Billboard using alignedAxis not aligned with the path direction in 2D mode.

[johnnylc]

Using the CZML sandcastle(https://sandcastle.cesium.com/?src=CZML%20Path.html), I set

alignedAxis: {
        velocityReference: '#position'
}

to billboard to make billboard's direction following the path direction.

In 3D mode the result seems ok, but in 2D mode the billboard's heading is not aligned with the path's direction.
The same scenerios in 2D and 3D mode are as below:
2D:

3D:

Sandcastle example:
https://sandcastle.cesium.com/?src=CZML%20Path.html

Browser:
Chrome 108.0.5359.125
Operating System:
Windows 11

[ggetz]

I'm getting what looks like correct results in both 3D and 2D if I replace the following line in BillboardCollectionVS.glsl:

            vec4 projectedAlignedAxis = czm_modelViewProjection * vec4(alignedAxis, 0.0);

with

            vec4 projectedAlignedAxis = czm_modelView3D * vec4(alignedAxis, 0.0);

czm_modelView3D should account for differences in the camera between 3D and 2D mode.

[johnnylc]

Thanks for the fix. It works.