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Morph Targets

Morph targets describe vertex-attribute deltas from a mesh's base geometry. luma.gl combines those targets using weights while preserving the existing scene nodes and model resources. Use morphs for expressions and shape changes; use skins for skeletal transforms. The two deformation mechanisms can be used together.

Example​

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The authored animation changes morph weights. An active animation track can overwrite weights set manually in a subsequent frame.

Update weights​

import {setMorphWeights} from '@luma.gl/engine';

// meshNode is a GroupNode with registered morph primitives and target state.
setMorphWeights(meshNode, [0.8, 0.2]);

The function updates registered morph primitives. It does not infer target deltas from an arbitrary mesh or create morph targets from a weights array.

MorphTargetState retains the primitive geometry, base attributes, and ordered target deltas. The scene node's morphMeshes record identifies the registered mesh groups; each affected ModelNode carries its morphTargets record. morphWeights records the current values. A morphWeightTransport record selects existing GPU weight storage when available.

When GPU weight transport exists, updating weights writes the corresponding buffer or texture. The fallback updates existing vertex buffers. Both paths preserve the scene hierarchy; target order must match the weights. See the morph-target API for lower-level buffer updates.

Animation and physics​

makeNodeAnimationBinding(meshNode, 'weights') connects engine tracks to registered morph state. Advance the animation before rendering and avoid competing writers to the same weights.

Visual morphing does not deform rigid collision shapes automatically. Keep collision geometry separate unless the application explicitly updates the physics representation.

Importing morphs​

The glTF adapter reads accessors, registers target state, and constructs animation bindings. The engine owns setMorphWeights() and runtime deformation updates. See Animation, Controllers, and glTF animation conversion.