Transformation

An object which stores a 3d transformation matrix. The matrix can be built through applying a sequential series of simple transformations (rotation, translation, scaling). The resultant compound transformation can then be applied to a node set in the keyword file.

Attributes

Attribute	Type	Description
self.matrix	np.ndarray	4x4 matrix containing the three-dimensional transformation operator

Methods

init

Initialize a new Card object

class Transformation:
    def __init__(self):

transform_operator=Transformation()

inputs

None.

returns

Transformation object containing a 4x4 identity matrix.

Scale

Applies x,y,z scale factors to the transformation operator

def scale(self, sx, sy, sz):

transform_operator=Transformation()
#scale by 2 in the x-direction
transform_operator.scale(2.0,1.0,1.0)

inputs

Attribute	Type	Description
sx	float	x-direction scale factor
sy	float	y-direction scale factor
sz	float	z-direction scale factor

returns

Updates self.matrix with the appropriate scaling operators.

Translate

Applies x,y,z translation to the transformation operator.

def translate(self, tx, ty, tz):

transform_operator=Transformation()
#shift by 2 in the x-direction
transform_operator.translate(2.0,0,0)

inputs

Attribute	Type	Description
tx	float	x-direction translation
ty	float	y-direction translation
tz	float	z-direction translation

returns

Updates self.matrix with the appropriate translation operators.

Rotate

Applies a rotation about an arbitrary axis, defined by two points in xyz space, to the transformation operator.

def rotate(self, p1, p2, angle):

transform_operator=Transformation()
#rotate by 90 degrees about the x-axis
transform_operator.transform([0,0,0],[1.0,0,0],90)

inputs

Attribute	Type	Description
p1	list[float]	Point 1 for defining rotation axis
p2	list[float]	Point 2 for defining rotation axis
angle	float	Angle (in degrees) to rotate the selected nodes about the defined axis

returns

Updates self.matrix with the appropriate rotation operators.