A very easy one, but looks complicated. I start in Blender with Math Function addon > Dodecahedron, and parameters set to default value. Immediate, I begin the extrude all faces. Then to select some of the new faces and do a large inset, and extrude those again. Then I subdivide all sides, and use the knife to cut edges where I wish for the frame lines to exist. Then a Wireframe modifier to convert into a skeleton of all edges, and a Solidify modifier to thicken the skeleton edges. The end is the object you see, after render in Cycles, of course! EASY. Give it a try in Blender, and create a cool structure! Merci!