3D Sliced Engravings¶
Galvo users without a live Z-axis have the ability to make "2.5D" engravings with LightBurn and their galvo, producing objects with tactile and visual depth. LightBurn calls this mode "3D Sliced" due to the similarity to 3D printing slicers; where horizontal slices are deposited by 3D printers, LightBurn allows subtractive layer-by-layer operations.
3D Sliced mode uses greyscale images called powermaps to create depth in the engraving. Darker shades of grey will be cut with more passes and become deeper, while lighter shades of grey will be cut with fewer passes, making them shallower. These can be created by hand, although tools like STL2PNG that generate raster images from STL files are often used to make more complex depth maps. The greyscale powermap can be imported to LightBurn like any other image. 3D Sliced mode uses the depth map to generate up to 256 steps of engravings, with impressive results.
First, produce a greyscale heightmap image in any tool you choose and import it to LightBurn.
Open the Cut Settings Editor for the layer the image you've imported is on, and change it's type to "3D Sliced".
Next, change the number of passes entry to the quantity you intend to use for this operation. The more passes, the higher the effective resolution can be, though reducing the power such that it doesn't go deeper may be needed. Think of this as "layer height" for 3D printers.
More complex, larger designs may take more time to process, because of the complexity of generating each pass. If you see this dialog, please be patient as your computer may need some time to prepare your design.
Check the preview to confirm your design is behaving as you're expecting. If you use the play button, you should see your design render from the bottom to the top, with black indicating the engraved portion for each layer.