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Bounding Boxes

Description​

Every mobject has a "bounding box", which is the smallest rectangle that surrounds it completely.

Details​

Under the hood, spatial relations use the bounding boxes of the mobjects in the operation. These same operations are commonly useful for adding labels or arrows or dots at specific locations on the bbox. The "complete" bounding box is represented as 9 points: 4 corners, 4 edge points, and 1 center.

Example 1

The bounding box points for a mobject can be accessed in the following ways:

  • mobject.right: the midpoint on the right edge
  • mobject.left: the midpoint on the left edge
  • mobject.top: the midpoint on the top edge
  • mobject.bottom: the midpoint on the bottom edge
  • mobject.center: the center of the bbox
  • mobject.get_corner(UR): upper right corner
  • mobject.get_corner(UL): upper left corner
  • mobject.get_corner(DL): down (lower) left corner
  • mobject.get_corner(DR): down (lower) right corner

These operations return a Point3D (e.g. [1, 0, 0])

The width and height of the bbox can also be accessed as mobject.width and mobject.height respectively.