Plater is a 3D printer parts placer and optimizer that takes STL files and configuration parameters to generate optimized print plates. It uses a heuristic based on greedy algorithm with brute force to arrange parts on print plates, minimizing the number of plates needed. The system features both a Qt-based GUI for interactive use and a command-line interface for automation. The architecture cleanly separates the core placement algorithm (in the plater/ library) from the user interface (in gui/), with the core library handling STL parsing, bitmap-based part representation, and the optimization algorithm. The placement algorithm pixelizes parts into bitmaps, applies spacing through dilation, and uses a gravity-inspired scoring system to position parts, running multiple iterations with different parameters to find the optimal solution.