three
Version:
JavaScript 3D library
69 lines (46 loc) • 2.26 kB
JavaScript
console.warn( "THREE.ShadowMesh: As part of the transition to ES6 Modules, the files in 'examples/js' were deprecated in May 2020 (r117) and will be deleted in December 2020 (r124). You can find more information about developing using ES6 Modules in https://threejs.org/docs/#manual/en/introduction/Installation." );
/**
* A shadow Mesh that follows a shadow-casting Mesh in the scene, but is confined to a single plane.
*/
THREE.ShadowMesh = function ( mesh ) {
var shadowMaterial = new THREE.MeshBasicMaterial( {
color: 0x000000,
transparent: true,
opacity: 0.6,
depthWrite: false
} );
THREE.Mesh.call( this, mesh.geometry, shadowMaterial );
this.meshMatrix = mesh.matrixWorld;
this.frustumCulled = false;
this.matrixAutoUpdate = false;
};
THREE.ShadowMesh.prototype = Object.create( THREE.Mesh.prototype );
THREE.ShadowMesh.prototype.constructor = THREE.ShadowMesh;
THREE.ShadowMesh.prototype.update = function () {
var shadowMatrix = new THREE.Matrix4();
return function ( plane, lightPosition4D ) {
// based on https://www.opengl.org/archives/resources/features/StencilTalk/tsld021.htm
var dot = plane.normal.x * lightPosition4D.x +
plane.normal.y * lightPosition4D.y +
plane.normal.z * lightPosition4D.z +
- plane.constant * lightPosition4D.w;
var sme = shadowMatrix.elements;
sme[ 0 ] = dot - lightPosition4D.x * plane.normal.x;
sme[ 4 ] = - lightPosition4D.x * plane.normal.y;
sme[ 8 ] = - lightPosition4D.x * plane.normal.z;
sme[ 12 ] = - lightPosition4D.x * - plane.constant;
sme[ 1 ] = - lightPosition4D.y * plane.normal.x;
sme[ 5 ] = dot - lightPosition4D.y * plane.normal.y;
sme[ 9 ] = - lightPosition4D.y * plane.normal.z;
sme[ 13 ] = - lightPosition4D.y * - plane.constant;
sme[ 2 ] = - lightPosition4D.z * plane.normal.x;
sme[ 6 ] = - lightPosition4D.z * plane.normal.y;
sme[ 10 ] = dot - lightPosition4D.z * plane.normal.z;
sme[ 14 ] = - lightPosition4D.z * - plane.constant;
sme[ 3 ] = - lightPosition4D.w * plane.normal.x;
sme[ 7 ] = - lightPosition4D.w * plane.normal.y;
sme[ 11 ] = - lightPosition4D.w * plane.normal.z;
sme[ 15 ] = dot - lightPosition4D.w * - plane.constant;
this.matrix.multiplyMatrices( shadowMatrix, this.meshMatrix );
};
}();