backward-roll

name	backward-roll
description	Performs a backward roll on the ground and comes back up, via a low sequence that drops root.y and sweeps root.faceDeg backward. Use when a command mentions backward roll, back roll, roll backwards, or roll over backward and up.
category	locomotion
disable-model-invocation	true
subskills	["move-torso","move-leg","balance-and-posture"]

backward-roll

Sit back low, tuck, roll backward (a backward faceDeg sweep while down), and recover to a stand.

Composes: move-torso + move-leg + balance-and-posture

How

• Use a sequence with loop:false. Sit/drop (root.y-0.5, legs tucked), roll back (root.y-0.75, faceDeg 0 → -180 → -360), rise to rest.
• durationMs ~1600.

Example

• "do a backward roll" -> {"durationMs":1600,"say":"Backward roll!","sequence":{"loop":false,"frames":[{"t":0,"pose":{"LeftUpLeg":[90,0,0],"LeftLeg":[110,0,0],"RightUpLeg":[90,0,0],"RightLeg":[110,0,0],"Spine":[30,0,0]},"root":{"y":-0.5,"z":-0.2}},{"t":0.5,"pose":{"LeftUpLeg":[120,0,0],"RightUpLeg":[120,0,0],"Spine":[20,0,0]},"root":{"y":-0.75,"z":-0.5,"faceDeg":-180}},{"t":1,"pose":{"LeftUpLeg":[0,0,180],"LeftLeg":[0,0,0],"RightUpLeg":[0,0,180],"RightLeg":[0,0,0],"Spine":[0,0,0]},"root":{"y":0,"z":-0.6,"faceDeg":-360}}]}}

Limits & posture

Keep ≥1 foot grounded except at a jump's airborne apex; stay inside human joint ranges and keep weight over the support — see balance-and-posture.