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RTCQuaternionDecomposition(3) Embree Ray Tracing Kernels 3 RTCQuaternionDecomposition(3)

NAME

RTCQuaternionDecomposition - structure that represents a quaternion


  decomposition of an affine transformation

SYNOPSIS

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;
};

DESCRIPTION

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.

EXIT STATUS

No error code is set by this function.

SEE ALSO

[rtcSetGeometryTransformQuaternion], [rtcInitQuaternionDecomposition]