You can use mesh files as a reference for your design with solid bodies, or modify it with boolean tools, transformations, and Visualization.
To use mesh data, save it in a mesh file such as STL or 3MF, and import it into Shapr3D.
For example, you can import a mesh ring base into Shapr3D and extrude a sketch to cut away or subtract from the mesh body. You can also use the mesh body to cut from existing solid bodies.
This is how the end product should look:
Note: You can only use boolean operations with closed (solid) mesh bodies, not open (sheet) mesh. Regardless of the type of boolean operation you use with a mesh body, the body will always stay a mesh body.