Rotations Question ...

[Slastraf]

I need more data on how the Ultra Engine works.
I had great success combining the Vicon SDK headers, dlls ...,  inside Ultra Engine.
It is used to track real life objects into virtual space.
The tracking translation works fine, however I have great issues adjusting the details.

The Vicon SDK Documentation says this about their conventions

Units
"Positions are expressed in millimeters. Rotation is expressed in radians."

When I convert from radians to degrees to be applicable inside Ultra Engine, there are various issues, such as the object flipping at certain angles etc. I convert by multiplying each vector component by (180 / 3.14)
Instead of Euler XYZ there are also functions to get the Quat , x y z w  . This had no flipping issues but the axis are not aligned.

"The quaternion is of the form (x, y, z, w) where w is the real component and x, y and z are the imaginary
components. N.B. This is different from that used in many other applications, which use (w, x, y, z)."
Ultra Engine uses x,y,z,w as i remember from the documentation. However the axis are still flipped.

I made a video to show how the tracking currently works:
https://ody.sh/b85p8I5GK8 (odysee)

SetAxisMapping() :
Vicon Data uses a right-handed coordinate system, with +X forward, +Y left, and +Z up


I am at a loss at how to properly implement this.

[Slastraf]

Update Ultra
The engine uses a left-handed coordinate system. The X axis points to the right, the Y axis points up, and the Z axis points forward.
            this->client->SetAxisMapping(
                ViconDataStreamSDK::CPP::Direction::Right,
                ViconDataStreamSDK::CPP::Direction::Up,            // Y-up
                ViconDataStreamSDK::CPP::Direction::Forward
            );

the rotation axis are still wrong.
I have a reference live view inside vicon tracker, and the rotations are very different

[Slastraf]

(Ultra Engine Discord)

[Slastraf]

//radians to degrees
rot.x = UltraEngine::Degrees(rot.x);
rot.y = UltraEngine::Degrees(rot.y);
rot.z = UltraEngine::Degrees(rot.z);

// prevent gimbal lock
this->model->SetRotation(0, 0, 0);
this->model->Turn(rot.x, 0.0, 0.0);
this->model->Turn(0.0, rot.y, 0.0);
this->model->Turn(0.0, 0.0, rot.z);

this is example code to prevent gimbal lock. i do no longer use quaternions. but from radians eulers converted instead.