Added TileBoundingVolumes class to Cesium3DTilesContent, making it easier to create the rich bounding volume types in CesiumGeometry and CesiumGeospatial from the simple std::vector representations in Cesium3DTiles
Added transform method to CesiumGeometry::BoundingSphere.
Added toSphere, fromSphere, and fromAxisAligned methods to CesiumGeometry::OrientedBoundingBox.
Added TileTransform class to Cesium3DTilesContent, making it easier to create a glm::dmat4 from the transform property of a Cesium3DTiles::Tile.
This is a PR into #747 so merge that first.
Fixes #647
TileBoundingVolumesclass toCesium3DTilesContent, making it easier to create the rich bounding volume types inCesiumGeometryandCesiumGeospatialfrom the simplestd::vectorrepresentations inCesium3DTilestransformmethod toCesiumGeometry::BoundingSphere.toSphere,fromSphere, andfromAxisAlignedmethods toCesiumGeometry::OrientedBoundingBox.TileTransformclass toCesium3DTilesContent, making it easier to create aglm::dmat4from thetransformproperty of aCesium3DTiles::Tile.