Softie Adds XPBD Collisions to Blender

For those who don’t know the tool: aflatsprite develops Blender tools including Softie Collision System, a Geometry Nodes setup aimed at animation and sculpting. It sits between mesh preparation and downstream rendering, providing an immediate deformation path plus a separate XPBD simulation modifier for Blender 5.2.

Fake physics, deliberately

Softie’s main collision mode is not a conventional simulation. It evaluates surface contact without storing per-frame velocity or history, which makes it useful for interactive deformation during animation and sculpting. The developer explicitly limits it to surface deformation and recommends simple manifold geometry. Very deep penetrations can break the raycast vectors, so it is better at controlled contact than rescuing meshes already occupying the same postcode.

Artists can adjust Object Hardness, assign hardness through a named attribute or weight-painted group, restrict evaluation through attribute selection and work with multiple collision objects. Self-collision is also supported in the non-simulation system, with an automatic check and fix for non-manifold self-collision cases.

XPBD when history matters

A second collision type uses Blender’s XPBD cloth dynamics solver and requires Blender 5.2. Softie adds custom pin and force algorithms plus pressure, recovery controls and dynamic masking. The simulation system now lives in a separate modifier and is explicitly marked experimental by the developer.

That distinction is important. The instant system is useful when the required result is plausible contact deformation. XPBD is the route for frame-to-frame dynamics where velocity, accumulated motion and solver state actually matter. They are two production strategies, not quality settings for the same algorithm.

Useful numbers, properly labelled

The developer reports sub-10 ms node-tree calculation time for simple geometry with multiple collision objects on an Intel Core i7-14700F. A separate optimisation reduced reported self-collision evaluation from 60 ms to 30 ms on heavier meshes. These are vendor measurements, not universal performance guarantees, and no formal benchmark scene is published. Softie is documented for Blender 5.1 to 5.2, while its XPBD mode specifically requires Blender 5.2. The product page does not document separate operating-system requirements, GPU requirements or a specific processing backend, so CUDA, Metal or other acceleration claims would be guesswork.

Cheap tool, expensive topology

Softie is currently listed at $9.99 under a GPL licence. The listing does not publish a subscription period, maintenance plan, trial condition or update-entitlement policy, so those should not be inferred from the purchase price.

Studios should test Softie on representative production plushies (Let’s make this phrase a thing!), animation ranges, and target Blender builds before deploying it into an active pipeline.