scenepic::Transforms Namespace Reference

Functions
Transform	scale (float scale)
	Creates a 3D homogeneous scale matrix. More...
Transform	scale (const Vector &scale)
	Creates a 3D homogeneous scale matrix. More...
Transform	translate (const Vector &vec)
	Creates a 3D homogeneous scale matrix. More...
Transform	rotation_matrix_from_axis_angle (const Vector &axis, float angle)
	Creates a 3D homogeneous scale matrix from axis and angle. More...
Quaternion	quaternion_from_axis_angle (const Vector &axis, float angle)
	Convert rotation axis and angle to a quaternion. More...
std::pair< Vector, float >	axis_angle_to_align_x_to_axis (const Vector &axis)
	Find the axis and angle of rotation that will ensure the x-axis aligns with the provided axis. More...
Quaternion	quaternion_to_align_x_to_axis (const Vector &axis)
	Creates a quaternion rotation vector that will ensure the x-axis aligns with the provided axis. More...
Quaternion	quaternion_multiply (const Quaternion &a, const Quaternion &b)
	Multiply two quaternions. More...
Transform	rotation_to_align_x_to_axis (const Vector &axis)
	Creates a 3D homogeneous rotation matrix that will ensure the x-axis aligns with the provided axis. More...
Transform	rotation_about_x (float angle)
	Creates a 3D homogeneous rotation matrix about the x-axis. More...
Transform	rotation_about_y (float angle)
	Creates a 3D homogeneous rotation matrix about the x-axis. More...
Transform	rotation_about_z (float angle)
	Creates a 3D homogeneous rotation matrix about the x-axis. More...
Transform	look_at_rotation (const Vector &center, const Vector &look_at, const Vector &up_dir)
	Creates a 3D homogeneous rotation matrix that will cause an object with the specified center to look at the specified location, with the up direction as given. More...
Transform	euler_angles_to_matrix (const Vector &euler_angles, const std::string &convention="XYZ")
	Creates a 3D homogeneous rotation matrix from three euler angles using the specified convention. More...
Transform	quaternion_to_matrix (const Quaternion &quaternion)
	Creates a 3D homogeneous rotation matrix from a quaternion. More...
Transform	gl_projection (double fov_y_degrees, double aspect_ratio, double znear, double zfar)
	Creates a WebGL projection transform (i.e. More...
Transform	gl_projection (const Intrinsic &camera_matrix, int width, int height, double znear, double zfar)
	Creates a WebGL projection transform (i.e. More...
Transform	gl_world_to_camera (const Extrinsic &extrinsic)
	Creates a WebGL view transform (i.e. More...

Function Documentation

axis_angle_to_align_x_to_axis()

std::pair< Vector, float > scenepic::Transforms::axis_angle_to_align_x_to_axis

(

const Vector &

axis

)

Find the axis and angle of rotation that will ensure the x-axis aligns with the provided axis.

NB one degree of freedom is underconstrained.

Parameters

axis	the axis to which to align the x-axis

Returns

a 3D homogeneous transform matrix

euler_angles_to_matrix()

Transform scenepic::Transforms::euler_angles_to_matrix	(	const Vector &	euler_angles,
		const std::string &	convention = "XYZ"
	)

Creates a 3D homogeneous rotation matrix from three euler angles using the specified convention.

See https://en.wikipedia.org/wiki/Euler_angles for more information on valid conventions. Conventions are specified as a three character string indicating the convention order, with values taken from [X, Y, Z].

Parameters

euler_angles	the Euler angles to use in constructing the matrix
convention	the convention to use in interpreting the angles

Returns

a 3D homogeneous transform matrix

gl_projection() [1/2]

Transform scenepic::Transforms::gl_projection	(	const Intrinsic &	camera_matrix,
		int	width,
		int	height,
		double	znear,
		double	zfar
	)

Creates a WebGL projection transform (i.e.

that goes from view coordinates to NDC) from an OpenCV-style camera matrix.

Parameters

camera_matrix	the OpenCV-style camera matrix
width	the width of the calibration image in pixels
height	the height of the calibration image in pixels
znear	the z value of the near clipping plane of the frustum
zfar	the z value of the far clipping plane of the frustum

Returns

a WebGL projection matrix

gl_projection() [2/2]

Transform scenepic::Transforms::gl_projection	(	double	fov_y_degrees,
		double	aspect_ratio,
		double	znear,
		double	zfar
	)

Creates a WebGL projection transform (i.e.

that goes from view coordinates to NDC).

Parameters

fov_y_degrees	the field of view of the camera in degrees
aspect_ratio	the aspect ratio of the camera
znear	the z value of the near clipping plane of the frustum
zfar	the z value of the far clipping plane of the frustum

Returns

a WebGL projection matrix

gl_world_to_camera()

Transform scenepic::Transforms::gl_world_to_camera

(

const Extrinsic &

extrinsic

)

Creates a WebGL view transform (i.e.

that goes from world coordinates to camera view coordinates) from an OpenCV-style extrinsic matrix

Parameters

extrinsic

the camera-to-world matrix, which places the camera in the scene

Returns

a WebGL view matrix

look_at_rotation()

Transform scenepic::Transforms::look_at_rotation	(	const Vector &	center,
		const Vector &	look_at,
		const Vector &	up_dir
	)

Creates a 3D homogeneous rotation matrix that will cause an object with the specified center to look at the specified location, with the up direction as given.

Parameters

center	the center of the object
look_at	the position to look at
up_dir	the direction that is "up"

Returns

a 3D homogeneous transform matrix

quaternion_from_axis_angle()

Quaternion scenepic::Transforms::quaternion_from_axis_angle	(	const Vector &	axis,
		float	angle
	)

Convert rotation axis and angle to a quaternion.

Parameters

axis	the axis of rotation
angle	the angle to rotate in radians

Returns

a quaternion

quaternion_multiply()

Quaternion scenepic::Transforms::quaternion_multiply	(	const Quaternion &	a,
		const Quaternion &	b
	)

Multiply two quaternions.

Parameters

a	the first quaternion
b	the second quaternion

Returns

the result of a * b

quaternion_to_align_x_to_axis()

Quaternion scenepic::Transforms::quaternion_to_align_x_to_axis

(

const Vector &

axis

)

Creates a quaternion rotation vector that will ensure the x-axis aligns with the provided axis.

NB one degree of freedom is underconstrained.

Parameters

axis	the axis to which to align the x-axis

Returns

a quaternion

quaternion_to_matrix()

Transform scenepic::Transforms::quaternion_to_matrix

(

const Quaternion &

quaternion

)

Creates a 3D homogeneous rotation matrix from a quaternion.

Parameters

quaternion

the quaternion to convert

Returns

a 3D homogeneous transform matrix.

rotation_about_x()

Transform scenepic::Transforms::rotation_about_x

(

float

angle

)

Creates a 3D homogeneous rotation matrix about the x-axis.

Parameters

angle

the angle to rotate in radians

Returns

a 3D homogeneous transform matrix

rotation_about_y()

Transform scenepic::Transforms::rotation_about_y

(

float

angle

)

Creates a 3D homogeneous rotation matrix about the x-axis.

Parameters

angle

the angle to rotate in radians

Returns

a 3D homogeneous transform matrix

rotation_about_z()

Transform scenepic::Transforms::rotation_about_z

(

float

angle

)

Creates a 3D homogeneous rotation matrix about the x-axis.

Parameters

angle

the angle to rotate in radians

Returns

a 3D homogeneous transform matrix

rotation_matrix_from_axis_angle()

Transform scenepic::Transforms::rotation_matrix_from_axis_angle	(	const Vector &	axis,
		float	angle
	)

Creates a 3D homogeneous scale matrix from axis and angle.

Parameters

axis	the axis of rotation
angle	the angle to rotate in radians

Returns

a 3D homogeneous transform matrix

rotation_to_align_x_to_axis()

Transform scenepic::Transforms::rotation_to_align_x_to_axis

(

const Vector &

axis

)

Creates a 3D homogeneous rotation matrix that will ensure the x-axis aligns with the provided axis.

NB one degree of freedom is underconstrained.

Parameters

axis	the axis to which to align the x-axis

Returns

a 3D homogeneous transform matrix

scale() [1/2]

Transform scenepic::Transforms::scale

(

const Vector &

scale

)

Creates a 3D homogeneous scale matrix.

Parameters

scale

the axis-specific scale values

Returns

a 3D homogeneous transform matrix

scale() [2/2]

Transform scenepic::Transforms::scale

(

float

scale

)

Creates a 3D homogeneous scale matrix.

Parameters

scale

the scale to use across all axes

Returns

a 3D homogeneous transform matrix

translate()

Transform scenepic::Transforms::translate

(

const Vector &

vec

)

Creates a 3D homogeneous scale matrix.

Parameters

vec	the movement vector

Returns

a 3D homogeneous transform matrix