Module plugins 

Built-in plugins: skinning, animation, constraints, physics, skeleton. Built-in plugins for viewport-lib.

Each plugin lives in its own subdirectory and exposes its public surface through its own mod.rs. Consumers import from the plugin’s own path:

use viewport_lib::plugins::skeleton::{SkeletonPlugin, SkinnedActorPlugin};
use viewport_lib::plugins::skinning::SkinningPlugin;

This module intentionally does not re-export its children’s symbols at the top level: the path identifies which plugin each type belongs to, and the in-crate convention matches the shape used by external plugin crates (one public root per crate, not a shared namespace).

Plugin kinds currently shipped:

• Deformer plugins register a per-vertex deformation body against the mesh shader family. The only in-crate deformer is [skinning].
• Runtime plugins implement RuntimePlugin and are added to a ViewportRuntime via with_plugin. The in-crate set covers [animation], [constraint], [physics_lite], and the [skeleton] family.

Modules

animation

AnimationPlugin: keyframed and procedural transform animation.

constraint

ConstraintPlugin: spring-to-target, damping, and bounds constraints.

physics_lite

PhysicsLitePlugin: simple velocity integration, gravity, and bounded collision.

skeleton

Skeletal animation: substrate types, animation clips, and built-in plugins.

skinning

GPU skinning as a deformer-registry plugin.