Introduction

3D Tiles is an OGC open standard being adopted by across a broad range of applications. The standard allows for efficiencies in the rendering and streaming of 3D content at any size. It covers 3D geospatial content such as Photogrammetry, 3D Buildings, BIM/CAD, Instanced Features, and Point Clouds.

3D Tiles data is stored as tilesets which can contain any combination of content organised into a special data structure. Using 3D Tiles brings the benefit of only the visible and most important data being streamed and therefore reduces demand on resources.

The visibility of data is customisable and EMT ATLAS has optimised the open standard parameters to bring users the best performance for their data.

ATLAS’s support for 3D Tiles

3DTiles Feature/Extension	Supported
Core 1.0 .b3dm	Yes
Core 1.0 .i3dm	No
Core 1.0 .pnt	Yes
3DTiles_batch_table_hierarchy	Partial
3DTiles_content_gltf	Yes
3DTiles_imlicit_tiling	No
3DTiles_multiple_contents	No
3DTiles_bounding_volume_S2	No
3DTiles_metadata	Partial
KHR_draco_mesh_compression (glTF specification)	Yes
EXT_mesh_features (glTF specification)	No
EXT_feature_metadata (glTF specification)	No
KHR_texture_basisu (glTF specification)	No
KHR_materials_unlit (glTF specification)	No

3D Data Compression

3D Tiles generated by ATLAS have built in compression:

For 3D Models Tiles (b3dm) - Meshopt + gzip
For Point Clouds (put) - Draco

Coordinate Systems within ATLAS

ATLAS supports all EPSG and ESRI based input Coordinate Reference Systems (CRS). Custom projections and specific grid files can also be specified. All 3D data processed by ATLAS is re-projected by default to EPSG:4978.