Manpages - RTCQuaternionDecomposition.3embree3

  RTCQuaternionDecomposition - structure that represents a quaternion
    decomposition of an affine transformation

  struct RTCQuaternionDecomposition
  {
    float scale_x, scale_y, scale_z;
    float skew_xy, skew_xz, skew_yz;
    float shift_x, shift_y, shift_z;
    float quaternion_r, quaternion_i, quaternion_j, quaternion_k;
    float translation_x, translation_y, translation_z;
  };

The struct RTCQuaternionDecomposition represents an affine transformation decomposed into three parts. An upper triangular scaling/skew/shift matrix

\[ S = \left( \begin{array}{cccc} scale_x & skew_{xy} & skew_{xz} & shift_x \\ 0 & scale_y & skew_{yz} & shift_y \\ 0 & 0 & scale_z & shift_z \\ 0 & 0 & 0 & 1 \\ \end{array} \right), \]

a translation matrix

\[ T = \left( \begin{array}{cccc} 1 & 0 & 0 & translation_x \\ 0 & 1 & 0 & translation_y \\ 0 & 0 & 1 & translation_z \\ 0 & 0 & 0 & 1 \\ \end{array} \right), \]

and a rotation matrix R, represented as a quaternion

/quaternion/~/r/~ + /quaternion/~/i/~ i + /quaternion/~/j/~ i + /quaternion/~/k/~ k

where i, j k are the imaginary quaternion units. The passed quaternion will be normalized internally.

The affine transformation matrix corresponding to a RTCQuaternionDecomposition is TRS and a point p = (/p/~/x/~, /p/~/y/~, /p/~/z/~, 1)^/T/^ will be transformed as

p/′ = /T R S p.

The functions rtcInitQuaternionDecomposition, rtcQuaternionDecompositionSetQuaternion, rtcQuaternionDecompositionSetScale, rtcQuaternionDecompositionSetSkew, rtcQuaternionDecompositionSetShift, and rtcQuaternionDecompositionSetTranslation allow to set the fields of the structure more conveniently.

No error code is set by this function.

[rtcSetGeometryTransformQuaternion], [rtcInitQuaternionDecomposition]