What is the best way to print a coin with depth map? [closed]

If I have an image like the one attached, what’s the best way to create an accurate depth map of it? I have photoshop CC and 3ds Max, but I don’t know what settings work best with Slic3r. There is a plethora of settings and combinations to choose from in either programs.

Did anyone do this before? If so, can you share your technique?

• Sadly, it's just about as impossible, as the answers point out. OTOH, if you want to create a lithopane , there are several websites that will do so from your image quite simply. Oct 10, 2018 at 14:06
• @CarlWitthoft lithophane and speedprinting need solid Q&A still - good reminder! Oct 10, 2018 at 15:33

From a single image from this perspective (front view) you cannot map the coin surface in detail. There is reported limited success in estimating the depth of single images, but, this is for images with a clear perspective (e.g. like a picture of a room showing the walls and floor at an angle). In order to map the surface you will need to have multiple images and preferably know the direction of lighting on that object.

People with one eye cannot estimate depth very well, you need two eyes and a trained brain to understand the differences in depth.

• You can create a depth map based on a black and white image, where blacks are lows and whites are highs. My question was related to this.
– NLed
Oct 10, 2018 at 8:13
• @NLed Please add that to your question then. I'm very curious how you then would define how high a white color is and how low the black. If you have a legenda it is easy, but how would you determine that from a single front view.
– 0scar
Oct 10, 2018 at 8:32
• @NLed, your attached image does not have that property. Oct 10, 2018 at 8:42
• @NLed You can from a greyscale picture that is formated in this special way. a B&W photo does not have this property. Oct 10, 2018 at 11:20
• @NLed Yes but the problem is that the image of your coin is not in a black to white scale, it is a color scale with highlights, so you cannot make a heightmap. The stars and the 1899 are placed on a plane surface, but if you make a gray scale image of this and convert to a heightmap you never get the actual coin. This is what Trish and Sean hint at.
– 0scar
Oct 10, 2018 at 17:24

I designed a coin to use as a tokens for a RPG. I decided to make it from scratch instead of making a height map. I tried two different approaches.

Smooth height changes

I found a 3D model of the head I wanted to use on my coin. Then I cut it in two, and placed on of the pieces flat side on top of the coin. I then flattened the head to make it more appropriate for a coin. When I sliced it whit the layer height supported by my printer I noticed that I lost too much of the details in the head.

Layered height changes

I found a picture of the head I wanted to use and drew outline of the different parts of the head that I wanted to include. I then added each drawing with a different thickness to the coin. This gave me a clear drawing on the coin, and is what I ended up printing.

Printing

I printed the coins standing up. 2 of my 42 coins failed because the coin fell over during print. I printed 4 and 4 coins at the time, on placed in each corner of the print surface. I finished one entire coin before starting the next.

• Thanks for answering!! How did you design it? What program did you use?
– NLed
Oct 10, 2018 at 14:16
• I used Fusion 360, which is free for non-comercial use. Oct 12, 2018 at 6:59

If you have a depth map (a raster file with the height at each point), OpenSCAD has the ability to read the height map and create a 3D object. That 3D object can then be exported as an .STL file, and sliced normally.

I have done this (maybe 3 years ago), and it worked well.

This site includes a list of available tools. I probably used one of these, as I could easily convert my particular depth map to a PNG or other image file.

Once the file is in STL format, you can choose how best to print it for your printer.