Rendering Objects with Vastly Different Scales in Three.js

Rendering objects with such extreme scale differences (Sun being 463,800,000 times larger than Parker Solar Probe) is indeed challenging in 3D graphics. Here are some effective approaches to handle this situation:

1. Use Logarithmic Depth Buffer

One of the most effective solutions for extreme scale differences is enabling the logarithmic depth buffer:

JAVASCRIPTCopied
const renderer = new THREE.WebGLRenderer({
  logarithmicDepthBuffer: true
});

This significantly improves depth precision across large ranges by using a logarithmic scale for the depth buffer instead of a linear one.

2. Adjust Camera Settings Carefully

Fine-tune your perspective camera settings:

JAVASCRIPTCopied
// Use a relatively small near value but not too small
const camera = new THREE.PerspectiveCamera(
  45,                   // Field of view
  window.innerWidth / window.innerHeight, // Aspect ratio
  0.1,                  // Near plane (keep as large as possible)
  1e12                  // Far plane (adjust based on your scene)
);

3. Scale Your Universe

Instead of using actual astronomical scales, consider using a relative scale system:

JAVASCRIPTCopied
// Define a scale factor
const scaleFactor = 1e-9; // Adjust based on your needs

// Apply to object sizes
const sunRadius = realSunRadius * scaleFactor;
const probeSize = realProbeSize * scaleFactor;

// Maintain relative distances
const probeDistance = realProbeDistance * scaleFactor;

4. Multiple Camera Technique

Use different cameras for different scale objects:

JAVASCRIPTCopied
// Main scene camera for large objects
const mainCamera = new THREE.PerspectiveCamera(45, width/height, 1000, 1e12);

// Secondary camera for small objects
const detailCamera = new THREE.PerspectiveCamera(45, width/height, 0.1, 2000);

// Render in multiple passes
renderer.setViewport(0, 0, width, height);
renderer.render(mainScene, mainCamera);
renderer.clearDepth(); // Important!
renderer.render(detailScene, detailCamera);

5. Level of Detail System

Implement a dynamic LOD system that shows appropriate detail based on distance:

JAVASCRIPTCopied
const sunLOD = new THREE.LOD();

// Add different detail levels
const highDetailSun = createHighDetailSun();
const mediumDetailSun = createMediumDetailSun();
const lowDetailSun = createLowDetailSun();

sunLOD.addLevel(highDetailSun, 0);
sunLOD.addLevel(mediumDetailSun, 1000000);
sunLOD.addLevel(lowDetailSun, 10000000);

scene.add(sunLOD);

6. Use Specialized Renderers

For specific elements, consider using alternative renderers:

JAVASCRIPTCopied
// For distant objects like stars
const starField = new THREE.Points(starGeometry, starMaterial);
scene.add(starField);

// For UI elements showing probe details
const labelRenderer = new CSS2DRenderer();
labelRenderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(labelRenderer.domElement);

7. Optimize Transmission Resolution for Performance

If you're using materials with transmission effects (like for solar atmosphere):

JAVASCRIPTCopied
renderer.transmissionResolutionScale = 0.5; // Improve performance

These techniques can be combined for the best results. The most effective approach is likely using the logarithmic depth buffer along with a carefully designed relative scale system.