"Also can not turn an object into a negative and subtract from another object. So simple in Infini-D why can't Carrara do it? " bluetone's description is correct. However... If you are used to doing it in Infini-D, Carrara does it differently. In Infini-D the booleans were "renderd booleans" in that they only showed up when you rendered (with ray tracing only) the objects. In Infini-D if you set the cube to positive and the sphere to negative when you rendered the sphere would be subtracted from the cube but the two whole shapes (cube & sphere) still existed. The geometry was not actually changed. This was visiable in the wireframe. In Carrara when you do a boolean the object's geometry is changed forever. Subtract a sphere from a cube and you're left with an entirely new piece of geometry. The sphere will be totally gone and the cube actually altered. Infini-D's way of doing it was kinda cool in that you could animate booleans but got kind of cumbersome in the sense that if you used a lot of booleans in a scene you'd have a lot of "negative" shapes that were still actually there cluttering up the scene. When doing it in Carrara be sure to make a back up copy of your model before you make any boolean changes. No matter what you start out with (a primitive, an object you made in the spline modeler) once you boolean you will be left with a vertex object. If it was a spline object you'll no longer be able to edit it in the spline modeler.