Principal axes bounding box

Compute the principal axes bounding box of a point cloud.

Access methods

8 Toolbar: PA_BB_32x32 

8 Menu: ComputationalCAD † Principal axes bounding box

7 Command entry: CC:HULL:PABB


Select points:
Select at least four non-coplanar points for which to compute the principal axes bounding box.


The principal axes bounding box is the bounding box along the principal axes of inertia of the 3d convex hull of the point cloud. Along these axes, the minimum extents of the convex hull define the extents of the bounding box.

In a general case, the principal axes bounding box is a very tight bounding box of a point cloud. However, tighter bounding boxes may exist. The quality (tightness) of the principal axes bounding box is the better the more distinct the values of the mass moment of inertia are. In contrast, the principal axes bounding box may be very poor for example for a cube, which has the same mass moment of inertia about its centre for any axis.

hint   Use Generate points on primitives and Generate points on solids to generate input data.




Figure 47: Principal axes bounding box and convex hull of 195 points

Command line prompt:

Principal axes bounding box properties:


Width              : 695.3335

Length             : 2144.3264

Height             : 730.5104

Volume             : 1089207088.4633

Center             : (2619.7359, 1095.8920, 0.0000)

First basis vector : (1.0000, 0.0000, 0.0000)

Second basis vector: (0.0000, 1.0000, 0.0000)

Third basis vector : (0.0000, 0.0000, 1.0000)














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© 2010 ceometric UG. All rights reserved.