A Feature Table describes position and appearance properties for each feature in a tile. The Batch Table, on the other hand, contains per-feature application-specific metadata not necessarily used for rendering.
header + binary
A Feature Table describes position and appearance properties for each feature in a tile.
The Batch Table, on the other hand, contains per-feature application-specific metadata not necessarily used for rendering.
header + binary (siehe batch table)
Batched 3D Model .b3dm
batchLenght number of features (models)
magic - version - byteLenght - batchTableJSONByteLenght -batchTableBinaryLenght -batchLenght
batchTable, BinaryglTF
batchtable, featuretable, BinaryGLTF
Batchtable contains model specific MetaData (styling, ..)
every vertex has a batchID (technique parameter sematic _BATCHID)
Instanced 3D Model
Instanced 3D Model .i3dm
rendering slight variations (position ), same model with properties
inludes feature table and batch table
batchtable, featuretable, BinaryGLTF or url to gltf
maps well to Opengl ANGLED instance arrays https://www.khronos.org/registry/webgl/extensions/ANGLE_instanced_arrays/
Semantics:
Position
...
...
@@ -26,8 +30,45 @@ Instanced 3D Model
Scale
Batch_ID
x is right, y up, z forward
unreal kann in irgendeiner weise instancing
octet further reading: http://jcgt.org/published/0003/02/01/
TODO: unreal Instancing, gibt da wohl was
TODO: octet further reading: http://jcgt.org/published/0003/02/01/
Point Cloud
featureTable, batch table
jeder punklt ein feature
Sematics: Position, RGBA, Normale, BatchID ...
Composite .cmpt
different tiles into node
tile Array
indentifaction by inner tile header (magic) and leanght
