CompatibilityΒΆ
Most of the time, users experience problems in converting data between different software packages. To aid this problem a little bit, NURBS-Python provides a compatibility module for converting control points sets into NURBS-Python compatible ones.
The following example illustrates the usage of compatibility module:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 | from geomdl import NURBS
from geomdl import utilities as utils
from geomdl import compatibility as compat
from geomdl.visualization import VisMPL
#
# Surface exported from your CAD software
#
# Dimensions of the control points grid
p_size_u = 4
p_size_v = 3
# Control points in u-row order
p_ctrlpts = [[0, 0, 0], [1, 0, 6], [2, 0, 0], [3, 0, 0],
[0, 1, 0], [1, 1, 0], [2, 1, 0], [3, 1, -3],
[0, 2, -3], [1, 2, 0], [2, 2, 3], [3, 2, 0]]
# Weights vector
p_weights = [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1]
# Degrees
p_degree_u = 3
p_degree_v = 2
#
# Prepare data for import
#
# Combine weights vector with the control points list
t_ctrlptsw = compat.combine_ctrlpts_weights(p_ctrlpts, p_weights)
# Since NURBS-Python uses v-row order, we need to convert the exported ones
n_ctrlptsw = compat.flip_ctrlpts_u(t_ctrlptsw, p_size_u, p_size_v)
# Since we have no information on knot vectors, let's auto-generate them
n_knotvector_u = utils.generate_knot_vector(p_degree_u, p_size_u)
n_knotvector_v = utils.generate_knot_vector(p_degree_v, p_size_v)
#
# Import surface to NURBS-Python
#
# Create a NURBS surface instance
surf = NURBS.Surface()
# Fill the surface object
surf.degree_u = p_degree_u
surf.degree_v = p_degree_v
surf_set_ctrlpts(n_ctrlptsw, p_size_u, p_size_v)
surf.knotvector_u = n_knotvector_u
surf.knotvector_v = n_knotvector_v
# Set evaluation delta
surf.delta = 0.05
# Set visualization component
vis_comp = VisMPL.VisSurface()
surf.vis = vis_comp
# Render the surface
surf.render()
|
Please see Compatibility Module Documentation for more details on manipulating and exporting control points.
NURBS-Python has some other options for exporting and importing data. Please see File Formats page for details.