Contact Sets (EnableContactSetsCmd, EnableAllContactCmd, DisableAllContactCmd, ContactSetCmd, contact.edit/list/check): driving a joint stops where bodies of one set would pass through each other (bisection to the touch; penetration found by ray parity and depth on the tessellations); Motion Study (FusionMotionStudyCommand: joint values keyed along a timeline, motion.play, motion.export of occurrence poses per step as JSON or CSV without changing the design, contact-aware); Exploded views (explode.create automatic or by hand, explode.show without changing placements)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL

crates/engine/src/cmd/mod.rs

@@ -15,6 +15,7 @@ mod file;
 mod inspect;
 pub(crate) mod joints;
 mod measure_sel;
+pub(crate) mod motion;
 mod section;
 pub(crate) use measure_sel::measure_items;
 mod parameters;
@@ -142,6 +143,7 @@ pub fn command_specs() -> Vec<&'static CommandSpec> {
     v.extend(plastic::COMMANDS.iter());
     v.extend(component::COMMANDS.iter());
     v.extend(joints::COMMANDS.iter());
+    v.extend(motion::COMMANDS.iter());
     v.extend(browser::COMMANDS.iter());
     v.extend(delete::COMMANDS.iter());
     v.extend(edit::COMMANDS.iter());