Are you talking about a boolean, or CSG (constructive solid geometry)?
If you have polygons, the boolean sop will trivially perform booleans. If you are after a perfect sphere subtracting from a perfect cube, then no there is no implicit boolean such old renderman CSG.
Thanks mate, that does it, and indeed i don't need to use a perfect sphere!
But now i realize i also want to do something else which is a little more tricky, and may not even be possible in Houdini……..
Please consider the two pictures below.
In the first, we have a similar set-up to my first post, and if i use a boolean subtract on it (and change the sphere to polygon), it'll take a bite out of the cube which is roughly a quarter of the volume of the sphere.
But now take a look at the second picture. This is exactly the same scene, only the camera has been moved to a different position.
Again, we're going to delete part of the box. But this time, instead of using a boolean, i want to employ a laser cutter which fires out of our camera, and will cut away only the part where we can see the sphere and box intersecting from this camera angle. It will keep on cutting in a straight line from the camera, all the way through the cube.
So we'll end up with a lot less volume removed from the box, and with a very different shape.
And although we “know” that there is a much larger area than we can see where the sphere and box intersect, only the part we can actually see will be removed.
