I liked how he challenged our edge-detection NN in lesson 3. With a gray paper, it is possible to use a dark and white pencils, making 2D looks like 3D. He does

I liked how he challenged our edge-detection NN in lesson 3. With a gray paper, it is possible to use a dark and white pencils, making 2D looks like 3D. He does it again in lesson 8, drawing some leaves.