How to get the Point3D where 3 planes intersect with vb?

Hi, take a look at the attached image if you find the time.

I would like to calculate the point3d (the red dot) where 3 planes intersect with vb.

The things I know are the center points of the planes (blue dots) and the normalvector at those points (orange lines).

I was wondering if there are functions in vbscript that make this calculation easier.

By the way, the locations of the center points of the planes are irregular and do not have the same distance between them.

Thanks for any help!
Fernando

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intersection_planes.jpg, 62 KB

Replies to This Discussion

Permalink Reply by David Rutten on May 9, 2012 at 9:34am

I'll assume you mean VB.NET, not VBScript, as VBScript cannot be used inside Grasshopper.

There's a Shared method inside the Rhino.Geometry.Intersect.Intersection class called PlanePlanePlane() which finds the point where the three planes intersect:

Dim pt As Point3d

If (Rhino.Geometry.Intersect.Intersection.PlanePlanePlane(A, B, C, pt)) Then

'Planes intersect at pt, if this function returns false, the planes are either invalid or parallel

End If

You'll first need to create your A, B and C planes from original point and normal vector using the appropriate constructor.

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by Fernando Conti on May 9, 2012 at 11:06am