The centralHorizontalAngle property of the XREquirectLayer interface represents the central horizontal angle in radians for the sphere.

A number representing the central horizontal angle in radians for the sphere. Setting centralHorizontalAngle to a value less than 0 will set it to 0 and setting it to a value higher than 2π will set it to 2π.

The XRWebGLBinding.createEquirectLayer() method creates an equirect layer and allows specifying a centralHorizontalAngle. The XREquirectLayer.centralHorizontalAngle property can be used after layer creation to get the central horizontal angle used or to set it to a new one.

const equirectLayer = xrGlBinding.createEquirectLayer({
  space: xrReferenceSpace,
  viewPixelWidth: 1200,
  viewPixelHeight: 600,
  centralHorizontalAngle: 2 * Math.PI,
  upperVerticalAngle: Math.PI / 2.0,
  lowerVerticalAngle: -Math.PI / 2.0,
  radius: 0,
});

equirectLayer.centralHorizontalAngle; // 6.283185307179586

• XREquirectLayer.radius
• XREquirectLayer.lowerVerticalAngle
• XREquirectLayer.upperVerticalAngle