Camera Perspective and Sphere Appearance in Three.js

Yes, the camera's perspective absolutely affects a sphere's apparent shape and size in 3D visualization. What you're observing is not an optical illusion but a fundamental aspect of perspective projection.

Why This Happens

In perspective projection:

1. Objects closer to the camera appear larger than objects of the same size that are farther away
2. The field of view (FOV) of the camera affects how pronounced this effect is
3. The position of objects within the view frustum affects their apparent proportions

In your image, the spheres appear to have inconsistent proportions because they're at different distances from the camera, causing perspective distortion.

Solutions

If you want consistent visual proportions regardless of distance, you have several options:

1. Use an Orthographic Camera instead of a Perspective Camera:

   JAVASCRIPTCopied
   const camera = new THREE.OrthographicCamera(
     width / -2, width / 2, 
     height / 2, height / -2, 
     near, far
   );

   Orthographic projection maintains size regardless of distance.

2. Adjust object scale based on distance:

   JAVASCRIPTCopied
   // Compensate for perspective by scaling objects based on distance
   const distanceToCamera = sphere.position.distanceTo(camera.position);
   const scaleFactor = distanceToCamera / referenceDistance;
   sphere.scale.set(scaleFactor, scaleFactor, scaleFactor);

3. Position all spheres at the same distance from the camera if your scene allows it.

4. Adjust the camera's FOV - a narrower field of view reduces perspective distortion.

The effect you're seeing is expected behavior in 3D graphics with perspective projection, not a bug or error in Three.js.