An Open-Source Pipeline for Runtime-Optimized Heritage Photogrammetry in Game Engines

Abstract. This paper presents Mesh2Tile, an open-source pipeline that converts photogrammetric meshes into runtime-optimized 3D Tiles for interactive visualization in game engines. Photogrammetry produces high-polygon meshes that remain difficult to deliver at scale through interactive platforms. Cloud-based conversion services like Cesium Ion provide a path to the OGC 3D Tiles format but impose cost barriers and raise data sovereignty concerns for confidential heritage projects. Existing open-source converters rely on uniform spatial partitioning, export redundant textures with every tile, and offer limited control over LOD generation. Mesh2Tile leverages Blender's Python API to perform adaptive octree tiling driven by triangle density, per-tile texture baking that eliminates texture redundancy, and parallel processing to generate georeferenced 3D Tiles from OBJ meshes. The pipeline is validated through a case study of the Bytown Museum Commissariat Building on the Rideau Canal UNESCO World Heritage Site. It is processed at three scales from 900 thousand to 90 million triangles. Results demonstrate linear scaling of processing time, up to 62% file size reduction for larger models, and successful runtime streaming in Unreal Engine 5 through the Cesium for Unreal plugin at 120 FPS with comparable tile balance to Cesium Ion's commercial output. The pipeline enables institutions to maintain full control over sensitive heritage data while achieving performance suitable for interactive visualization.