NURBS-Python comes with the following visualization modules for direct plotting evaluated curves and surfaces:
- :doc:`VisMPL <module_vis_mpl>` module for Matplotlib
- :doc:`VisPlotly <module_vis_plotly>` module for Plotly
- :doc:`VisVTK <module_vis_vtk>` module for VTK
Examples repository contains over 40 examples on how to use the visualization components in various ways. Please see :doc:`Visualization Modules Documentation <modules_visualization>` for more details.
The following figures illustrate some example NURBS and B-spline shapes that can be generated and directly visualized via NURBS-Python.
.. plot::
from geomdl import BSpline
from geomdl import utilities
from geomdl.visualization import VisMPL
# Create a B-Spline curve
curve = BSpline.Curve()
# Set up the curve
curve.degree = 4
curve.ctrlpts = [[5.0, 10.0], [15.0, 25.0], [30.0, 30.0], [45.0, 5.0], [55.0, 5.0], [70.0, 40.0], [60.0, 60.0], [35.0, 60.0], [20.0, 40.0]]
# Auto-generate knot vector
curve.knotvector = utilities.generate_knot_vector(curve.degree, len(curve.ctrlpts))
# Set evaluation delta
curve.delta = 0.01
# Plot the control point polygon and the evaluated curve
curve.vis = VisMPL.VisCurve2D()
curve.render()
.. plot::
from geomdl import BSpline
from geomdl import utilities
from geomdl.visualization import VisMPL
ctrlpts = [[5.0, 5.0, 0.0], [5.0, 10.0, 0.0], [10.0, 10.0, 5.0], [10.0, 5.0, 5.0], [5.0, 5.0, 5.0], [5.0, 10.0, 10.0], [10.0, 10.0, 10.0], [10.0, 5.0, 10.0], [5.0, 5.0, 15.0], [5.0, 10.0, 15.0], [10.0, 10.0, 15.0], [10.0, 5.0, 20.0], [5.0, 5.0, 20.0]]
# Create a B-Spline curve instance
curve = BSpline.Curve()
# Set up curve
curve.degree = 3
curve.ctrlpts = ctrlpts
# Auto-generate knot vector
curve.knotvector = utilities.generate_knot_vector(curve.degree, curve.ctrlpts_size)
# Set evaluation delta
curve.delta = 0.01
# Plot the control point polygon and the evaluated curve
curve.vis = VisMPL.VisCurve3D()
curve.render()
.. plot::
from geomdl import BSpline
from geomdl.visualization import VisMPL
# Control points
ctrlpts = [
[[-25.0, -25.0, -10.0], [-25.0, -15.0, -5.0], [-25.0, -5.0, 0.0], [-25.0, 5.0, 0.0], [-25.0, 15.0, -5.0], [-25.0, 25.0, -10.0]],
[[-15.0, -25.0, -8.0], [-15.0, -15.0, -4.0], [-15.0, -5.0, -4.0], [-15.0, 5.0, -4.0], [-15.0, 15.0, -4.0], [-15.0, 25.0, -8.0]],
[[-5.0, -25.0, -5.0], [-5.0, -15.0, -3.0], [-5.0, -5.0, -8.0], [-5.0, 5.0, -8.0], [-5.0, 15.0, -3.0], [-5.0, 25.0, -5.0]],
[[5.0, -25.0, -3.0], [5.0, -15.0, -2.0], [5.0, -5.0, -8.0], [5.0, 5.0, -8.0], [5.0, 15.0, -2.0], [5.0, 25.0, -3.0]],
[[15.0, -25.0, -8.0], [15.0, -15.0, -4.0], [15.0, -5.0, -4.0], [15.0, 5.0, -4.0], [15.0, 15.0, -4.0], [15.0, 25.0, -8.0]],
[[25.0, -25.0, -10.0], [25.0, -15.0, -5.0], [25.0, -5.0, 2.0], [25.0, 5.0, 2.0], [25.0, 15.0, -5.0], [25.0, 25.0, -10.0]]
]
# Create a BSpline surface
surf = BSpline.Surface()
# Set degrees
surf.degree_u = 3
surf.degree_v = 3
# Set control points
surf.ctrlpts2d = ctrlpts
# Set knot vectors
surf.knotvector_u = [0.0, 0.0, 0.0, 0.0, 1.0, 2.0, 3.0, 3.0, 3.0, 3.0]
surf.knotvector_v = [0.0, 0.0, 0.0, 0.0, 1.0, 2.0, 3.0, 3.0, 3.0, 3.0]
# Set evaluation delta
surf.delta = 0.025
# Evaluate surface points
surf.evaluate()
# Import and use Matplotlib's colormaps
from matplotlib import cm
# Plot the control points grid and the evaluated surface
surf.vis = VisMPL.VisSurface()
surf.render(colormap=cm.cool)
.. plot::
from geomdl import NURBS
from geomdl.visualization import VisMPL
ctrlpts = [
[[1.0, 0.0, 0.0, 1.0], [0.7071, 0.7071, 0.0, 0.7071], [0.0, 1.0, 0.0, 1.0], [-0.7071, 0.7071, 0.0, 0.7071], [-1.0, 0.0, 0.0, 1.0], [-0.7071, -0.7071, 0.0, 0.7071], [0.0, -1.0, 0.0, 1.0], [0.7071, -0.7071, 0.0, 0.7071], [1.0, 0.0, 0.0, 1.0]],
[[1.0, 0.0, 1.0, 1.0], [0.7071, 0.7071, 0.7071, 0.7071], [0.0, 1.0, 1.0, 1.0], [-0.7071, 0.7071, 0.7071, 0.7071], [-1.0, 0.0, 1.0, 1.0], [-0.7071, -0.7071, 0.7071, 0.7071], [0.0, -1.0, 1.0, 1.0], [0.7071, -0.7071, 0.7071, 0.7071], [1.0, 0.0, 1.0, 1.0]]
]
# Create a NURBS surface
surf = NURBS.Surface()
# Set degrees
surf.degree_u = 1
surf.degree_v = 2
# Set control points
surf.ctrlpts2d = ctrlpts
# Set knot vectors
surf.knotvector_u = [0, 0, 1, 1]
surf.knotvector_v = [0, 0, 0, 0.25, 0.25, 0.5, 0.5, 0.75, 0.75, 1, 1, 1]
# Set evaluation delta
surf.delta = 0.05
# Plot the control point grid and the evaluated surface
surf.vis = VisMPL.VisSurface()
surf.render()
.. plot::
from geomdl import BSpline
from geomdl import CPGen
from geomdl import multi
from geomdl import utilities
from geomdl import construct
from geomdl.visualization import VisMPL
# Generate control points grid for Surface #1
sg01 = CPGen.Grid(15, 10, z_value=0.0)
sg01.generate(8, 8)
# Create a BSpline surface instance
surf01 = BSpline.Surface()
# Set degrees
surf01.degree_u = 1
surf01.degree_v = 1
# Get the control points from the generated grid
surf01.ctrlpts2d = sg01.grid
# Set knot vectors
surf01.knotvector_u = utilities.generate_knot_vector(surf01.degree_u, surf01.ctrlpts_size_u)
surf01.knotvector_v = utilities.generate_knot_vector(surf01.degree_v, surf01.ctrlpts_size_v)
# Generate control points grid for Surface #2
sg02 = CPGen.Grid(15, 10, z_value=1.0)
sg02.generate(8, 8)
# Create a BSpline surface instance
surf02 = BSpline.Surface()
# Set degrees
surf02.degree_u = 1
surf02.degree_v = 1
# Get the control points from the generated grid
surf02.ctrlpts2d = sg02.grid
# Set knot vectors
surf02.knotvector_u = utilities.generate_knot_vector(surf02.degree_u, surf02.ctrlpts_size_u)
surf02.knotvector_v = utilities.generate_knot_vector(surf02.degree_v, surf02.ctrlpts_size_v)
# Generate control points grid for Surface #3
sg03 = CPGen.Grid(15, 10, z_value=2.0)
sg03.generate(8, 8)
# Create a BSpline surface instance
surf03 = BSpline.Surface()
# Set degrees
surf03.degree_u = 1
surf03.degree_v = 1
# Get the control points from the generated grid
surf03.ctrlpts2d = sg03.grid
# Set knot vectors
surf03.knotvector_u = utilities.generate_knot_vector(surf03.degree_u, surf03.ctrlpts_size_u)
surf03.knotvector_v = utilities.generate_knot_vector(surf03.degree_v, surf03.ctrlpts_size_v)
# Construct the parametric volume
pvolume = construct.construct_volume('w', surf01, surf02, surf03, degree=1)
# Construct the isosurface
surfiso = construct.extract_isosurface(pvolume)
msurf = multi.SurfaceContainer(surfiso)
# Render the isourface
msurf.vis = VisMPL.VisSurface(VisMPL.VisConfig(ctrlpts=False, legend=False))
msurf.delta = 0.05
msurf.render(evalcolor=["skyblue", "cadetblue", "crimson", "crimson", "crimson", "crimson"])
The following example scripts can be found in Examples repository under the visualization directory.
This example illustrates a more advanced visualization option for plotting the 2D curve tangents alongside with the control points grid and the evaluated curve.
This example illustrates a more advanced visualization option for plotting the 3D curve tangents alongside with the control points grid and the evaluated curve.
This example illustrates a visualization option for plotting the 3D curve tangent, normal and binormal vectors alongside with the control points grid and the evaluated curve.
The following figure illustrates tangent and normal vectors on ex_surface02.py example.
