for p, t in zip(data, tangents):
msp.add_line(p,
p + t,
dxfattribs={
'color': 5,
'layer': f'Estimated tangents ({METHOD})'
})
# local interpolation: a normalized tangent vector for each data point is required,
s = local_cubic_bspline_interpolation(
data, tangents=[t.normalize() for t in tangents])
# or set argument 'method' for automatic tangent estimation, default method is '5-points' interpolation
# s = local_cubic_bspline_interpolation(data, method=METHOD)
msp.add_spline(dxfattribs={
'color': 3,
'layer': f'Local interpolation ({METHOD})'
}).apply_construction_tool(s)
# global interpolation: take first and last vector from 'tangents' as start- and end tangent
m1, m2 = estimate_end_tangent_magnitude(data, method='chord')
s = global_bspline_interpolation(data,
tangents=(tangents[0].normalize(m1),
tangents[-1].normalize(m2)))
msp.add_spline(dxfattribs={
'color': 4,
'layer': f'Global interpolation ({METHOD})'
}).apply_construction_tool(s)
doc.set_modelspace_vport(5, center=(4, 1))
doc.saveas(DIR / f'sine-wave-{METHOD}.dxf')
'layer': 'BricsCAD B-spline',
'color': 2
})
zoom.extents(msp)
doc.saveas(DIR / 'concept-0-fit-points-only.dxf')
# ------------------------------------------------------------------------------
# SPLINE from fit points WITH given end tangents.
# ------------------------------------------------------------------------------
# 2. Store fit points, start- and end tangent values in DXF file:
doc, msp = setup()
# Tangent estimation method: "Total Chord Length",
# returns sum of chords for m1 and m2
m1, m2 = estimate_end_tangent_magnitude(points, method='chord')
# Multiply tangent vectors by total chord length for global interpolation:
start_tangent = Vec3.from_deg_angle(100) * m1
end_tangent = Vec3.from_deg_angle(-100) * m2
# Interpolate control vertices from fit points and end derivatives as constraints
s = global_bspline_interpolation(points,
degree=3,
tangents=(start_tangent, end_tangent))
msp.add_spline(dxfattribs={
'color': 4,
'layer': 'Global Interpolation'
}).apply_construction_tool(s)
# Result matches the BricsCAD interpolation if fit points, start- and end
# tangents are stored explicit in the DXF file.
spline = msp.add_spline(points,