def tangent_array(self, ts):
t_min, t_max = self.get_u_bounds()
ts[ts < t_min] = t_min
ts[ts > t_max] = t_max
vs = operations.tangent(self.curve, list(ts), normalize=False)
tangents = [t[1] for t in vs]
#print(f"ts: {ts}, vs: {tangents}")
return np.array(tangents)
curve.knotvector = utilities.generate_knot_vector(curve.degree,
len(curve.ctrlpts))
# Set evaluation delta
curve.delta = 0.01
# Evaulate curve
curve.evaluate()
# Draw the control point polygon and the evaluated curve
vis_comp = VisPlotly.VisCurve2D()
curve.vis = vis_comp
curve.render()
# Evaluate curve tangent at u = 0.0
curvetan1 = operations.tangent(curve, 0.0, normalize=True)
# Evaluate curve tangent at u = 0.2
curvetan2 = operations.tangent(curve, 0.2, normalize=True)
# Evaluate curve tangent at u = 0.5
curvetan3 = operations.tangent(curve, 0.5, normalize=True)
# Evaluate curve tangent at u = 0.6
curvetan4 = operations.tangent(curve, 0.6, normalize=True)
# Evaluate curve tangent at u = 0.8
curvetan5 = operations.tangent(curve, 0.8, normalize=True)
# Evaluate curve tangent at u = 1.0
curvetan6 = operations.tangent(curve, 1.0, normalize=True)
def tangent(self, t):
p, t = operations.tangent(self.curve, t, normalize=False)
return np.array(t)
curve.ctrlpts = exchange.import_txt("ex_curve02.cpt")
# Auto-generate knot vector
curve.knotvector = utilities.generate_knot_vector(curve.degree, len(curve.ctrlpts))
# Set evaluation delta
curve.delta = 0.01
# Evaluate curve
curve.evaluate()
# Plot the control point polygon and the evaluated curve
vis_comp = VisMPL.VisCurve2D()
curve.vis = vis_comp
curve.render()
# Evaluate derivatives at u = 0.6
ders1 = curve.derivatives(0.6, 4)
# Change evaluator
curve.evaluator = evaluators.CurveEvaluator2()
# Evaluate derivatives at u = 0.6 using the new evaluator
ders2 = curve.derivatives(0.6, 4)
# Compute curve tangent at u = 0.6
curvetan = operations.tangent(curve, 0.6)
# Good to have something here to put a breakpoint
pass
# Set evaluation delta curve.delta = 0.01 # Evaulate curve curve.evaluate() # # Tangent Vector Evaluation # # Store tangent vectors in a list for plotting curvetan = [] # Evaluate curve tangent at u = 0.0 ct1 = operations.tangent(curve, 0.0, normalize=True) curvetan.append(ct1) # Evaluate curve tangent at u = 0.2 ct2 = operations.tangent(curve, 0.2, normalize=True) curvetan.append(ct2) # Evaluate curve tangent at u = 0.5 ct3 = operations.tangent(curve, 0.5, normalize=True) curvetan.append(ct3) # Evaluate curve tangent at u = 0.6 ct4 = operations.tangent(curve, 0.6, normalize=True) curvetan.append(ct4) # Evaluate curve tangent at u = 0.8
# Set degrees
surf.degree_u = 3
surf.degree_v = 3
# Set control points
surf.set_ctrlpts(
*exchange.import_txt("ex_surface02.cpt", two_dimensional=True))
# Set knot vectors
surf.knotvector_u = utilities.generate_knot_vector(surf.degree_u, 6)
surf.knotvector_v = utilities.generate_knot_vector(surf.degree_v, 6)
# Set evaluation delta
surf.delta = 0.025
# Evaluate surface
surf.evaluate()
# Plot the control point grid and the evaluated surface
vis_comp = VisPlotly.VisSurface()
surf.vis = vis_comp
surf.render()
# Evaluate surface tangent and normal at the given u and v
uv = [0.2, 0.9]
surf_tangent = operations.tangent(surf, uv)
surf_normal = operations.normal(surf, uv)
# Good to have something here to put a breakpoint
pass
surf.knotvector_u = utilities.generate_knot_vector(surf.degree_u, 6)
surf.knotvector_v = utilities.generate_knot_vector(surf.degree_v, 6)
# Set evaluation delta
surf.delta = 0.05
# Evaluate surface
surf.evaluate()
# Evaluate surface tangent and normal vectors
uv_vals = [[0.1, 0.1], [0.65, 0.25], [0.9, 0.7], [0.2, 0.9]]
surftans = [[] for _ in range(len(uv_vals))]
surfnorms = [[] for _ in range(len(uv_vals))]
for idx, uv in enumerate(uv_vals):
surftans[idx] = operations.tangent(surf, uv, normalize=True)
surfnorms[idx] = operations.normal(surf, uv, normalize=True)
# Prepare points for plotting
surfpts = np.array(surf.evalpts)
tangent_vectors = np.array(surftans)
normal_vectors = np.array(surfnorms)
# Start plotting of the surface and the control points grid
fig = plt.figure(figsize=(10.67, 8), dpi=96)
ax = Axes3D(fig)
# Plot surface points
ax.plot_trisurf(surfpts[:, 0],
surfpts[:, 1],
surfpts[:, 2],
# Create a B-Spline curve instance
curve = BSpline.Curve()
# Set up curve
curve.degree = 4
curve.ctrlpts = exchange.import_txt("ex_curve3d01.cpt")
# Auto-generate knot vector
curve.knotvector = utilities.generate_knot_vector(curve.degree,
len(curve.ctrlpts))
# Split the curve
split_curves = operations.split_curve(curve, 0.3)
curves = multi.CurveContainer(split_curves)
# Move the 1st curve a little bit far away from the 2nd curve
c2tan = operations.tangent(curves[1], 0.0, normalize=True)
c2tanvec = [-1 * p for p in c2tan[1]]
operations.translate(curves[0], c2tanvec, inplace=True)
# Plot the curves using the curve container
curves.sample_size = 100
# Plot the control point polygon and the evaluated curve
vis_comp = VisPlotly.VisCurve3D()
curves.vis = vis_comp
curves.render()
# Good to have something here to put a breakpoint
pass
# Set evaluation delta curve.delta = 0.001 # Evaulate curve curve.evaluate() # # Tangent Vector Evaluation # # Store tangent vectors in a list for plotting curvetan = [] # Evaluate curve tangent at u = 0.0175 ct1 = operations.tangent(curve, 0.0175, normalize=True) curvetan.append(ct1) # Evaluate curve tangent at u = 0.075 ct2 = operations.tangent(curve, 0.075, normalize=True) curvetan.append(ct2) # Evaluate curve tangent at u = 0.375 ct3 = operations.tangent(curve, 0.375, normalize=True) curvetan.append(ct3) # Evaluate curve tangent at u = 0.535 ct4 = operations.tangent(curve, 0.535, normalize=True) curvetan.append(ct4) # Evaluate curve tangent at u = 0.65
# Evaulate curve
curve.evaluate()
#
# Multiple vector evaluation after v3.0.7
#
# List of parametric coordinates to be evaluated
u_list = (0.0175, 0.075, 0.375, 0.535, 0.65, 0.85, 0.975)
# Evaluate tangents, normals and binormals, respectively
curvetans = [[] for _ in range(len(u_list))]
curvenorms = [[] for _ in range(len(u_list))]
curvebinorms = [[] for _ in range(len(u_list))]
for idx, u in enumerate(u_list):
curvetans[idx] = operations.tangent(curve, u, normalize=True)
curvenorms[idx] = operations.normal(curve, u, normalize=True)
curvebinorms[idx] = operations.binormal(curve, u, normalize=True)
#
# Control Points, Curve and Tangent Vector Plotting using Matplotlib
#
# Arrange control points and evaluated curve points for plotting
ctrlpts = np.array(curve.ctrlpts)
curvepts = np.array(curve.evalpts)
# Convert tangent, normal and binormal vector lists into NumPy arrays
ctarr = np.array(curvetans)
cnarr = np.array(curvenorms)
cbnarr = np.array(curvebinorms)
