Source code for morse.helpers.transformation
from morse.core import blenderapi
from morse.core import mathutils
from math import sqrt
[docs]class Transformation3d:
"""
Transformation3d represents a generic 3D transformation. It is used
by each component of the simulator to know their position in the
world. Blender does not propose such an interface, only some
rotation matrix and translation vector.
Internally, we store an internal 4x4 matrix, and use it to compute
transformation. the euler representation is then calculated on base
of matrix (euler ZYX convention)
Note : Blender store its matrix in column major mode ...
"""
def __init__(self, obj):
"""
Construct a transformation3d. Generate the identify
transformation if no object is associated to it. Otherwise,
returns the transformation3D between this object and the world
reference
"""
self.matrix = mathutils.Matrix(([1, 0, 0, 0],
[0, 1, 0, 0],
[0, 0, 1, 0],
[0, 0, 0, 1]))
self.euler = mathutils.Euler([0, 0, 0])
if obj is not None:
self.update(obj)
# For use only by robots moving along the Y axis
self.correction_matrix = mathutils.Matrix(([0.0, 1.0, 0.0],
[-1.0, 0.0, 0.0],
[0.0, 0.0, 1.0]))
@property
def x(self):
"""
Return the translation along the x-axis
"""
return self.matrix[0][3]
@property
def y(self):
"""
Return the translation along the y-axis
"""
return self.matrix[1][3]
@property
def z(self):
"""
Return the translation along the z-axis
"""
return self.matrix[2][3]
@property
def yaw(self):
"""
Returns Euler Z axis, in radian
"""
return self.euler.z
@property
def pitch(self):
"""
Returns Euler Y axis, in radian
"""
return self.euler.y
@property
def roll(self):
"""
Returns Euler X axis, in radian
"""
return self.euler.x
@property
def rotation(self):
"""
Returns the rotation as a unit quaternion
"""
return self.matrix.to_quaternion()
@rotation.setter
def rotation(self, value):
rmat = value.to_matrix()
for i in range(0, 3):
self.matrix[i][0:3] = rmat[i][0:3]
self.euler = self.matrix.to_euler()
@property
def rotation_matrix(self):
"""
Returns the rotation as a 3x3 matrix
"""
return self.matrix.to_3x3()
@property
def translation(self):
return self.matrix.translation
@translation.setter
def translation(self, value):
self.matrix.translation = value
[docs] def transformation3d_with(self, t3d):
"""
Compute the transformation between itself and another
transformation t3d. In other words, A.transformation3d_with(B)
returns inv(A) * B.
self is not modified by the call of this function
"""
res = Transformation3d(None)
o2m = self.matrix.copy()
o2m.invert()
res.matrix = o2m * t3d.matrix
res.euler = res.matrix.to_euler()
return res
[docs] def distance(self, t3d):
"""
Compute the 3d distance between two transformations.
nor self, nor t3d are modified by the call of this method
"""
diff_x = self.x - t3d.x
diff_y = self.y - t3d.y
diff_z = self.z - t3d.z
return sqrt(diff_x * diff_x + diff_y * diff_y + diff_z * diff_z)
[docs] def distance_2d(self, t3d):
"""
Compute the 2d distance between two transformations.
nor self, nor t3d are modified by the call of this method
"""
diff_x = self.x - t3d.x
diff_y = self.y - t3d.y
return sqrt(diff_x * diff_x + diff_y * diff_y)
[docs] def update(self, obj):
"""
Update the transformation3D to reflect the transformation
between obj (a blender object) and the blender world origin
"""
self.matrix = obj.worldOrientation.to_4x4()
pos = obj.worldPosition
for i in range(0, 3):
self.matrix[i][3] = pos[i]
self.matrix[3][3] = 1
self.euler = self.matrix.to_euler()
[docs] def update_Y_forward(self, obj):
"""
Update the transformation3D to reflect the transformation
between obj (a blender object) and the blender world origin.
In this case, the robot moves forwar along the Y axis.
Change the values of yaw, pitch, roll for Blender vehicles
Robots that use the Blender vehicle constraints move in the
direction of the Y axis, contrary to most of the MORSE components
that move along the X axis.
"""
self.matrix = (obj.worldOrientation * self.correction_matrix).to_4x4()
pos = obj.worldPosition
for i in range(0, 3):
self.matrix[i][3] = pos[i]
self.matrix[3][3] = 1
self.euler = self.matrix.to_euler()
def __str__(self):
"""
String representation of a transformation3D
"""
res = "x : " + str(self.x)
res += " y : " + str(self.y)
res += " z : " + str(self.z)
res += " yaw : " + str(self.yaw)
res += " pitch : " + str(self.pitch)
res += " roll : " + str(self.roll)
return res