# Azure Kinect point cloud

1 Reputation point
2021-01-15T03:13:45.367+00:00

Hello,

The point cloud is tilted, and the bottom is the floor, and you can see that the floor and the person are tilted.

How we can solve this problem?

Thank you.

Azure Kinect DK
Azure Kinect DK
A Microsoft developer kit and peripheral device with advanced artificial intelligence sensors for sophisticated computer vision and speech models.
288 questions

1. 351 Reputation points
2021-01-29T22:27:37.61+00:00

The depth camera is pointed 6 deg down relative to the color camera.

You can use the IMU to determine the physical angle of the camera to determine the angle of the camera to the floor and make the necessary coordinate adjustments. Alternatively you can do floor detection and make the necessary coordinate adjustments.

2. 351 Reputation points
2021-02-01T21:50:17.897+00:00

@JAMES MORGENSTERN you can use the 3 accelerometers to measure the gravity vector and thus calculate the angle of the camera to the floor

3. 176 Reputation points
2021-02-02T00:23:54.607+00:00

@Quentin Miller well, useful thought. here is my confusion then: the Kinect is oriented pointing down, that is the Z axis is perpendicular to the floor and xy plane is parallel to the floor. The accelerometer readouts are [from your Kinect SDK viewer] : X=9.8, Y=-.2, Z=0.
Since Z is in the direction of the gravity vector wouldnt I expect Z=9.8m/s/s and not the X accelerometer ?.

4. 351 Reputation points
2021-02-02T01:32:32.393+00:00

@JAMES MORGENSTERN well that is most weird. Just checked my Azure Kinect. Laid flat (tripod mount touching table) on the edge of a table (chin hanging over the edge) I am seeing Z=-9.8. I get X as 9.8 if the camera is face down (glass touching table) on the table.

https://learn.microsoft.com/en-us/azure/kinect-dk/coordinate-systems#gyroscope-and-accelerometer