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Tutorial Intermediate

Physics and jiggle

Dial in breast, butt, hair and skirt movement with Dynamic Bones and HS2PE, add collision, and fake wind.

Breasts, hips, skirts, and hair all move through different systems in HS2 Studio. Getting a natural result means tuning jiggle strength, adding collision so parts do not pass through each other, and setting up Dynamic Bones on anything that should sway on its own. This guide walks through each piece.

Breast and butt jiggle

Base bounce for the butt comes from the HS2BoobSettings plugin, not from HS2PE directly. Open its Lower Body tab and enable the override butt physics option. That reveals four sliders controlling how much the butt reacts to movement and how quickly it settles. A good starting point is around 6/6/20/20; push the first two higher for more sway, and the last two higher for a slower, heavier settle.

For breasts on a character you added directly in Studio, rather than one loaded from a card with saved settings, open HS2PE and adjust the breast gravity and force sliders per character. These control how much the breasts sag under gravity and how strongly they respond to motion, and they are the closest thing to a manual bounce toggle for a Studio-added character.

Quick jiggle test: press M to toggle the built-in mouse-hover jiggle. Hovering the cursor over a jiggle-enabled body part triggers a bounce, which is a fast way to preview slider changes without moving the character or scrubbing the timeline.

Add collision so parts actually touch

By default, breasts, hands, and props pass straight through each other. Fixing that means adding a Dynamic Bone collider on whichever part should push back.

  • In HS2PE, attach a Dynamic Bone collider to the part that needs to react, then use Studio’s parent/child function to attach it to the object that should trigger it, for example parenting a collider to a hand node so it makes breasts respond to touch.
  • For props that should collide but do not have a built-in collider, attach a collider to the tip of the object, then use Node Constraints (Ctrl+I) to parent the collider to the object and align it.
  • Once a collider is placed, adjust its position and size in HS2PE until contact registers where you expect.
Colliders can go invisible: if you lose track of where one actually sits, open the Colliders window inside HS2PE's Advanced Mode to see and reposition it directly. Parenting a small visible placeholder object to the collider also gives you a persistent visual reference while you line it up.

Hair and skirt movement (Dynamic Bones)

Hair, skirts, and loose cloth all move using Dynamic Bones, a separate system from the breast/butt jiggle above. Right-click the HS2PE icon and go to Advanced > Dynamic Bones to see the bone chain for whatever item you have selected.

Three sliders do most of the work:

SliderEffect
StiffnessHow strongly the bone resists moving from its rest position. Higher values keep hair and cloth closer to their default shape.
ElasticityHow much a bone stretches away from its parent before snapping back. Higher values feel bouncier and slower to settle.
GravityConstant pull on the bone chain, mainly on the Y axis. This is what makes hair and skirts hang down and settle instead of floating in place.

If a skirt gets pushed into odd positions by collision, check for blendshapes in HS2PE first, then try enabling FK on the skirt’s bone chain (the cf_J_Legsk bones) so you can pose it by hand instead of letting the physics fight the collider. See posing by hand and IK/FK for how FK chains work. If a piece of clothing has dynamic bones you want off entirely, switch HS2PE to Advanced Mode to reveal its Clothes tab, which lists per-item bone toggles.


Faking wind

Studio has no real wind system. Any “blowing” look on hair or a skirt comes from tuning the same stiffness, elasticity, and gravity values above, not from an actual wind force. Lower stiffness and elasticity slightly and lean on gravity so hair and cloth hang and sway naturally as the character or camera moves, then key those values over time in Timeline if you want a gust at a specific moment.

Be wary of automatic "wind" plugins: third-party plugins that add idle wind motion can make hair twitch on its own every few seconds regardless of the scene, or even leave the scene selector unresponsive when switching scenes. If you notice motion you did not set up, or scenes stop loading correctly, disable any installed wind-effect plugin before troubleshooting further.

The green collider grid

If a green wireframe grid appears over a character, that is the physics collider visualization, not a bug. It is toggled by a checkbox in the Character Creator; unchecking it hides the grid again without affecting the underlying physics.


Once jiggle, collision, and Dynamic Bones are all behaving, check fixing hair problems if hair still clips or looks stiff, Advanced Bones (ABMX) for deeper per-bone control, and fixing clothing clipping if a skirt or top still pokes through the body after these changes.

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