Have you seen the subsurface laser engravers that create those 3d acrylic point cloud portrait things? I looked into them while doing some research on this. The

Have you seen the subsurface laser engravers that create those 3d acrylic point cloud portrait things? I looked into them while doing some research on this. They basically use a focusing lens to create the hotspot at a point within the block of acrylic. They can do up to 20,000 points per second in a plane by aiming some galvos, and the material is moved slowly to create the 3rd dimension. The granular material plus binder combinations are essentially unlimited. I even thought of making 3d printed treats by using sugar with water binder, or rice crispies with a food safe binder.