To create some models you first need to add primitive shapes. You can either use the predefined one (as for the box) or create it yourself by defining the vertices (as for the pyramid).

Later you need to combine the individual meshes into a single one. You can offset, rotate, scale or clone them to place them in desired positions.

Finally, you can style the whole mesh as well as specific components. You can apply different colors and textures and style the edges.