A perfect model on screen can turn into a useless miniature when 3D printed. This common problem in video game development, when creating physical prototypes or merchandise, usually has a simple culprit: a unit incompatibility between the design software and the manufacturing machine. The heart of the failure lies in the G-Code commands G20 (inches) and G21 (millimeters). If your file is exported in inches but the printer reads millimeters, all movements will be 25.4 times smaller, ruining the piece.
The technical solution: export flow verification 🔧
The solution is systematic and must be applied at two critical points. First, configure your slicing software (Cura, PrusaSlicer, etc.) to always export in millimeters (mm). Second, and crucial, open the generated G-Code file with a text editor and verify that the first lines include the G21 command. This code sets the machine to millimeter mode. If you find a G20, replace it with G21. Additionally, ensure consistency in the creation chain: confirm that the units in your DCC (Blender, Maya, 3ds Max) are correctly configured before exporting the STL or OBJ, so that the slicer interprets the real dimensions.
An essential step in the art pipeline ✅
More than a technical detail, this verification is a mandatory quality control step in the video game art pipeline when deriving to physical manufacturing. Including G-Code review in the export checklist prevents loss of time, material, and costs. A file with the correct units ensures that the artistic effort materializes faithfully in the real world, whether for a collectible prototype, a presentation piece, or development tools.
How to detect and fix the scale error between units G20 (inches) and G21 (millimeters) that ruins our 3D prints of video game models?
(PS: game jams are like weddings: everyone happy, no one sleeps, and you end up crying)