We have been using MOI3D to create primitives for an almost free ($6 donation) surface modeling program called MeshMolder. https://www.meshmolder.com/

In these images we see a Sphere deformed by pushing and pulling points in MOI3D then exported as .OBJ. It was then imported to Meshmolder for surfacing with a rough texture. The whole process took just a few minutes. The pushing and pulling can cause surface breaks which can be fixed in Meshmolder.

MOI3D and MeshMolder make for a very good combination of tools. Ultimately, the developer of Meshmolder hopes to have a similarly priced rendering engine.