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Bolt sweep

Many contacts

A robot-mounted scraper sweeps 96 loose nuts, bolts and washers into a bin.

0.00 s
The steel preset (the default), recordedon an NVIDIA RTX PRO 6000 Blackwell.

Run it

Terminal window
cd examples
# the default preset (steel), then the others
uv run shelf play bolt_sweep
# change solver settings live
uv run shelf tune bolt_sweep

Source: examples/shelf/02_many_contacts/bolt_sweep/ · ported from newton/examples/robot/example_steel_bolt_sweep.py @ skild-ai/newton 7565a26b1

Presets

PresetSolverStatusChecked
steeldefaultsteelworks2026-11-09, newton c42985a6c, NVIDIA RTX PRO 6000 Blackwell Server Edition

Solvers with no row are untested on this example. The full settings are inpresets.toml.

Code

examples/shelf/02_many_contacts/bolt_sweep/example.py
# SPDX-FileCopyrightText: Copyright (c) 2026 The Newton Developers
# SPDX-License-Identifier: Apache-2.0
# Modified for Steel Shelf: preset-driven execution and shared runner integration.


"""Sweep 96 loose nuts, bolts and washers into a bin using a robot-mounted scraper.


Command: python -m shelf run bolt_sweep
"""


import numpy as np
import warp as wp


import newton.examples
from common import presets


from newton.examples.robot import _bolt_sweep
from newton.examples.robot._tabletop_demo import TabletopDemo




class Example(TabletopDemo):
    task = "sweep"


    def __init__(self, viewer, args):
        self.preset = presets.load(__file__)
        # TabletopDemo (installed newton package) builds SolverSteel from these args, so fill them
        # from the preset before handing args over. Its frame rate is fixed at 60 Hz.
        args.substeps = self.preset.substeps
        args.iterations = self.preset.solver.need("iterations")
        args.solve_mode = self.preset.solver.need("solve_mode")
        args.contact_response = self.preset.solver.need("articulated_contact_response")
        super().__init__(viewer, args)


    @staticmethod
    def create_parser():
        # TabletopDemo.create_parser() without its solver-tuning arguments (--substeps, --iterations,
        # --solve-mode, --contact-response); those values now live in presets.toml.
        parser = newton.examples.create_parser()
        parser.set_defaults(num_frames=900)
        return parser


    def populate(self, builder, info, ee, down, fingers):
        _bolt_sweep.populate(builder, info, ee, down, wp.get_device())


    def test_final(self):
        """Verify that at least ``pile_required_count`` fasteners reach the collection bin."""
        self.check_capacity()
        poses = self.state_0.body_q.numpy()
        lo, hi = np.asarray(self.info["pile_bin_bounds"])
        centers = np.array(
            [
                np.asarray(wp.transform_point(wp.transform(*poses[b]), wp.vec3(*c)))
                for b, c in zip(self.info["pile_bodies"], self.info["pile_piece_centers"], strict=True)
            ]
        )
        count = np.count_nonzero(np.all((centers >= lo) & (centers <= hi), axis=1))
        required, total = self.info["pile_required_count"], len(self.info["pile_bodies"])
        assert count >= required, f"Only {count}/{total} fasteners collected"




if __name__ == "__main__":
    viewer, args = newton.examples.init(Example.create_parser())
    example = Example(viewer, args)
    newton.examples.run(example, args)

example.py on GitHub

Steel docs and tutorials are licensed under Apache-2.0. Third-party notices. "Skild", "Skild AI" and the Skild logo are trademarks of Skild AI and are not licensed under Apache-2.0.