In this tutorial, we’ll be going over the steps for creating your own 3D printable lithophane using the free and open source software, Blender. Lithophanes are three dimensional objects that display an image when a light is shone through them. This tutorial is a primer for getting started with Blender and the final result makes for a great decoration or gift.
You’ll want to start out by choosing the image for your lithophane. Most images will work well so long as they’re reasonably high resolution and don’t have an excessive number of intricate details. For this example, we’ll use a picture of one of our team member’s pets for our lithophane.
Getting started and setting up your image
Being effective in Blender is all about knowing which keyboard shortcuts to use. When you first open the program, there will be three objects in your workspace; a camera, cube, and lamp. We won’t need these so use the ‘A’ key to select all and the ‘X’ key to bring up the delete dialogue. Hit enter to delete the objects.
Now we’ll need to import the image. On your right side panel, you’ll see a checkerboard pattern labeled ‘textures’. Click on the icon and select the ‘New’ option. Select ‘Open’ and navigate to your image.
Creating your grid
Next we’ll need to set up the grid that our lithophane is built from. On your left side panel, navigate to the ‘Create’ tab and select the ‘Grid’ option. Now we need to choose the number of subdivisions for our grid.
Grids in Blender are made up of a number of segments which intersect to form squares. Subdividing a mesh tells Blender how many lines to use for each axis and defines how many squares your grid will be made from. This determines how closely your lithophane will compare to the original image with greater subdivision resulting in higher accuracy.
You’ll want to subdivide your grid using the same aspect ratio as your image. For instance, if the image you imported has a resolution of 1920px x 1080px and thusly an aspect ratio of 16:9, you’ll want to make sure the ratio of X subdivisions to Y subdivisions is 16:9. Our image happens to be a perfect square which makes things a bit easier as the X and Y subdivisions will be the same.
More subdivisions will result in great accuracy but many computers will struggle to handle more than 500 or so in each axis. We’ll be setting the X and Y subdivisions to 400 each which should be more than enough for a high quality lithophane.
Sizing your lithophane
You’ll notice that the grid is still a square after changing the number of subdivisions even if your image may be rectangular. To correct this, hit the ‘N’ key which will bring up the properties panel. Enter your desired X and Y dimensions under the dimensions panel. Note, the default values are in millimeters so entering 100 as both X and Y will create a lithophane that’s a 100mm square.
These dimensions also need to use the same aspect ratio as your image. For example, a 1920 x 1080 image can be divided by 10 to produce dimensions of 192 x 108.
Deforming your mesh
Next we’ll map our image to the grid to create our lithophane. From the right panel, click on the wrench icon and navigate to the ‘Add Modifier’ dropdown. Select the ‘displace modifier’ and again click on the checkerboard icon. Select the image you imported earlier from the dropdown.
Set the strength value to negative two (this seems to be the optimal strength for 3D printed lithophanes) and make sure to hit apply! This will deform your grid using the image you provided and create the basis for your lithophane.
Your mesh is still a two dimensional object so we’ll need to add some thickness in order for it to be 3D printed. We’ll do this by entering edit mode which can be accessed via the ‘tab’ key. From the bottom panel, click on the ‘edge select’ option and select a single point from your mesh.
We’ll use the shortcut ‘Ctrl + shift + alt + m’ to select only the outer edges. Now we’ll hit the ‘E’ key for extrude and then the ‘Z’ key to extrude the edges in the Z-Axis. Extrude your edge upwards an arbitrary amount and hit enter. Note, you’ll want to make sure that the darker regions of your image are facing outwards and the lighter portions are further inwards. If this is backwards for you, undo the extrusion and go the other way.
Next, we’ll align all of the points onto the same Z plane. Hit the ‘S’ key to enter scale mode and then the ‘Z’ key to constrain it to the Z axis. Now enter the number ‘0’ and hit enter. All of your points will align onto the same axis.
To more accurately set your mesh thickness, go back to the properties panel (‘N’ key if it’s disappeared) and look for the ‘Median’ option. Set your Z value to negative 1.5 and finish off your mesh by hitting the ‘F’ key which will cap your outline.
Time to print!
Export your model using the file menu at the top and going to File then Export then STL. To print your lithophane, you’ll want to align one of your edges to be flat on the platform. This improves the accuracy of your lithophane. 3D printers often have greater accuracy in the X and Y axis than they do in the Z axis unless layer heights are set to very fine resolutions.
Your lithophane may look uneventful straight off of the printer but shining a light behind the printed object will illuminate your image! We printed ours on the Formlabs Form 2 in a new matte White Resin and it came out great. We’d love to see your results so make sure to upload your successful lithophanes to Pinshape.