coordinate rotation issue in b3dm

CesiumJS
1

I need to read 3dtiles file in my project , the 3dtiles is created by ContextCapture.

I can read the b3dm file out now ,get the gltf json content,and the bv_pos,bv_uv,bv_ind,and the other vector data.

I need project the point location to Geography Coordinate , the gltf json content contain a CESIUM_RTC value, project the CESIUM_RTC point to Geography Coordinate is in right place ,the other point add the CESIUM_RTC as translation, project to Geography Coordinate is in wrong place, it seems like there is a rotation in more than one way, Any one can help me to solve the problem,thanks!

the addition file is the gltf json file and the screenshot in cesium.

diplay in cesium.png
diplay in cesium.png868×719 855 KB

gltf json in b3dm.zip (1.09 KB)

2

Hey, thanks for providing sample data! It sounds like you might need to apply Transforms.eastNorthUpToFixedFrame to your RTC center before applying it as an offset.

If that doesn’t work, can you provide a working code example so I can see exactly which points are getting the correct offset and which aren’t?

3

thank you for your response,I have get the way to rotation,rotation at X with 90 degree, it means y=-z,z=y.

在 2018年9月19日星期三 UTC+8下午7:46:36，Omar Shehata写道：

4

You’re right! It looks like this is because glTF defines a right-handed coordinate system with the y-axis up whereas 3D Tiles uses a z-up system.

Here’s more info in the spec: https://github.com/AnalyticalGraphicsInc/3d-tiles/tree/master/specification#gltf

Thanks for posting your solution!