Function leap_sys::LeapScaleOffsetMatrixEx

source · [−]
pub unsafe extern "C" fn LeapScaleOffsetMatrixEx(
    hConnection: LEAP_CONNECTION,
    hDevice: LEAP_DEVICE,
    camera: eLeapPerspectiveType,
    dest: *mut f32
)
Expand description

\ingroup Functions

Returns the appropriate scale and offset coefficients required to project normalised Rectilinear coordinates to image-scale coordinates.

This is composed of a 4 x 4 matrix of the form:

scale_x, 0, 0, offset_x, 0, 1, 0, 0, 0, 0, scale_z, offset_z 0, 0, 0, 1

This matrix is specific to the size of the current image as contained within LEAP_IMAGE.

In practical terms, use this matrix in combination with normalised rays to project 3D points into a rectilinear image space (i.e. to visualise hands on an undistorted image).

The pipeline would be:

  1. Take 3D points from hand tracking.
  2. Apply an extrinsic transformation to a specific camera’s coordinate system (@sa LeapExtrinsicCameraMatrixEx)
  3. Apply a perspective division to transform 3D points to rays.
  4. Apply the ScaleOffset matrix to these points.

These points will now be in the correct coordinate system consistent with the undistorted rectilinear image provided by LEAP_IMAGE::distortion_matrix.

@param hConnection The connection handle created by LeapCreateConnection(). @param hDevice A device handle returned by LeapOpenDevice(). @param camera The camera to use, a member of the eLeapPerspectiveType enumeration @param[out] dest A pointer to a single-precision float array of size 16, containing the coefficients of the 4x4 matrix in Column Major order @since 5.x.x