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import numpy as np
from geometry import Mesh
from transform import rotate
def rotate_extrude(x, y, theta=np.pi/32, remove_duplicate_vertices=True):
x, y, = np.asarray(x), np.asarray(y)
if len(x.shape) != 1 or len(y.shape) != 1 or x.size != y.size:
raise ValueError('shape mismatch')
points = np.zeros((len(x),3), dtype=np.float32)
points[:,0] = x
points[:,1] = y
angles = np.arange(0, 2*np.pi, theta)
vertices = np.empty((len(points)*len(angles), 3), dtype=np.float32)
triangles = np.zeros((len(angles)*(len(points)-1)*2, 3), dtype=np.int32)
step = len(points) - 1
for i, angle in enumerate(angles):
this_slice = i*len(points)
vertices[this_slice:this_slice+len(points)] = rotate(points, angle, (0,-1,0))
start = 2*i*step
next_slice = ((i+1) % len(angles))*len(points)
triangles[start:start+step,0] = np.arange(this_slice, this_slice+len(points)-1)
triangles[start:start+step,1] = np.arange(next_slice, next_slice+len(points)-1)
triangles[start:start+step,2] = np.arange(this_slice+1, this_slice+len(points))
triangles[start+step:start+2*step,0] = np.arange(next_slice, next_slice+len(points)-1)
triangles[start+step:start+2*step,2] = np.arange(this_slice+1, this_slice+len(points))
triangles[start+step:start+2*step,1] = np.arange(next_slice+1, next_slice+len(points))
return Mesh(vertices, triangles, remove_duplicate_vertices=remove_duplicate_vertices)
def cube(size=1):
a = np.sqrt(size**2/2.0)
x = [0,a,a,0]
y = [-size/2.0,-size/2.0,size/2.0,size/2.0]
return rotate_extrude(x, y, np.pi/2)
def cylinder(radius1=1, radius2=1, height=2, theta=np.pi/32):
x = [0,radius1,radius2,0]
y = [-height/2.0, -height/2.0, height/2.0, height/2.0]
return rotate_extrude(x, y, theta)
def segmented_cylinder(radius, height=2, theta=np.pi/32, n=50):
x = np.concatenate((np.linspace(0, radius, n, endpoint=False),
[radius] * n,
np.linspace(radius, 0, n, endpoint=False),
[0.0]))
y = np.concatenate(([-height/2.0] * n,
np.linspace(-height/2.0, height/2.0, n, endpoint=False),
[height/2.0] * (n+1)))
return rotate_extrude(x, y, theta)
def sphere(radius=1, theta=np.pi/32):
profile_angles = np.arange(-np.pi/2, np.pi/2+theta, theta)
return rotate_extrude(radius*np.cos(profile_angles), radius*np.sin(profile_angles), theta)
def torus(radius=1, offset=3, phi=np.pi/32, theta=np.pi/32):
profile_angles = np.arange(0, 2*np.pi+phi, phi)
x, y = np.cos(profile_angles), np.sin(profile_angles)
return rotate_extrude(x + offset, y)
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