A programmable pipeline for multi-material fabrication

Abstract

3D printing hardware is rapidly scaling up to output continuous mixtures of multiple materials at increasing resolution over ever larger print volumes. This poses an enormous computational challenge: large high-resolution prints comprise trillions of voxels and petabytes of data and simply modeling and describing the input with spatially-varying material mixtures at this scale is challenging. Existing 3D printing software is insufficient; in particular, most software is designed to support only a few million primitives, with discrete material choices per object. In this body of work I present OpenFab, a programmable pipeline for synthesizing multi-material 3D printed objects that is inspired by RenderMan and modern GPU pipelines. The pipeline supports procedural evaluation of geometric detail and material composition by using shader-like fablets. The pipeline allows models to be specified easily and efficiently. Additionally, I describe a streaming architecture for implementing OpenFab; only a small fraction of the final volume is stored in memory and output is fed to the printer with little startup delay. I demonstrate the OpenFab pipeline and programming model on a variety of multi-material objects.