A little fun with the extrude button across a wavy membrane.

Preliminary sketch of an octahedron.

Here is a quick exercise I did to study intersections from cylinders to spheres.

The following were sketches I did a while back changing the template to Google Sketchup's crayon or charcoal, if I recall correctly. It imitates looser line in a sketch.

Wavy Cube 2

After reducing the wave amplitude.