Creating the center point of a rectangular plane in python

Scripting
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1

Hello everyone,

I am running through an issue using RhinoScriptSyntax. I want to create planes along a curve and I want them to be centered on the curve. I am using the rs.PlaneFromNormal() function and it creates a plane with the origin being the point on the curve. The planes aren’t parallel to any global C-plane or global axis.
Now I want the plane to be centered on that point. For that I can use both rs.MovePlane() or rs.Move Object() but I need in both cases (new origin or translation vector) I need the center of the plane.
I didn’t find how to create the contour of my plane to use rs.CurveAreaCentroid(). And neither how to create a diagonal to get its center point.

If any of you has already faced the problem, I’d be very glad to hear how you solved it.

Thanks,
Léon

2

I’m a bit confused. Can you supply some code and screenshots?

These quotes seem contradictory. The plane is already centred on the curve point already.

3

I’m sorry for not being clear. Here is a code sample to explain what I’m trying to do along with some screenshots of the current state and the expected result.
Here is the code sample:
`import rhinoscriptsyntax as rs

crv = rs.GetObject(“Pick the curve”, 4)
orig_point = rs.GetObject(“Pick the origin”, 1)

pt_param = rs.CurveClosestPoint(crv, orig_point)
tan_vec = rs.CurveTangent(crv, pt_param)
geom_plane = rs.PlaneFromNormal(orig_point, tan_vec)
psurface = rs.AddPlaneSurface(geom_plane, 40.0, 40.0)`

Current state:

current_state
current_state533×676 58.9 KB

Desired result:

Desired_result
Desired_result491×745 46.8 KB

In order to do that, I need to translate the plane and thus I need the coordinates of the center point of the plane. With that I can create a translation vector and move the plane accordingly.

Is it clearer ?

4

OK, you were referring to a surface the whole time. “Plane” is usually understood here as a geometrical construct defined by an origin, and a x- and y-axis, not a planar surface. :wink:

This should do the trick:

import rhinoscriptsyntax as rs

crv = rs.GetObject("Pick the curve", 4)
orig_point = rs.GetObject("Pick the origin", 1)

pt_param = rs.CurveClosestPoint(crv, orig_point)
tan_vec = rs.CurveTangent(crv, pt_param)
geom_plane = rs.PlaneFromNormal(orig_point, tan_vec)
psurface = rs.AddPlaneSurface(geom_plane, 40.0, 40.0)

center = rs.SurfaceAreaCentroid(psurface)[0]  # surface center
vec = rs.VectorSubtract(orig_point, center)  # translation vector
rs.MoveObject(psurface, vec)  # move surface
5

Thank you very much ! I did not find any evidence of the SurfaceAreaCentroid method, just of the CurveAreaCentroid method. That’s why I was lost !
Thanks so much !