test/scripts/freestyle/styles/haloing.py

# SPDX-FileCopyrightText: 2008-2023 Blender Authors
#
# SPDX-License-Identifier: GPL-2.0-or-later

#  Author   : Stephane Grabli
#  Date     : 04/08/2005
#  Purpose  : This style module selects the lines that
#             are connected (in the image) to a specific
#             object and trims them in order to produce
#             a haloing effect around the target shape

from freestyle.chainingiterators import ChainSilhouetteIterator
from freestyle.predicates import (
    AndUP1D,
    NotUP1D,
    QuantitativeInvisibilityUP1D,
    TrueUP1D,
    pyIsOccludedByUP1D,
)
from freestyle.shaders import (
    IncreasingColorShader,
    IncreasingThicknessShader,
    SamplingShader,
    TipRemoverShader,
    pyTVertexRemoverShader,
)
from freestyle.types import Id, Operators


# id corresponds to the id of the target object
# (accessed by SHIFT+click)
id = Id(3, 0)
upred = AndUP1D(QuantitativeInvisibilityUP1D(0), pyIsOccludedByUP1D(id))
Operators.select(upred)
Operators.bidirectional_chain(ChainSilhouetteIterator(), NotUP1D(upred))
shaders_list = [
    IncreasingThicknessShader(3, 5),
    IncreasingColorShader(1, 0, 0, 1, 0, 1, 0, 1),
    SamplingShader(1.0),
    pyTVertexRemoverShader(),
    TipRemoverShader(3.0),
]
Operators.create(TrueUP1D(), shaders_list)