We have an issue where we have an existing dataset of Sydney build from Lidar scans and when we overlay this data with an Aerometrix photogrammetry Cesium model of Sydney in Unreal, and get a key building aligned in both, we notice that further from the origin the buildings between the 2 data sets becomes further and further apart. That is to say that are not matching correctly. We are pretty sure the Lidar scans are accurate, and what I have found is that applying a small -1.3 degree rotation to the Cesium (aerometrix) data tile will bring it back into alignment.
But why and is this the best approach?
Is it that the northpoint between the 2 datasets is slightly different?
Are we able to change the northpoint in cesium?
I’m not sure. By the time Cesium for Unreal sees the tileset, it’s Earth-Centered, Earth-Fixed coordinates, leaving very little room for interpretation. You might try asking Aerometrex how that particular tileset was produced.