Solids are the fully enclosed, watertight shapes at the top of the OCCT hierarchy, and the only ones that can be reliably 3D printed or handed to a manufacturer. A solid has a defined inside and outside, which is what makes boolean operations, volume calculations and wall thickness meaningful. These pages cover the solid primitives - boxes, spheres, cylinders, cones - creating solids from closed shells, and measuring properties such as volume and centre of mass. They also cover the checks that tell you whether a shape is genuinely a valid solid before you export it.
Solids are closed, watertight volumes in OCCT and the shape kind most downstream operations expect. Learn how to create them from primitives and from shells, and how to check one is valid.
Learn how to get volume and surface area of a solid