compressedAttributes

December 17, 2019 ยท View on GitHub

I3S version 1.7 supports compressing the geometryBuffer of Integrated Mesh and 3D Object Layers using Draco compression. Draco compression is optimized for compressing and decompressing 3D geometric meshes and point clouds.

Draco reduces the size of the geometryBuffer payload, thereby reducing storage size and optimizing transmission rate.

All vertexAttributes of a Meshpyramids profile can be compressed with Draco.

The ArcGIS platform currently is compatible with version 1.3.5 of Draco.

cmn::geometryBuffer

Properties

PropertyTypeDescription
encodingstring
Must be:
  • draco
attributesstring[]
Possible values for each array string:
  • position: Draco double meta-data i3s-scale_x, i3s-scale_y. If present, must be applied to x and y coordinates to reverse XY/Z ratio preserving scaling that may have been applied before encoding. (i.e.avoid quantization issue when XY is in degrees and Z is in meters)
  • normal
  • uv0
  • color
  • uv-region: Uses draco::GeometryAttribute::Type::GENERIC with type 4xUINT16. The attribute meta-data key i3s-attribute-type must be set to "uv-region" (string).
  • feature-index: Uses draco::GeometryAttribute::Type::GENERIC with type 1xUINT32. The attribute meta-data key i3s-attribute-type must be set to "feature-index" (string). The feature-ids values must be stored in the feature-index attribute meta-data with key:"i3s-feature-ids" (metata data entry type is array of int32)

Note: properties in bold are required