@OldPaddy I'm not sure I understand the issue. Can you describe specifically how to setup an easy test case?

@micahpearlman
I'm sorry I didn't make it clear enough.
I tested initial turtlebot3 scene like following image.
In this case, I changed the "Min Angle Degree" with lidar-2d script to 90 degree.
So the lidar FOV is from 90 to 360 degree. It doesn't match Unity and Rviz display.

Turtlebot3 tested scene. The display to the left is Unity, the right is Rviz. The upward direction on the image is forward direction.

You can get the same result by manually adjusting the turtlebot definition.

In lidar-2d Transform, set Rotation to X=180, Y=180, Z=0

Result:

You can get the same result by manually adjusting the turtlebot definition by doing the following:

In lidar-2d Transform, set Rotation to X=180, Y=180, Z=0

Result:

@alex-ssom Thank you for your description.
I think it's strange the places of the lidar-2d rays are mismatch.

Please let me know if my understanding is wrong.

@OldPaddy thanks, works for me. Its indeed a bug in ZOLIDAR2D.cs