?

Once you reference points on a curve (Divide Curve, or Point on Curve, ect) it’s creating new geometry, apart from the curve. You need to take an extra step to rebuild the curve using the points, commonly with Nurbs Curve or Interpolate.


Alternatively you can reference and move the control points themselves, using Control Points and Point Deform, especially useful if you are adjusting Rhino geometry but nurbs points aren’t always as intuitive to control.


Both variations attached.

adj points.gh (11.0 KB)

Thank you. I was wondering how I would make the slope of the curve less steep for people, basically creating a ramp that’s not steep. I need the top of the curve to reach 15ft.

Are you aware of ADA ramp requirements?

The maximum slope of a ramp in new construction shall be 1:12.

A 15ft rise requires a ramp that is 180ft long (15 * 12), which is a half circle with a radius of 57ft.
If you want a smooth transition to horizontal at top and bottom, it has to be slightly longer with a nurbs curve where two points at each end are the same height.

This ramp is 4ft wide, which (come to think of it) is too narrow for such a long ramp.

I forgot about landings. From the same ADA Compliance document:

  • The maximum rise for any run shall be 30 in (760 mm).
  • The landing length shall be a minimum of 60 in (1525 mm) clear.

Given the max rise of 2.5ft for any run, ramps cannot exceed 30ft in run length (2.5ft X 12) between 5ft landings. A 15ft rise divided by 2.5ft = 6 ramps and 5 landings for a total path length of 205ft (6 X 30ft + 5 X 5ft). It’s an interesting geometry puzzle for GH, given a 2D path curve of sufficient length. You could spiral wrap the path around a cylinder of 22ft radius (44ft diameter) for adequate headroom.

P.S. The ramps are blue, the landings are white. Path is 7ft wide.

ramp_2022Oct29a.gh (31.5 KB)

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