OptaPlanner 3D Bin Packing Solver

Project Overview

Built a dedicated OptaPlanner stack for industrial 3D bin packing so fulfillment teams can auto-generate container layouts instead of hand-curating placements. The workload ingests standard benchmark manifests, normalizes part metadata, and produces collision-safe container layouts that already respect gravity and stacking constraints. Stakeholders inspect any run through a lightweight OBJ exporter, keeping sensitive operational data out of shared viewers.

Solver Architecture

• Added spatial indexes and specialized data structures that answer “first-fit” queries without scanning every candidate, which keeps the score director responsive on large search spaces.
• Injected a purpose-built construction heuristic so the first feasible layout honors gravity, stacking constraints, and support-aware ordering before the local search begins.
• Tuned the constraint provider to balance surface coverage, unused volume, and soft penalties (rotations, unsupported overhangs, handling preferences).

Custom Move Set

• Authored specialized move families with probability weights so OptaPlanner focuses on high-value neighborhoods instead of exploring every combinatorial permutation the default moves would generate.
• Added configurable “items to ruin” limits inside the large-neighborhood move so deeper reshuffles happen without restarting the entire search.
• Layered tabu-based acceptors and tuned foragers so diversification kicks in only when improvements plateau, shortening convergence time dramatically.

Impact

• Handles dense multi-container workloads that previously stalled default OptaPlanner moves because of the exploding search space.
• Produces placements that can be reviewed visually via OBJ exports, speeding up validation with operations teams.

Technologies & Concepts