Unexpected BoundingBox.Min/Max Value When Using Union()

Rhino Developer
,
1

var bbox = new BoundingBox();
bbox.Union(new Point3d(1, 1, 1));
bbox.Union(new Point3d(2, 2, 2));

// Expected: bbox.Max = (2,2,2), bbox.Min = (1,1,1)
// But bbox.Min = (0,0,0)

// I know why, but shouldn’t it work differently?

2

There are four BoundingBox constructors. All appear to want some kind of argument inside the parentheses.

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It looks like if you don’t supply an argument, RhinoCommon automatically adds 0,0,0 as a point and makes the box with that:

import Rhino

bbox=Rhino.Geometry.BoundingBox()
print(bbox.Min,bbox.Max)
bbox.Union(Rhino.Geometry.Point3d(1, 1, 1))
print(bbox.Min,bbox.Max)
bbox.Union(Rhino.Geometry.Point3d(2, 2, 2))
print(bbox.Min,bbox.Max)

However it also appears you can force a non-defined bounding box by using Rhino.Geometry.BoundingBox.Unset. Then your code will work:

import Rhino

bbox=Rhino.Geometry.BoundingBox.Unset
print(bbox.Min,bbox.Max)
bbox.Union(Rhino.Geometry.Point3d(1, 1, 1))
print(bbox.Min,bbox.Max)
bbox.Union(Rhino.Geometry.Point3d(2, 2, 2))
print(bbox.Min,bbox.Max)
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