SpringFX – High-Performance Bone Physics [v8.2.4]

High-performance bone physics for Blender

SpringFX gives hair, tails, ears, accessories and soft clothing believable secondary motion in Blender — in real time, with a compiled solver, and without leaving a single extra object, driver or constraint in your file.

Select bones, press Add Physics, hit play. When it looks right, bake it to keyframes or export it straight to VRChat PhysBones.

Every animation on this page was captured straight from the Blender viewport with the simulation running live (Solid shading, nothing rendered, nothing baked): exactly what you see while you work.

01 Anime hair
Bangs, side locks and twin tails, each in its own renamable group with its own settings. One click with the Hair preset, and the head works as a collider so the hair slides around it instead of through it.

02 Breast bounce
Two bones, location and rotation springs, the Breast preset. The character hops and the bounce follows with natural lag and overshoot.

03 Tails
A ten-bone tail follows every hop and turn of the body and settles on its own.

04 Collisions
A sphere collider pushes through nine hanging strands. Segment-based collision keeps every bone outside it, frame after frame.

05 Stiffness
Same motion, four groups, four Stiffness values: from Soft to Stiff. Every group keeps its own settings in one list.

New in 8.2.4: every platform, same result
Windows, macOS and Linux. The compiled solver now ships for all three, including Apple Silicon and Intel Macs.
Blender 4.5 LTS to 5.2. Intel Mac users, who can't move to Blender 5, get full support too.
Identical simulation everywhere. The same rig produces the same motion, bit for bit, on Windows, macOS and Linux. Verified by automated tests on every platform before each release.

Why SpringFX
Zero footprint. No extra objects, no drivers, no constraints. Your .blend stays clean, even with location springs enabled.
Fast enough to forget it's running. A compiled solver steps the whole rig once per frame. Measured: 0.537 ms per frame with collisions active.
Collisions that hold. Segment-based collision with multi-pass resolution against bone, sphere, capsule, plane and mesh colliders. Zero penetrations across thousands of controlled test samples.
Predictable, repeatable motion. A stable analytical integrator and bit-exact determinism: scrub, replay and re-bake and you get the same result every time.
VRChat PhysBones export. Tune the motion in Blender, validate it, then export the settings: endpoints, radius curves, colliders and angular limits. No bake needed: the settings travel, not the keys.
Organised by groups. Hair, tail and ears each get their own renamable group with their own settings and presets, all from one list.
Bake when you're done. Bake to keyframes with optional pre-roll warm-up for clean loops, then add post-bake noise. Existing animation on other bones is left untouched.
Deep control when you want it. Per-axis stiffness, chain falloff, lag, air drag, wind with turbulence, self-collision and viewport/render precision.

Made for
VRChat and VTuber avatars
Character animation where clean, linkable rigs matter
Studios and teams working across Windows, macOS and Linux
Game characters that need secondary motion tuned before export