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73 lines
2.0 KiB
73 lines
2.0 KiB
#!/usr/local/bin/python3
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"""Script to generate a fixture of a box falling on a saw."""
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import argparse
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import json
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import pathlib
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import sys
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import numpy
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import shapely.geometry
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import shapely.ops
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from fixture_utils import *
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def generate_fixture(args):
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"""Generate a saw and block."""
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fixture = generate_custom_fixture(args)
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rigid_bodies = fixture["rigid_body_problem"]["rigid_bodies"]
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# Add the box
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box = generate_box_body(0.5, 0.5, [-0.5, 2.5], 0, 10)
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box["velocity"] = [1, -1, 0]
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rigid_bodies.append(box)
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# Add the saw
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num_teeth = 100
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saw_length = 10
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tooth_length = saw_length / num_teeth
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saw_polygons = [
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shapely.geometry.Polygon(
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numpy.array([[0.0, 0.0], [tooth_length, 0.0], [0.0, 1.0]]) +
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[0.8 * tooth_length * i, 0]) for i in range(num_teeth)
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]
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saw = shapely.ops.cascaded_union(saw_polygons)
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saw = shapely.geometry.polygon.orient(saw, 1)
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saw_polygons = [list(polygon.exterior.coords) for polygon in saw_polygons]
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saw_vertices = numpy.array(list(saw.exterior.coords)[:-1])
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saw_edges = generate_ngon_edges(saw_vertices.shape[0])
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rigid_bodies.append({
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"vertices": saw_vertices.tolist(),
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"polygons": saw_polygons,
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"edges": saw_edges.tolist(),
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"oriented": True,
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"velocity": [0.0, 0.0, 0.0],
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"is_dof_fixed": [True, True, True]
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})
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return fixture
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def main():
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"""Parse command-line arguments to generate the desired fixture."""
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parser = create_argument_parser("generate a block falling onto a saw")
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args = parser.parse_args()
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if args.out_path is None:
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directory = (pathlib.Path(__file__).resolve().parents[1] / "fixtures" /
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"saw")
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args.out_path = (directory /
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"saw-cor={:g}.json".format(args.restitution_coeff))
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args.out_path.parent.mkdir(parents=True, exist_ok=True)
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print_args(args)
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fixture = generate_fixture(args)
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save_fixture(fixture, args.out_path)
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if __name__ == "__main__":
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main()
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