Shadow Lamp STL Generator

A shadow lamp is a small box that hangs on the wall with one LED inside. Its four side panels are stencils: where the panel is solid, it blocks the light; where it is open, the light reaches the wall. Seen from the room, the wall around the box shows your picture as a large shadow, many times the size of the lamp. This generator designs that box from a single image: it works out what each of the four panels has to look like so that, from the LED's point of view, together they draw your image on the wall.

The panels are not flat cut-outs. Every opening is a projective tunnel: its walls lean along the light rays, so a ray that passes the inner edge of a hole also clears the outer edge, and the shadow stays sharp even though the panel is several millimetres thick. Thin bridges are kept at least 2 mm wide and gaps at least 1 mm, the shape is joined into one printable piece per panel, and the corners overlap so no light leaks between panels. The LED sits on a post in the front cap and faces the wall, with USB-C or 3 × AAA power and a switch; the back plate hangs on two keyholes.

What you upload decides how the pattern is made. A ready silhouette or logo is used as it is. A photo is cut out from its background with a segmentation model, and in Detailed mode the dark details inside the shape (eyes, hair, folds of clothing) are kept as small shadows, so faces stay recognisable. Before you pay you see the result in a lit 3D preview: turn the light off and on, explode the lamp into its six parts and look at the shadow on the wall from any angle.

The download is a ZIP with six STL files sized for a Bambu Lab A1 or any printer with a 256 mm bed, printable in PLA without supports, four small fit-test pieces to check tolerances on your printer, and an assembly guide. Print the panels in black matte PLA: in our renders a white lamp glows like a lantern and the shadow loses most of its contrast. Commercial use is included, so you can print and sell lamps made from your own images.