VB control points for surface/brep

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Permalink Reply by Jacquelyne Cooper on February 26, 2012 at 6:38pm

not sure if you have already tried this but I would try to do it by attatching a slider to the center control point and using it to control its movement  or maybe create a boundry curve and offet it to just inside the edge curves and link that to the center points.

Permalink Reply by Sven Nevlida on February 26, 2012 at 7:30pm

I wanna do it by using VB script component... so I'm looking for the right command..

Permalink Reply by Andy VanMater on February 27, 2012 at 1:13pm

Alright, I've gotten something together that solves the problem but I don't like the way that I made sure it was still "in" the surface. Hopefully this will get you on your way.

 

 

'Turn your input surface into a nurbs surface

Dim s As NurbsSurface = x.Duplicate

'Get the middle control point, assign its location to a point3d for transforming purposes

Dim cpList As rhino.Geometry.Collections.NurbsSurfacePointList = s.points

Dim cp As controlpoint = cpList.GetControlPoint(1, 1)

Dim pt As point3d = cp.Location

'Turn the surface into a brep (to get the edges)

Dim be As rhino.Geometry.Collections.BrepEdgeList = s.ToBrep.edges

Dim el As New List(Of Curve)

For i As int32 = 0 To be.count - 1
el.add(be(i).ToNurbsCurve)
Next
Dim bnd() As curve = curve.JoinCurves(el)

'move the point according to the sliders

pt.Transform(transform.Translation(New vector3d (sliderX, SliderY, SliderZ)))

'check if the moved point is in the boundary (projected to the XY plane in this case)

If bnd(0).Contains(pt, plane.WorldXY) = PointContainment.Inside Then

'if yes then make the controlpoint = the point3d

cp = pt
cpList.SetControlPoint(1, 1, cp)
Else

'if not then do nothing to the point but let the user know

print("the control point is outside the boundary of the surface")
End If

'output your modified surface

output = s