GroundedSkybox.js•1.41 kB
import { Mesh, MeshBasicMaterial, SphereGeometry, Vector3 } from 'three';
/**
* A ground-projected skybox. The height is how far the camera that took the photo was above the ground -
* a larger value will magnify the downward part of the image. By default the object is centered at the camera,
* so it is often helpful to set skybox.position.y = height to put the ground at the origin. Set the radius
* large enough to ensure your user's camera stays inside.
*/
class GroundedSkybox extends Mesh {
constructor( map, height, radius, resolution = 128 ) {
if ( height <= 0 || radius <= 0 || resolution <= 0 ) {
throw new Error( 'GroundedSkybox height, radius, and resolution must be positive.' );
}
const geometry = new SphereGeometry( radius, 2 * resolution, resolution );
geometry.scale( 1, 1, - 1 );
const pos = geometry.getAttribute( 'position' );
const tmp = new Vector3();
for ( let i = 0; i < pos.count; ++ i ) {
tmp.fromBufferAttribute( pos, i );
if ( tmp.y < 0 ) {
// Smooth out the transition from flat floor to sphere:
const y1 = - height * 3 / 2;
const f =
tmp.y < y1 ? - height / tmp.y : ( 1 - tmp.y * tmp.y / ( 3 * y1 * y1 ) );
tmp.multiplyScalar( f );
tmp.toArray( pos.array, 3 * i );
}
}
pos.needsUpdate = true;
super( geometry, new MeshBasicMaterial( { map, depthWrite: false } ) );
}
}
export { GroundedSkybox };