React Three Fiber loaders

Inspect installed Fiber, Drei, Three.js, and React versions first. Examples use Fiber 9 / React 19. Verify actual asset paths, node names, formats, and compression; do not invent a model's structure.

Load and reuse a model

Mount below Canvas. Supply /models/robot.glb in the application. These clones have separate object transforms but intentionally share cached geometry/materials.

import { Suspense } from 'react'
import { Clone, useGLTF } from '@react-three/drei'

function Models() {
  const { scene } = useGLTF('/models/robot.glb')
  return (
    <group dispose={null}>
      <Clone object={scene} position={[-1.2, 0, 0]} />
      <Clone object={scene} position={[1.2, 0, 0]} />
    </group>
  )
}

export default function Example() {
  return (
    <Suspense fallback={null}>
      <Models />
    </Suspense>
  )
}

Loading decisions

• Prefer useGLTF for glTF/GLB; use useLoader with the matching Three.js loader for other formats. Fiber 9 also accepts an externally owned loader instance when configuration isolation is needed.
• Loader hooks suspend. Put boundaries around assets that should reveal together; separate boundaries for independent loading. Preload likely-needed assets ahead of interaction, not the entire catalog.
• Preloading starts a request; it does not guarantee instantaneous display or GPU shader compilation. Asset decoding and first rendering can still cost time.
• Conditional loading means conditionally mounting a child component that calls the hook. Do not pass null as a pretend URL or call a hook conditionally.
• Three.js addons use paths such as three/addons/loaders/GLTFLoader.js. Check installed exports for renamed loaders; modern Three.js uses HDRLoader where older examples used RGBELoader.
• Use gltfjsx with types when exposing named nodes/materials is useful, and inspect the generated result. For wrappers, use ThreeElements['group'], not the removed global JSX type namespace.

Cache, clones, and lifetime

• Treat cached loader results as shared. Mounting one Object3D under two parents moves it between them; clone the graph for repeated placement.
• Drei Clone supports ordinary graph duplication and skeleton-aware cloning. For independent animation mixers, a stable SkeletonUtils.clone root makes ownership explicit.
• A graph clone normally shares geometry, textures, and materials. Clone the specific material/texture before per-instance edits; deep-cloning everything wastes memory.
• Prevent an individual consumer from disposing shared cached resources (dispose={null} on the shared subtree). An application cache owner may release them only after all consumers are gone.
• Primitives are not automatically disposed by R3F. Neither useGLTF.clear(url) nor useLoader.clear(...) is a complete GPU cleanup operation.
• Do not clear caches during render, and do not mutate a cached scene's transforms/materials as a local setup shortcut.

Decoders and failure paths

• useGLTF integrates Draco/Meshopt support, but decoder URLs and loader configuration must match the asset and hosting policy. For KTX2 textures, configure a KTX2Loader with renderer capability detection before loading.
• Use the same loader/decoder settings for preload and actual load. Configure before requests start; later changes do not retroactively reparse an already cached result.
• Avoid creating a new decoder worker pool in every render or load callback. Give custom loader/decoder instances a deliberate owner and cleanup.
• Suspense handles pending work, not rejected requests. Use an error boundary with an explicit retry/remount strategy; cache eviction for retry belongs in a user action or controlled recovery path.
• Inside Canvas, use a Three.js fallback or Drei Html. Drei Loader is a DOM overlay and belongs outside Canvas.
• useProgress reflects the loading manager's activity, not necessarily one asset's byte-accurate completion. Avoid treating an unavailable Content-Length as a trustworthy denominator.
• Test network errors, CORS, decoder/transcoder hosting, and actual compressed assets. An uncompressed GLB smoke test does not validate every decoder path.

Sources

• Fiber useLoader, Drei useGLTF, Clone.
• GLTFLoader, KTX2Loader, SkeletonUtils.