Released under MIT License
Developed by Onur Rauf Bingol (c) 2016-2017
"""
from nurbs import Curve as ns
from nurbs import utilities as utils
from matplotlib import pyplot as plt
# Create a NURBS curve instance
curve = ns.Curve()
# Set up the NURBS curve
curve.read_ctrlpts("data\CP_Curve3.txt")
curve.degree = 3
# Auto-generate the knot vector
curve.knotvector = utils.knotvector_autogen(curve.degree, len(curve.ctrlpts))
# Evaulate curve
curve.evaluate()
# Arrange curve points for plotting
curvepts_x = []
curvepts_y = []
for pt in curve.curvepts:
curvepts_x.append(pt[0])
curvepts_y.append(pt[1])
# Arrange tangents for plotting
X = []
Y = []
U = []
Developed by Onur Rauf Bingol (c) 2016-2017
"""
from nurbs import Surface as ns
from nurbs import utilities as utils
from matplotlib import pyplot as plt
from mpl_toolkits.mplot3d import Axes3D
# Create a NURBS surface instance
surf = ns.Surface()
# Set up the NURBS surface
surf.read_ctrlpts("data\CP_Surface2.txt")
surf.degree_u = 3
surf.degree_v = 3
surf.knotvector_u = utils.knotvector_autogen(surf.degree_u, 6)
surf.knotvector_v = utils.knotvector_autogen(surf.degree_v, 6)
# Evaluate surface
surf.evaluate_rational()
# Calculate 1st order surface derivative at the given u and v
u = 0.2
v = 0.9
surftan = surf.tangent(u, v)
print("* Surface point at u = %.2f and v = %.2f is (%.2f, %.2f, %.2f)" % (u, v, surftan[0][0], surftan[0][1], surftan[0][2]))
print("* First derivative w.r.t. u is (%.2f, %.2f, %.2f)" % (surftan[1][0], surftan[1][1], surftan[1][2]))
print("* First derivative w.r.t. v is (%.2f, %.2f, %.2f)\n" % (surftan[2][0], surftan[2][1], surftan[2][2]))
# Calculate normal at the given u and v
norm = surf.normal(u, v)
print("* Normal at u = %.2f and v = %.2f is [%.1f, %.1f, %.1f]\n" % (u, v, norm[0], norm[1], norm[2]))