Examples

The examples shelf in examples/ holds 81 examples, each with a solver preset for every solver that runs it. Each clip shows the Steel preset, coupled with another solver where the scene has cloth, sand or particles. Hover a card to play its clip (on a phone, the card in the middle of the screen plays); open it for the presets and code.

Run one from examples/ with uv run shelf play <name> (run is the same command), add--solver <preset> for another preset, or start uv run shelf play with no name to browse them. Setup is in the examples README.

Clips recorded on an NVIDIA RTX PRO 6000 Blackwell.

Basics

Basic dzhanibekov
The Dzhanibekov effect on a free T-shaped rigid body.
- steel
- xpbd
- vbd
- mujoco
- kamino
uv run shelf play basic_dzhanibekovSource
Basic joints
Joints of every type built with the ModelBuilder: ball, distance, prismatic, revolute and more.
- steel
- xpbd
- vbd
- kamino
uv run shelf play basic_jointsSource
Basic multi solver overlay
Four solvers run the same quadruple pendulum, overlaid as viewer layers.
- xpbd_featherstone_mujoco_kamino
- xpbd_featherstone_mujoco_kamino_steel
uv run shelf play basic_multi_solver_overlaySource
Basic pendulum
A double pendulum built with the ModelBuilder.
- steel
- xpbd
- kamino
uv run shelf play basic_pendulumSource
Basic shapes
Every collision shape the ModelBuilder offers, dropped together.
- steel
- xpbd
- vbd
- kamino
uv run shelf play basic_shapesSource
Basic urdf
A quadruped articulation loaded from URDF.
- steel
- xpbdunstable
- vbdunstable
- kamino
uv run shelf play basic_urdfSource
Speed caps
Gold bodies have a fall-speed cap, a spin cap and spin damping.
- steel
uv run shelf play body_limitsSource
Six-axis joints
A driven gantry, a universal joint and a gimbal.
- steel
uv run shelf play d6Source
Joint motors
Three arms driven to the same angle with different torque limits.
- steel
- steel_off
uv run shelf play drivesSource
Load-dependent friction
A hinge whose friction grows with load holds a heavy pendulum.
- steel
uv run shelf play load_frictionSource
Selection cartpole
Batch control of many cartpole worlds through an ArticulationView.
- steel
- mujoco
- kamino
uv run shelf play selection_cartpoleSource
Sleeping
Four stacks of ants topple into each other; sleeping islands turn grey.
- steel
- mujoco
uv run shelf play sleepingSource
Joint speed limits
Two double pendulums; the gold one has a speed limit.
- steel
uv run shelf play vel_limitSource

Basic contacts

Air hockey
A robot arm strikes a puck into the far goal.
- steel
uv run shelf play air_hockeySource
Balance bird
A procedural toy bird balances on a narrow pedestal.
- steel
- xpbd
- vbd
- mujoco
- featherstoneunstable
- kamino
uv run shelf play balance_birdSource
Basic conveyor
A baggage-claim conveyor: one rotating belt mesh on a kinematic root carries bags around.
- steel
- xpbd
- vbd
- kamino
uv run shelf play basic_conveyorSource
Basic conveyor forces
A multi-belt conveyor circuit moves boxes with a velocity field instead of belt friction.
- steel
- xpbd
- vbd
- mujoco
- kamino
uv run shelf play basic_conveyor_forcesSource
Beer pong
Throw a ping-pong ball: one bounce, then into the cup.
- steel
uv run shelf play beer_pongSource
Bounce
Balls bounce on pads from dead to very bouncy.
- steel
uv run shelf play bounceSource
Incline
A box and two stacks rest on a 22° slope without sliding.
- steel
- steel_off
uv run shelf play inclineSource
Kinematic paddle
A paddle on a fixed path sweeps boxes; one box ignores gravity.
- steel
uv run shelf play kinematicSource
Falling chain (mujoco.org)
Four interlocked thin chain links drop onto a catch bar and hang from it.
- steel
uv run shelf play mjorg_falling_chainSource
Luggage carousel (mujoco.org)
Three conveyor belts feed six bags onto a spinning baggage-claim carousel.
- steel
uv run shelf play mjorg_luggage_carouselSource
Magnetic door (mujoco.org)
A magnet strip snaps an ajar fridge door shut; a light tug cannot open it, a hard one can, and it swings back and latches.
- steel
uv run shelf play mjorg_magnetic_doorSource
Newton cradle
A five-ball Newton's cradle: one ball swings in, one swings out.
- steel
- xpbd
- vbd
- mujoco
- featherstone
- kamino
uv run shelf play newton_cradleSource
Overlapping boxes
20 boxes start deep inside each other and separate gently.
- steel
- steel_off
uv run shelf play overlapSource
Sliding blocks
Tall blocks slide across a grippy floor and tip over.
- steel
- steel_off
uv run shelf play rodsSource
Spinning top
A spinning chuck winds up a top and lets it go on its tip.
- steel
uv run shelf play spinning_topSource
Pinch grip
Fingertips pinch a bar off-centre; the gold pair holds it level.
- steel
uv run shelf play torsionSource

Many contacts

Bolt sweep
A robot-mounted scraper sweeps 96 loose nuts, bolts and washers into a bin.
- steel
uv run shelf play bolt_sweepSource
Brick pour
Pour toy bricks from a jar down three chutes.
- steel
uv run shelf play brick_pourSource
Card house
Four levels of playing cards held up by friction alone.
- steel
uv run shelf play card_houseSource
Crane wrecking ball
A UR10 grasps a toy crane and slews its ball into a dry-stacked miniature building.
- steel
uv run shelf play crane_wrecking_ballSource
Domino spiral
Dominoes along a spiral, the first one tilted to start the chain.
- steel
- xpbd
- vbd
- mujoco
- featherstone
- kamino
uv run shelf play domino_spiralSource
Jenga
Lift a loose block and add it to the top of the tower.
- steel
uv run shelf play jengaSource
Gothic arch (mujoco.org)
A mortarless pointed arch of seventeen loose stones stands on friction alone.
- steel
uv run shelf play mjorg_gothic_archSource
House of cards (mujoco.org)
A four-storey house of 26 thin playing cards stands on friction alone.
- steel
uv run shelf play mjorg_house_of_cardsSource
Sleeping dominos (mujoco.org)
One tilted domino starts a wave through 96 sleeping dominoes; each row wakes as it arrives.
- steel
uv run shelf play mjorg_sleeping_dominosSource
Mass-ratio stack
Six cubes, each three times heavier than the one below.
- steel
uv run shelf play ratio_stackSource
Shapes in box
Rigid bodies of every shape type dropped into a box container.
- steel
- vbd
uv run shelf play shapes_in_boxSource
Trebuchet
A counterweight trebuchet hurls a boulder at a brick wall.
- steel
uv run shelf play trebuchetSource

Mesh and SDF contacts

Contacts rj45 plug
An RJ45 plug moved into its socket with the translation gizmo.
- vbd
- steel_vbd
uv run shelf play contacts_rj45_plugSource
Franka plate rack
A Franka lifts a dinner plate and places it in a wire rack beside two resting plates.
- steel
uv run shelf play franka_plate_rackSource
Nut bolt hydro
A nut on a bolt with hydroelastic mesh contacts.
- steel
- xpbd
- mujoco
- kamino
uv run shelf play nut_bolt_hydroSource
Nut bolt sdf
A nut on a bolt with SDF mesh contacts.
- steel
- xpbd
- mujoco
- kamino
uv run shelf play nut_bolt_sdfSource
Robot panda hydro
A Franka Panda picks and places with hydroelastic contacts and inverse kinematics.
- steel
- mujoco
uv run shelf play robot_panda_hydroSource
Viaduct kit
A robot arm seats the top tier of a toy viaduct onto its pegs.
- steel
uv run shelf play viaduct_kitSource

Mimic joints

Basic mimic joint
A lead screw: a prismatic nut joint mimics a revolute screw joint.
- steel
- xpbd
- vbd
- mujoco
- featherstone
- semi_implicit
uv run shelf play basic_mimic_jointSource

Looped linkages

Linkages
Copied joint motion and a closed four-bar linkage.
- steel
uv run shelf play linkagesSource
Delta robot
Three driven arms swing a level platform in circles on parallelogram forearms.
- steel
uv run shelf play loop_delta_robotSource
Loop dr testmech
The DR TestMech in many worlds on Kamino.
- steel
- kamino
uv run shelf play loop_dr_testmechSource
Loop fourbar
A four-bar linkage in many worlds on Kamino.
- steel
- kamino
uv run shelf play loop_fourbarSource
Hoberman sphere
A Hoberman sphere of 120 bars and 240 hinges opens and closes from one driven hub.
- steel
- mujoco
- kamino
- mujoco_all
- steel_all
- kamino_all
uv run shelf play loop_hoberman_sphereSource
Parallelogram gripper
One slider opens and closes two parallelogram fingers whose jaws stay vertical.
- steel
uv run shelf play loop_parallel_gripperSource

Looped linkages with contacts

Anymal d many worlds
ANYmal D in many worlds on Kamino.
- steel
- kamino
uv run shelf play anymal_d_many_worldsSource
Loop dr legs
DR Legs in many worlds on Kamino.
- steel
- kamino
- kamino_dvi
uv run shelf play loop_dr_legsSource

Articulations

Balance board
Restore balance by placing the missing counterweight.
- steel
uv run shelf play balance_boardSource
Box turn
Two arms pinch a box between their fingertips, flip it and turn it.
- steel
uv run shelf play box_turnSource
Controller operational space hybrid force motion
Operational-space hybrid force and motion control on two robots.
- steel
- mujoco
uv run shelf play controller_operational_space_hybrid_force_motionSource
Drawer and fork
Pull open a drawer, then put a fork in its tray.
- steel
uv run shelf play drawer_forkSource
Ragdoll
A 10-part ragdoll tumbles down a staircase.
- steel
uv run shelf play ragdollSource
Robot allegro hand
An Allegro hand articulation from USD.
- steel
- mujoco
- kamino
uv run shelf play robot_allegro_handSource
Robot anymal d
ANYmal D in many worlds on MuJoCo or Kamino.
- steel
- mujoco
- kamino
uv run shelf play robot_anymal_dSource
Robot asroballet
LQR and learned-policy control of the asRoBallet robot.
- steel
- mujoco
uv run shelf play robot_asroballetSource
Robot cartpole
A cartpole articulation from USD.
- steel
- mujoco
- kamino
uv run shelf play robot_cartpoleSource
Robot g1
A Unitree G1 humanoid from USD.
- steel
- mujoco
- kamino
uv run shelf play robot_g1Source
Robot policy
Robots pretrained in IsaacLab with RL, run with their policies.
- steel
- mujoco
uv run shelf play robot_policySource
Robot ur10
A UR10 arm from USD under a joint-space controller.
- steel
- mujoco
- kamino
uv run shelf play robot_ur10Source
Toaster
Insert a slice of bread and press the toaster lever.
- steel
uv run shelf play toasterSource
Toy train
Push a toy train along a track on its free-spinning wheels.
- steel
uv run shelf play toy_trainSource

Thin shells and rods

Franka cable ik pick place
A Franka FR3 uses GPU IK to pick up a deformable cable and move it.
- steel_vbd
- mujoco_vbd
uv run shelf play franka_cable_ik_pick_placeSource

Coupling

Ball tied to cloth
A rigid ball tied to the centre of a pinned VBD cloth sheet.
- steel_vbd
- mujoco_vbd
- kamino_vbd
uv run shelf play ball_tied_to_clothSource
Boxes chain cloth soft
Rigid boxes and a pendulum chain meet a cloth sheet and soft bodies.
- steel_vbd
- vbd
- mujoco_vbd
- kamino_vbd
uv run shelf play boxes_chain_cloth_softSource
Boxes into sand
Rigid boxes fall into a granular MPM bed.
- steel_implicit_mpm
- mujoco_implicit_mpm
- kamino_implicit_mpm
uv run shelf play boxes_into_sandSource
Fourbar split solvers
A four-bar linkage split between Kamino and MuJoCo or Steel.
- kamino_steel
- kamino_mujoco
uv run shelf play fourbar_split_solversSource
Franka chain on cable
A Franka picks and places a short rigid chain tied to a VBD cable.
- steel_xpbd
- steel_vbd
- mujoco_xpbd
- mujoco_vbd
uv run shelf play franka_chain_on_cableSource
Franka cloth block
A rigid block rests on a VBD cloth hammock a Franka handles.
- steel_vbd
- mujoco_vbd
uv run shelf play franka_cloth_blockSource
Franka shirt fold stack
A Franka folds and stacks a T-shirt with two-way cloth coupling.
- steel_vbd
- mujoco_vbd
uv run shelf play franka_shirt_fold_stackSource
Particle pad drawer
An XPBD particle pad falls into a ball-jointed rigid drawer.
- steel_xpbd
- semi_implicit_xpbd
- mujoco_xpbd
uv run shelf play particle_pad_drawerSource
Proxy joint gripper
A palm and two cube fingers grip a VBD soft grid.
- steel_vbd
- mujoco_vbd
uv run shelf play proxy_joint_gripperSource
Shapes onto sand
A dozen rigid shapes dropped onto MPM material with two-way coupling.
- steel_implicit_mpm
- mujoco_implicit_mpm
uv run shelf play shapes_onto_sandSource

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.