VkSRTDataNV(3)

Name

VkSRTDataNV - Structure specifying a transform in SRT decomposition

C Specification

An acceleration structure SRT transform is defined by the structure:

// Provided by VK_NV_ray_tracing_motion_blur
typedef struct VkSRTDataNV {
    float    sx;
    float    a;
    float    b;
    float    pvx;
    float    sy;
    float    c;
    float    pvy;
    float    sz;
    float    pvz;
    float    qx;
    float    qy;
    float    qz;
    float    qw;
    float    tx;
    float    ty;
    float    tz;
} VkSRTDataNV;

Members

sx is the x component of the scale of the transform
a is one component of the shear for the transform
b is one component of the shear for the transform
pvx is the x component of the pivot point of the transform
sy is the y component of the scale of the transform
c is one component of the shear for the transform
pvy is the y component of the pivot point of the transform
sz is the z component of the scale of the transform
pvz is the z component of the pivot point of the transform
qx is the x component of the rotation quaternion
qy is the y component of the rotation quaternion
qz is the z component of the rotation quaternion
qw is the w component of the rotation quaternion
tx is the x component of the post-rotation translation
ty is the y component of the post-rotation translation
tz is the z component of the post-rotation translation

Description

This transform decomposition consists of three elements. The first is a matrix S, consisting of a scale, shear, and translation, usually used to define the pivot point of the following rotation. This matrix is constructed from the parameters above by:

The rotation quaternion is defined as:

: R = [ qx, qy, qz, qw ]

This is a rotation around a conceptual normalized axis [ ax, ay, az ] of amount theta such that:

: [ qx, qy, qz ] = sin(theta/2) × [ ax, ay, az ]

and

: qw = cos(theta/2)

Finally, the transform has a translation T constructed from the parameters above by:

The effective derived transform is then given by

: T × R × S

Document Notes

For more information, see the Vulkan Specification.

This page is extracted from the Vulkan Specification. Fixes and changes should be made to the Specification, not directly.