NURBS-Python
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Published
20 hours ago •
orbingol
orbingol
Help wanted: unknown ZeroDivisionError
this is my code
from geomdl import BSpline
# Create a BSpline surface instance (Bezier surface)
surf = BSpline.Surface()
surf.degree_u=2
surf.degree_v=2
surf.ctrlpts_size_u=5
surf.ctrlpts_size_v=9
surf.ctrlpts=[
(52.5, 60, 0),
(52.5, 60, 60),
(52.5, 0, 60),
(52.5, -59.999999999999986, 60.000000000000007),
(52.5, -60, 0),
(52.5, -60.000000000000007, -59.999999999999986),
(52.5, 0, -60),
(52.5, 60, -60.000000000000021),
(52.5, 60, 0),
(17.500000000000004, 59.999999999999986, 0),
(17.5, 59.999999999999986, 59.999999999999986),
(17.500000000000004, 0, 59.999999999999986),
(17.5, -59.999999999999979, 59.999999999999993),
(17.500000000000004, -59.999999999999986, 0),
(17.5, -59.999999999999993, -59.999999999999979),
(17.500000000000004, 0, -59.999999999999986),
(17.5, 59.999999999999986, -60),
(17.500000000000004, 59.999999999999986, 0),
(17.5, 0, 0),
(17.5, 0, 0),
(17.5, 0, 0),
(17.5, 0, 0),
(17.5, 0, 0),
(17.5, 0, 0),
(17.5, 0, 0),
(17.5, 0, 0),
(17.5, 0, 0),
(0, 0, 0),
(0, 0, 0),
(0, 0, 0),
(0, 0, 0),
(0, 0, 0),
(0, 0, 0),
(0, 0, 0),
(0, 0, 0),
(0, 0, 0),
(0, 0, 0),
(0, 0, 0),
(0, 0, 0),
(0, 0, 0),
(0, 0, 0),
(0, 0, 0),
(0, 0, 0),
(0, 0, 0),
(0, 0, 0),
]
surf.weights=[
1, 0.707107, 1, 0.707107, 1, 0.707107, 1, 0.707107, 1, 0.707107, 0.5, 0.707107, 0.5, 0.707107, 0.5, 0.707107, 0.5, 0.707107, 1, 0.707107, 1, 0.707107, 1, 0.707107, 1, 0.707107, 1, 6.95192e-310, 52.5, 60, 0, 52.5, 60, 60, 52.5, 3.67e-15, 60, 52.5, -60, 60, 52.5, -60, 7.35e-15, 52.5, -60, ]
surf.knotvector_u=[0, 0, 0, 1, 1, 1, 1, 1, ]
surf.knotvector_v=[0, 0, 0, 0.25, 0.25, 0.5, 0.5, 0.75, 0.75, 1, 1, 1, ]
# Evaluate surface points
surf.evaluate()
and I get below error
ZeroDivisionError Traceback (most recent call last)
Input In [83], in <cell line: 1>()
60 surf.knotvector_v=[0, 0, 0, 0.25, 0.25, 0.5, 0.5, 0.75, 0.75, 1, 1, 1, ]
61 # Evaluate surface points
---> 62 surf.evaluate()
64 # Plot the control points grid and the evaluated surface
65 surf.vis = VisMPL.VisSurface(vis_config)
File ~/anaconda3/lib/python3.9/site-packages/geomdl/BSpline.py:616, in Surface.evaluate(self, **kwargs)
613 self.reset(evalpts=True)
615 # Evaluate and cache
--> 616 self._eval_points = self._evaluator.evaluate(self.data,
617 start=(start_u, start_v),
618 stop=(stop_u, stop_v))
File ~/anaconda3/lib/python3.9/site-packages/geomdl/evaluators.py:291, in SurfaceEvaluator.evaluate(self, datadict, **kwargs)
289 knots = linalg.linspace(start[idx], stop[idx], sample_size[idx], decimals=precision)
290 spans[idx] = helpers.find_spans(degree[idx], knotvector[idx], size[idx], knots, self._span_func)
--> 291 basis[idx] = helpers.basis_functions(degree[idx], knotvector[idx], spans[idx], knots)
293 eval_points = []
294 for i in range(len(spans[0])):
File ~/anaconda3/lib/python3.9/site-packages/geomdl/helpers.py:250, in basis_functions(degree, knot_vector, spans, knots)
248 basis = []
249 for span, knot in zip(spans, knots):
--> 250 basis.append(basis_function(degree, knot_vector, span, knot))
251 return basis
File ~/anaconda3/lib/python3.9/site-packages/geomdl/helpers.py:167, in basis_function(degree, knot_vector, span, knot)
165 saved = 0.0
166 for r in range(0, j):
--> 167 temp = N[r] / (right[r + 1] + left[j - r])
168 N[r] = saved + right[r + 1] * temp
169 saved = left[j - r] * temp
ZeroDivisionError: float division by zero
The equivalent ACIS code
// spline
int degree_of_u = 2;
logical is_rational_in_u = TRUE;
int OPEN = 0;
int form_u = OPEN;
int NO_SINGULARITY_AT_U_BOUNDARY = 0;
int pole_u = NO_SINGULARITY_AT_U_BOUNDARY;
int control_points_in_u = 5;
int degree_v = 2;
logical is_rational_in_v = TRUE;
int form_v = 2;
int pole_v = NO_SINGULARITY_AT_U_BOUNDARY;
int control_points_in_v = 9;
SPAposition control_points[] = {
{52.50000000000000000, 60.00000000000000000, 0.00000000000000000 },
{52.50000000000000000, 60.00000000000000000, 60.00000000000000000 },
{52.50000000000000000, 0.00000000000000367, 60.00000000000000000 },
{52.50000000000000000, -59.99999999999998579, 60.00000000000000711 },
{52.50000000000000000, -60.00000000000000000, 0.00000000000000735 },
{52.50000000000000000, -60.00000000000000711, -59.99999999999998579},
{52.50000000000000000, -0.00000000000001102, -60.00000000000000000},
{52.50000000000000000, 60.00000000000000000, -60.00000000000002132},
{52.50000000000000000, 60.00000000000000000, 0.00000000000000000 },
{17.50000000000000355, 59.99999999999998579, 0.00000000000000000 },
{17.50000000000000000, 59.99999999999998579, 59.99999999999998579 },
{17.50000000000000355, 0.00000000000000367, 59.99999999999998579 },
{17.50000000000000000, -59.99999999999997868, 59.99999999999999289 },
{17.50000000000000355, -59.99999999999998579, 0.00000000000000735 },
{17.50000000000000000, -59.99999999999999289, -59.99999999999997868},
{17.50000000000000355, -0.00000000000001102, -59.99999999999998579},
{17.50000000000000000, 59.99999999999998579, -60.00000000000000000},
{17.50000000000000355, 59.99999999999998579, 0.00000000000000000 },
{17.50000000000000000, 0.00000000000000000, 0.00000000000000000 },
{17.50000000000000000, 0.00000000000000000, 0.00000000000000000 },
{17.50000000000000000, 0.00000000000000000, 0.00000000000000000 },
{17.50000000000000000, 0.00000000000000000, 0.00000000000000000 },
{17.50000000000000000, 0.00000000000000000, 0.00000000000000000 },
{17.50000000000000000, 0.00000000000000000, 0.00000000000000000 },
{17.50000000000000000, 0.00000000000000000, 0.00000000000000000 },
{17.50000000000000000, 0.00000000000000000, 0.00000000000000000 },
{17.50000000000000000, 0.00000000000000000, 0.00000000000000000 },
};
double weights[] = {
1.00000000000000000, 0.70710678118654757, 1.00000000000000000, 0.70710678118654757, 1.00000000000000000, 0.70710678118654757, 1.00000000000000000, 0.70710678118654757, 1.00000000000000000,
0.70710678118654779, 0.50000000000000022, 0.70710678118654779, 0.50000000000000022, 0.70710678118654779, 0.50000000000000022, 0.70710678118654779, 0.50000000000000022, 0.70710678118654779,
1.00000000000000000, 0.70710678118654757, 1.00000000000000000, 0.70710678118654757, 1.00000000000000000, 0.70710678118654757, 1.00000000000000000, 0.70710678118654757, 1.00000000000000000,
};
double control_points_tolerance = SPAresabs;
int num_knots_u = 6;
double knots_u[] = {
0.00000000000000000, 0.00000000000000000, 0.00000000000000000, 1.00000000000000000, 1.00000000000000000, 1.00000000000000000,
};
int num_knots_v = 12;
double knots_v[] = {
0.00000000000000000, 0.00000000000000000, 0.00000000000000000, 0.25000000000000000, 0.25000000000000000, 0.50000000000000000,
0.50000000000000000, 0.75000000000000000, 0.75000000000000000, 1.00000000000000000, 1.00000000000000000, 1.00000000000000000,
};
double knot_tol = SPAresabs;
//
bs3_surface bezier_surface = bs3_surface_from_ctrlpts(degree_of_u, is_rational_in_u, form_u, pole_u, control_points_in_u, degree_v, is_rational_in_v, form_v, pole_v, control_points_in_v, control_points, weights, control_points_tolerance, num_knots_u,
knots_u, num_knots_v, knots_v, knot_tol);
spline spl = spline(bezier_surface);
Could you please take a look at this bug ? I would greatly appreciate your assistance. Thank you in advance!
