SurfaceAreaMoments

Calculates the area moments of inertia of a surface or polysurface object. For more information, see the Rhino help file for "Mass Properties Calculation Details."

Syntax

Rhino.SurfaceAreaMoments (strObject [, intFaceIndex])

Parameters

strObject	Required. String. The object's identifier.
intFaceIndex	Optional. Number. If the object is a polysurface, then the index of the face to query.

Returns

Array

An array of area moments of inertia information if successful. The array will contain the following information:

Element	Type	Description
0	Array (X,Y,Z)	First Moments.
1	Array (X,Y,Z)	The absolute (+/-) error bound for the First Moments.
2	Array (X,Y,Z)	Second Moments.
3	Array (X,Y,Z)	The absolute (+/-) error bound for the Second Moments.
4	Array (X,Y,Z)	Product Moments.
5	Array (X,Y,Z)	The absolute (+/-) error bound for the Product Moments.
6	Array (X,Y,Z)	Area Moments of Inertia about the World Coordinate Axes.
7	Array (X,Y,Z)	The absolute (+/-) error bound for the Area Moments of Inertia about World Coordinate Axes.
8	Array (X,Y,Z)	Area Radii of Gyration about the World Coordinate Axes.
9	Array (X,Y,Z)	The absolute (+/-) error bound for the Area Radii of Gyration about World Coordinate Axes.
10	Array (X,Y,Z)	Area Moments of Inertia about the Centroid Coordinate Axes.
11	Array (X,Y,Z)	The absolute (+/-) error bound for the Area Moments of Inertia about the Centroid Coordinate Axes.
12	Array (X,Y,Z)	Area Radii of Gyration about the Centroid Coordinate Axes.
13	Array (X,Y,Z)	The absolute (+/-) error bound for the Area Radii of Gyration about the Centroid Coordinate Axes.
14	Array (X,Y,Z)	Area Principal Moments of Inertia about Centroid and Principal Axes
15	Array (X,Y,Z)	The X direction of the Area Principal Moments of Inertia about Centroid and Principal Axes.
16	Array (X,Y,Z)	The Y direction of the Area Principal Moments of Inertia about Centroid and Principal Axes.
17	Array (X,Y,Z)	The Z direction of the Area Principal Moments of Inertia about Centroid and Principal Axes.

Null

If not successful, or on error.

Example

Const rhObjectSurface = 8

Dim strObject, arrMP

strObject = Rhino.GetObject("Select a surface", rhObjectSurface)

If Not IsNull(strObject) Then

arrMP = Rhino.SurfaceAreaMoments(strObject)

If IsArray(arrMP) Then

Rhino.Print "Area Moments of Inertia about the World Coordinate Axes: " & Rhino.Pt2Str(arrMP(6), 4)

End If

Also See

SurfaceArea

SurfaceAreaCentroid