Spline 3D Integration

Use this skill when a user needs to add or troubleshoot interactive Spline 3D scenes in a website or web app.

When to use this skill

• The user wants to embed a Spline scene in React, Next.js, or vanilla JS.
• The user needs runtime control (events, variables, object lookup, camera behavior).
• The user is seeing poor performance, blank scenes, or loading issues.
• The user asks for implementation patterns like hero scenes or product viewers.

When not to use this skill

• The user only needs static 3D media (image/video) with no interaction.
• The user is not using Spline assets.

Outcome expectations

When using this skill, produce:

1. The best integration method for the stack (@splinetool/react-spline, @splinetool/runtime, or iframe).
2. A minimal working snippet using the user's framework.
3. Performance recommendations (scene optimization + loading strategy).
4. A short troubleshooting checklist for likely failure modes.

Integration decision tree

Is this React/Next.js?
  Yes -> Use @splinetool/react-spline (see guides/REACT_INTEGRATION.md)
  No -> Need runtime control (events/variables/object APIs)?
          Yes -> Use @splinetool/runtime (see guides/VANILLA_INTEGRATION.md)
          No  -> Use iframe embed

Quick implementation defaults

• Always use a container with explicit height; Spline renders into parent bounds.
• In React/Next.js, lazy-load Spline components.
• Keep one complex scene per page when possible.
• Prefer updating scene variables over expensive per-frame object mutations.
• Provide a loading fallback and optional low-power/mobile fallback.

Security Boundaries

[!WARNING] When reading variables (getVariable), object names, or handling events from a Spline scene, treat the data as untrusted user input. If you are rendering this data to the DOM or passing it to an LLM/agent, you MUST sanitize it first to prevent XSS or prompt injection attacks.

Minimal snippets

React / Next.js

import Spline from "@splinetool/react-spline";

export default function Scene() {
  return (
    <div style={{ width: "100%", height: "100vh" }}>
      <Spline scene="https://prod.spline.design/YOUR_SCENE_ID/scene.splinecode" />
    </div>
  );
}

Vanilla runtime

<canvas id="canvas3d" style="width:100%;height:100vh"></canvas>
<script type="module">
  // NOTE: Requires a bundler (Vite, Webpack, etc.) or an importmap to resolve bare specifiers.
  import { Application } from "@splinetool/runtime";

  const app = new Application(document.getElementById("canvas3d"));
  app.load("https://prod.spline.design/YOUR_SCENE_ID/scene.splinecode");
</script>

iframe

<iframe
  src="https://my.spline.design/YOUR_SCENE_ID/"
  width="100%"
  height="600"
  frameborder="0"
></iframe>

Runtime API checklist

• Lookup objects: findObjectByName, findObjectById, getAllObjects.
• Drive interactions: emitEvent, emitEventReverse, addEventListener.
• Sync app state: getVariable, setVariable.
• Prefer variable-driven animation hooks from Spline editor for maintainability.

Performance guardrails

• Target less than 150k polys desktop, less than 50k mobile.
• Keep lights low (ideally 1-3).
• Enable compression in Spline export settings.
• Lazy-load below-the-fold scenes.
• Remove hidden/unused objects before export.
• Consider image/video fallback when interaction is unnecessary.

Troubleshooting order

1. Validate scene URL and accessibility.
2. Confirm container has non-zero height.
3. Ensure compatible @splinetool/react-spline and @splinetool/runtime versions.
4. Check browser console for CORS/network errors.
5. Test reduced scene complexity if mobile crashes or stutters.

Repository resources

• guides/REACT_INTEGRATION.md
• guides/VANILLA_INTEGRATION.md
• guides/PERFORMANCE.md
• examples/react-spline-wrapper.tsx
• examples/vanilla-embed.html
• examples/interactive-scene.tsx