Houdini - Selecting With Bounding Box

Use the relbbox function in a Group Expression to select points at the “extremities” of a geo’s bounding box.

E.g. the “front facing” points here are +1 on the z-axis:

relbbox(0, @P).z == 1

And the “back facing” ones would be z == 0.

The “top” points are +1 on the y-axis:

relbbox(0, @P).y == 1

Using the same expression lets us also conveniently select the “topmost” point on a sphere:

• houdini
• vex