How to Fix Hosting Timeout Errors in React with Three.js

I recently ran into a frustrating issue while hosting my React project that includes Three.js. After deploying, I kept getting a timeout error that essentially stopped the entire build process. The logs showed that some chunks were over 500 kB after minification, which was causing issues. Suggestions included using dynamic imports to split the code, adjusting the chunk size limit, or configuring Rollup’s manual chunk settings to handle the larger files better. Despite trying a few tweaks, the build kept timing out, showing an “execution timed out” message after nearly 18 minutes. I’m looking for effective ways to optimize the build and handle these larger chunks without running into time limits. Any insights or suggestions would be super helpful!

To solve this issue, we need to optimize the build for your React project using Three.js by reducing chunk sizes and preventing timeout errors. Here’s a step-by-step method to address each part of the problem:

Code-Splitting with Dynamic Imports:

Using dynamic imports allows your app to load parts of your code only when needed, instead of loading everything upfront. This is particularly useful when you have large libraries like Three.js that aren’t always required on the initial load.

1. Identify Modules to Split: Determine which components or features can be loaded later in your app.
2. Implement Dynamic Imports: Use the import() function to load these modules on demand. For example:

codeconst LazyLoadedComponent = React.lazy(() => import('./path/to/Component'));

Wrap in Suspense: Use React.Suspense to show a fallback (like a loading spinner) while the component loads.

<React.Suspense fallback={<div>Loading...</div>}>
   <LazyLoadedComponent />
</React.Suspense>

Manually Define Chunks with Rollup Options:

To have more control over how your code is split, use Rollup’s manualChunks option. This helps prevent creating overly large chunks that could exceed the size limit.

1. Open vite.config.js (or your build configuration file if not using Vite).
2. Add manualChunks under build.rollupOptions.output. You can create separate chunks for heavier dependencies:

export default {
  build: {
    rollupOptions: {
      output: {
        manualChunks: {
          'threejs': ['three'], // separates Three.js into its own chunk
          'react-vendor': ['react', 'react-dom'] // separates React libraries
        }
      }
    }
  }
};

This way, Three.js and other large dependencies load separately, reducing the initial chunk size and improving performance.

Increase the chunkSizeWarningLimit:

If you still see chunk size warnings, you can adjust the warning limit to allow larger chunk sizes temporarily while you work on other optimizations.

In vite.config.js, add chunkSizeWarningLimit under the build section:

export default {
  build: {
    chunkSizeWarningLimit: 1000 // Set the limit to 1000 KB or as needed
  }
};

While this won’t directly fix the performance issue, it will help avoid warnings if certain large chunks are unavoidable.

Use Tree Shaking to Remove Unused Code:

Tree shaking removes unused parts of your code and is particularly effective for libraries like Three.js, which may include modules you don’t use.

Import Only What You Need: Instead of importing the entire Three.js library, import specific modules: code

Ensure Tree Shaking is Enabled: Vite and Rollup generally have tree shaking enabled by default, but it helps to confirm you’re not importing the entire library unnecessarily.

import { WebGLRenderer, Scene, PerspectiveCamera } from 'three';

Optimize and Reduce Build Time:

Finally, optimize the overall build process to avoid timeout errors. This may include running a lighter build configuration in staging or removing any unused assets and files.

Summary

These steps should help you resolve the hosting error by breaking up the large chunks, reducing load times, and optimizing the build process. Here’s a checklist of actions:

1. Implement dynamic imports to code-split.
2. Use Rollup’s manualChunks option for more granular control.
3. Adjust the chunkSizeWarningLimit if needed.
4. Use tree shaking and specific imports for Three.js.
5. Optimize the build configuration to avoid unnecessary processing.

These methods together should reduce the chunk sizes, handle the timeout errors, and make the project easier to host and manage.

Final Thought:

Optimizing your React project with Three.js for hosting can seem daunting, especially when faced with chunk size and timeout errors. However, by using code-splitting, configuring manual chunks, and fine-tuning your build settings, you can efficiently reduce load times and prevent these issues. With thoughtful adjustments, your project will not only be easier to deploy but also provide a faster, smoother user experience. As you continue building, keep optimization strategies in mind to future-proof your app and keep it scalable, no matter how complex it becomes.