Fixing Image Capture in Three.js

Based on your issue, it appears you're experiencing a color space conversion problem when capturing and saving images from your Three.js scene. The first image shows what you see on screen, while the second image (saved version) has different colors/brightness.

This is likely due to the fact that Three.js renders in linear color space, but your display shows images in sRGB color space. When you capture the canvas directly, you're getting the linear color space data without the proper conversion.

Solution

You can use the ImageUtils.sRGBToLinear method to convert your captured image to the correct color space before saving. Here's how you might approach this:

JAVASCRIPTCopied
// After rendering your scene
const renderer = yourRenderer; // Your Three.js renderer
const canvas = renderer.domElement;

// Option 1: Using toDataURL directly (may not preserve color space)
// const dataURL = canvas.toDataURL('image/jpeg');

// Option 2: Using Three.js ImageUtils to handle color space correctly
// Import the necessary modules
import { ImageUtils } from 'three';

// Get data URL with proper color space conversion
const dataURL = ImageUtils.getDataURL(canvas);

// Create a download link
const link = document.createElement('a');
link.href = dataURL;
link.download = 'scene-capture.jpg';
link.click();

Alternatively, you can set the renderer's output encoding to sRGB before capturing:

JAVASCRIPTCopied
// Before capturing
renderer.outputEncoding = THREE.sRGBEncoding;
renderer.render(scene, camera);

// Capture the image
const dataURL = renderer.domElement.toDataURL('image/jpeg');

// Create download link
const link = document.createElement('a');
link.href = dataURL;
link.download = 'scene-capture.jpg';
link.click();

// Optionally reset encoding if needed
renderer.outputEncoding = THREE.LinearEncoding; // If you were using linear before

This should help ensure that what you see on screen is what gets saved in your image file.