A lithophane maker that shows the light before you print

A lithophane is not a printed photograph. It is a translucent panel whose thickness controls how much light passes through: thin areas glow, thick areas block. That means the useful input is a height field, not a color image. A lithophane maker has to decide which parts of the photo become thin, which become thick, and how much total thickness the printer can reproduce.

DepthCarve estimates relative depth from one photo and lets you invert it, remap the black and white points, and set a base thickness. The result is a height-field slab that can be printed in white filament and backlit. It is not a measured scan, and it cannot recover the back of a head or a hidden side. Treat the preview as a readable interpretation of the photo, not as a physical measurement.

The exported STL is a rectangular panel with a top surface, side walls, and a flat back. It does not include a cylindrical curve, an LED housing, a battery compartment, a stand, or a hanging hole. Those parts belong in a model editor or a separate print design. Adding them after the relief is exported is normal; expecting the generator to invent them is not.

That boundary is deliberate. A curved lithophane lamp needs a different projection and a wall thickness designed around the light source. A flat panel is the honest first product: one image, one thickness range, one test print. If the flat panel reads well, the same depth field can become the starting point for a more complex object later.

Pick a photo with one clear subject, even lighting, and a background that does not compete. Faces work best when the eyes, nose, and mouth are visible and the head is not pressed against the frame. Busy foliage, reflective glass, and a bright window behind the subject can confuse the depth estimate and produce a muddy panel even when the photo looks good on a phone.

Crop before upload. A small face inside a wide room gives most of the panel to the room. For a 100 mm wide ornament, the face should occupy enough of the frame to remain readable at arm's length. Check the inverted preview as well: the brightest areas should be the places you expect to glow, and the darkest areas should form a stable border rather than a noisy cloud.

No generator knows your nozzle, layer height, filament opacity, or light source. Start with a small test panel, print it vertically or at the orientation your printer handles best, and hold it against the intended light. White PLA or PETG at a 0.12-0.16 mm layer height is a common starting point, but the correct thickness range depends on the material and the backlight.

Keep the print test and the file review separate. The free preview answers whether the photo is readable. The test print answers whether the thickness range and the printer produce the glow you want. If the panel is too dark, reduce the maximum thickness or raise the light output; if it is washed out, increase the thickness range. Do not change both at once.