model-converter-python/d3/geometry.py

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import math
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class Vector:
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""" 3D Vector
Simple class that represents a 3D vector
"""
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def __init__(self, x = 0.0, y = 0.0, z = 0.0):
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"""
Creates a vector from it's coordinates
"""
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self.x = x
self.y = y
self.z = z
def from_array(self, arr):
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"""
Creates a vector from an array
"""
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self.x = float(arr[0]) if len(arr) > 0 else None
self.y = float(arr[1]) if len(arr) > 1 else None
self.z = float(arr[2]) if len(arr) > 2 else None
return self
def __add__(self, other):
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"""
Sums two vectors
"""
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return Vector(self.x + other.x, self.y + other.y, self.z + other.z)
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def __sub__(self, other):
"""
Subs two vectors
"""
return Vector(self.x - other.x, self.y - other.y, self.z - other.z)
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def __mul__(self, other):
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"""
Computes the product between a vector and a number
"""
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return Vector(self.x * other, self.y * other, self.z * other)
def __rmul__(self, other):
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"""
Computes the product between a vector and a number
"""
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return self.__mul__(other)
def norm2(self):
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"""
Computes the square of the norm of a vector
"""
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return self.x * self.x + self.y * self.y + self.z * self.z
def norm(self):
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"""
Compute the norm of a vector
"""
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return math.sqrt(self.norm2())
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def normalize(self):
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"""
Divides each coordinate of the vector by its norm
"""
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norm = self.norm()
if abs(norm) > 0.0001:
self.x /= norm
self.y /= norm
self.z /= norm
def cross_product(v1, v2):
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"""
Computes the cross product between the two vectors
"""
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return Vector(
v1.y * v2.z - v1.z * v2.y,
v1.z * v2.x - v1.x * v2.z,
v1.x * v2.y - v1.y * v2.x)
def from_points(v1, v2):
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"""
Creates a vector from two points
"""
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return Vector(
v2.x - v1.x,
v2.y - v1.y,
v2.z - v1.z)
def __str__(self):
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"""
Prints the coordinates of the vector between partheses
"""
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return '(' + ", ".join([str(self.x), str(self.y), str(self.z)]) + ")"
def dot(self, other):
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"""
Computes the dot product of two vectors
"""
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return self.x * other.x + self.y * other.y + self.z * other.z