https://github.com/AnalyticalGraphicsInc/3d-tiles/tree/master/TileFormats

Each tile starts with a 4-byte ANSI string, magic


Batch Table
	JSON Header (UTF8), Binary Body
	bound to tile fomats (specified , and batch lenght)
	1. Array of values "name": ['name1', "name2"]
	2 referenc in binary (offset, type..) -> float vec3 -> array
	
Feature Table
	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
	batchtable, featuretable, BinaryGLTF
	Batchtable contains model specific MetaData (styling, ..)
	every vertex has a batchID (technique parameter sematic _BATCHID)
	
Instanced 3D Model .i3dm
	rendering slight variations (position ), same model with properties
	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
		Normal up/right
		Scale
		Batch_ID 
	x is right, y up, z forward
	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
	Composites can contain compoites

Vector Data
	normal Geometry points, polylines, polygons
	no specs, just links to cesium 
	http://cesiumjs.org/tutorials/Geometry-and-Appearances/
	
OpenStreetMap
	Cesium uses Batched 3D Model
	
MAssiv Model
	heavywight Models in contrat to Batchend 3d Model with large number of individual models
	steht nicht viel zu dem Format
	
UnrealGLTFLoader
	https://github.com/RobertPoncelet/UnrealGLTFLoader
	uses Tiny glTF Loader
	studium Projekt
	code, naja, Imnport static mesh ist 400 Zeilen lang
	4.12
		läd basic mesh, stürtzt häufig ab, keine Texturen
	4.14 static mesh hat sich geändert -> rewrite auf static mesh component mal sehen
	
	
Tiny glTF Loader
	gltf & binary gltf
	currently no skin
	uses libraries:
		picojson.h 
		base64
		stb_image.h