psychopy.tools.mathtools.RigidBodyPose

class psychopy.tools.mathtools.RigidBodyPose(pos=(0.0, 0.0, 0.0), ori=(0.0, 0.0, 0.0, 1.0), dtype=None)

Class for representing rigid body poses.

This class is an abstract representation of a rigid body pose, where the position of the body in a scene is represented by a vector/coordinate and the orientation with a quaternion. Pose can be manipulated and interacted with using class methods and attributes. Rigid body poses assume a right-handed coordinate system (-Z is forward and +Y is up).

Poses can be converted to 4x4 transformation matrices with getModelMatrix. One can use these matrices when rendering to transform the vertices of a model associated with the pose by passing them to OpenGL. Matrices are cached internally to avoid recomputing them if pos and ori attributes have not been updated.

Operators * and ~ can be used on RigidBodyPose objects to combine and invert poses. For instance, you can multiply (*) poses to get a new pose which is the combination of both orientations and translations by:

newPose = rb1 * rb2

Likewise, a pose can be inverted by using the ~ operator:

invPose = ~rb

Multiplying a pose by its inverse will result in an identity pose with no translation and default orientation where pos=[0, 0, 0] and ori=[0, 0, 0, 1]:

identityPose = ~rb * rb

Warning

This class is experimental and may result in undefined behavior.

Parameters:

• pos (array_like) – Position vector [x, y, z] for the origin of the rigid body.

• ori (array_like) – Orientation quaternion [x, y, z, w] where x, y, z are imaginary and w is real.

• dtype (dtype or str, optional) – Data type for computations can either be ‘float32’ or ‘float64’. Default is None which uses the default data configured by setDefaultPrecision.

__init__(pos=(0.0, 0.0, 0.0), ori=(0.0, 0.0, 0.0, 1.0), dtype=None)

Parameters:

• pos (array_like) – Position vector [x, y, z] for the origin of the rigid body.

• ori (array_like) – Orientation quaternion [x, y, z, w] where x, y, z are imaginary and w is real.

• dtype (dtype or str, optional) – Data type for computations can either be ‘float32’ or ‘float64’. Default is None which uses the default data configured by setDefaultPrecision.

Methods

__init__([pos, ori, dtype])
alignTo(alignTo)	Align this pose to another point or pose.
clear()	Clear the pose, setting position and orientation to zero.
copy()	Get a new RigidBodyPose object which copies the position and orientation of this one.
distanceTo(v)	Get the distance to a pose or point in scene units.
getModelMatrix([inverse, out])	Get the present rigid body transformation as a 4x4 matrix.
getNormalMatrix([out])	Get the present normal matrix.
getOriAxisAngle([degrees])	Get the axis and angle of rotation for the rigid body.
getViewMatrix([inverse, out])	Convert this pose into a view matrix.
getYawPitchRoll([degrees])	Get the yaw, pitch and roll angles for this pose relative to the -Z world axis.
interp(end, s)	Interpolate between poses.
invert()	Invert this pose.
inverted()	Get a pose which is the inverse of this one.
isEqual(other)	Check if poses have similar orientation and position.
setIdentity()	Clear rigid body transformations (alias for clear).
setOriAxisAngle(axis, angle[, degrees])	Set the orientation of the rigid body using an axis and angle.
transform(v[, out])	Transform a vector using this pose.
transformNormal(n)	Rotate a normal vector with respect to this pose.

Attributes

at	Vector defining the forward direction (-Z) of this pose.
bounds	Bounding box associated with this pose.
dtype	Data type used for computations and arrays (numpy.dtype).
inverseModelMatrix	Inverse of the pose as a 4x4 model matrix (read-only).
inverseViewMatrix	The inverse of the 4x4 view matrix for this pose (read-only).
modelMatrix	Pose as a 4x4 model matrix (read-only).
normalMatrix	The 4x4 normal transformation matrix (read-only).
ori	Orientation quaternion (X, Y, Z, W).
pos	Position vector (X, Y, Z).
posOri	The position (x, y, z) and orientation (x, y, z, w).
up	Vector defining the up direction (+Y) of this pose.
viewMatrix	The 4x4 view matrix for this pose (read-only).

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