Adjusting Line Width in AxesHelper

Unfortunately, directly modifying the line width of an AxesHelper is not straightforward because AxesHelper creates its own LineBasicMaterial instances internally with default properties.

To customize the line width, you'll need to create your own custom axes helper instead of using the built-in AxesHelper. Here's how you can create a custom axes helper with thicker lines:

JAVASCRIPTCopied
function createCustomAxesHelper(size = 1, lineWidth = 3) {
  const axes = new THREE.Object3D();
  
  // Materials for each axis
  const matX = new THREE.LineBasicMaterial({ color: 0xff0000, linewidth: lineWidth });
  const matY = new THREE.LineBasicMaterial({ color: 0x00ff00, linewidth: lineWidth });
  const matZ = new THREE.LineBasicMaterial({ color: 0x0000ff, linewidth: lineWidth });
  
  // Geometries
  const geometry = new THREE.BufferGeometry();
  
  // X-axis
  geometry.setAttribute('position', new THREE.Float32BufferAttribute([0, 0, 0, size, 0, 0], 3));
  const xAxis = new THREE.Line(geometry, matX);
  
  // Y-axis
  const geometryY = geometry.clone();
  geometryY.setAttribute('position', new THREE.Float32BufferAttribute([0, 0, 0, 0, size, 0], 3));
  const yAxis = new THREE.Line(geometryY, matY);
  
  // Z-axis
  const geometryZ = geometry.clone();
  geometryZ.setAttribute('position', new THREE.Float32BufferAttribute([0, 0, 0, 0, 0, size], 3));
  const zAxis = new THREE.Line(geometryZ, matZ);
  
  axes.add(xAxis);
  axes.add(yAxis);
  axes.add(zAxis);
  
  return axes;
}

// Usage
const customAxes = createCustomAxesHelper(5, 3);
scene.add(customAxes);

Important Note: While the linewidth property exists in LineBasicMaterial, it's important to know that most WebGL implementations only support a line width of 1, regardless of the value you set. This is a limitation of WebGL itself, not Three.js. The line width property may work on some systems but is not reliable across all platforms.

For more reliable thick lines, you might want to consider:

1. Using tubes (THREE.TubeGeometry) instead of lines
2. Using a library like THREE.MeshLine
3. Using a shader-based approach for line rendering

These alternatives will give you more control over the appearance of your axes helper.