Converting coordinate systems from Realsense D435 sensor to Unity

[Motahar]

Hi, I work with the RealSense D435 sensor, Nuitrack, and Unity.

I know that the sensor coordinate system is right-handed and the Unity coordinate system is left-handed. But the difference is not just about one axis, all three axes have different directions in the two systems. I am wondering how Nuitrack solves this problem and converts coordinate systems, as well as global joints and local joints from the sensor coordinate system to the Unity coordinate system.

Thank you so much

[Stepan.Reuk]

Hello @Motahar

Left or Right-handed Coordinate System?

By default, the origin of coordinates coincides with the position of the depth sensor (given that registration of depth frames and color frames is turned off). Coordinate axes are directed as shown in the image. This system is used by default in the OpenNI framework. [изображение]

The same coordinate system is used in Unity. This is what the conversion from Nuitrack coordinates to Unity coordinates looks like.

[Motahar]

Hi @Stepan.Reuk ,

Thank you for your answer. Now my question is about the coordinate system conversion between the sensor and Nuitrack.

In the post you replied to, the sensor in the picture has a left-handed coordinate system, while the sensor I work with, D435, has a right-handed coordinate system.

So my question is: does Nuitrack use the sensor’s right-handed coordinate system and convert it to left-handed when visualizing joints in Unity, or does Nuitrack use its own coordinate system that is independent of the sensor’s coordinate frame?

Thank you so much