328 lines
8.0 KiB
JavaScript
328 lines
8.0 KiB
JavaScript
import {
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Color,
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Matrix4,
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Mesh,
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PerspectiveCamera,
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Plane,
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Quaternion,
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ShaderMaterial,
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UniformsUtils,
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Vector3,
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Vector4,
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WebGLRenderTarget,
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HalfFloatType
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} from 'three';
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class Refractor extends Mesh {
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constructor( geometry, options = {} ) {
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super( geometry );
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this.isRefractor = true;
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this.type = 'Refractor';
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this.camera = new PerspectiveCamera();
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const scope = this;
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const color = ( options.color !== undefined ) ? new Color( options.color ) : new Color( 0x7F7F7F );
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const textureWidth = options.textureWidth || 512;
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const textureHeight = options.textureHeight || 512;
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const clipBias = options.clipBias || 0;
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const shader = options.shader || Refractor.RefractorShader;
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const multisample = ( options.multisample !== undefined ) ? options.multisample : 4;
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//
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const virtualCamera = this.camera;
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virtualCamera.matrixAutoUpdate = false;
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virtualCamera.userData.refractor = true;
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//
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const refractorPlane = new Plane();
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const textureMatrix = new Matrix4();
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// render target
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const renderTarget = new WebGLRenderTarget( textureWidth, textureHeight, { samples: multisample, type: HalfFloatType } );
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// material
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this.material = new ShaderMaterial( {
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name: ( shader.name !== undefined ) ? shader.name : 'unspecified',
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uniforms: UniformsUtils.clone( shader.uniforms ),
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vertexShader: shader.vertexShader,
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fragmentShader: shader.fragmentShader,
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transparent: true // ensures, refractors are drawn from farthest to closest
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} );
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this.material.uniforms[ 'color' ].value = color;
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this.material.uniforms[ 'tDiffuse' ].value = renderTarget.texture;
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this.material.uniforms[ 'textureMatrix' ].value = textureMatrix;
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// functions
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const visible = ( function () {
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const refractorWorldPosition = new Vector3();
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const cameraWorldPosition = new Vector3();
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const rotationMatrix = new Matrix4();
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const view = new Vector3();
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const normal = new Vector3();
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return function visible( camera ) {
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refractorWorldPosition.setFromMatrixPosition( scope.matrixWorld );
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cameraWorldPosition.setFromMatrixPosition( camera.matrixWorld );
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view.subVectors( refractorWorldPosition, cameraWorldPosition );
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rotationMatrix.extractRotation( scope.matrixWorld );
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normal.set( 0, 0, 1 );
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normal.applyMatrix4( rotationMatrix );
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return view.dot( normal ) < 0;
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};
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} )();
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const updateRefractorPlane = ( function () {
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const normal = new Vector3();
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const position = new Vector3();
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const quaternion = new Quaternion();
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const scale = new Vector3();
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return function updateRefractorPlane() {
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scope.matrixWorld.decompose( position, quaternion, scale );
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normal.set( 0, 0, 1 ).applyQuaternion( quaternion ).normalize();
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// flip the normal because we want to cull everything above the plane
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normal.negate();
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refractorPlane.setFromNormalAndCoplanarPoint( normal, position );
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};
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} )();
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const updateVirtualCamera = ( function () {
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const clipPlane = new Plane();
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const clipVector = new Vector4();
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const q = new Vector4();
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return function updateVirtualCamera( camera ) {
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virtualCamera.matrixWorld.copy( camera.matrixWorld );
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virtualCamera.matrixWorldInverse.copy( virtualCamera.matrixWorld ).invert();
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virtualCamera.projectionMatrix.copy( camera.projectionMatrix );
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virtualCamera.far = camera.far; // used in WebGLBackground
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// The following code creates an oblique view frustum for clipping.
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// see: Lengyel, Eric. “Oblique View Frustum Depth Projection and Clipping”.
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// Journal of Game Development, Vol. 1, No. 2 (2005), Charles River Media, pp. 5–16
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clipPlane.copy( refractorPlane );
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clipPlane.applyMatrix4( virtualCamera.matrixWorldInverse );
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clipVector.set( clipPlane.normal.x, clipPlane.normal.y, clipPlane.normal.z, clipPlane.constant );
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// calculate the clip-space corner point opposite the clipping plane and
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// transform it into camera space by multiplying it by the inverse of the projection matrix
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const projectionMatrix = virtualCamera.projectionMatrix;
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q.x = ( Math.sign( clipVector.x ) + projectionMatrix.elements[ 8 ] ) / projectionMatrix.elements[ 0 ];
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q.y = ( Math.sign( clipVector.y ) + projectionMatrix.elements[ 9 ] ) / projectionMatrix.elements[ 5 ];
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q.z = - 1.0;
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q.w = ( 1.0 + projectionMatrix.elements[ 10 ] ) / projectionMatrix.elements[ 14 ];
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// calculate the scaled plane vector
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clipVector.multiplyScalar( 2.0 / clipVector.dot( q ) );
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// replacing the third row of the projection matrix
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projectionMatrix.elements[ 2 ] = clipVector.x;
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projectionMatrix.elements[ 6 ] = clipVector.y;
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projectionMatrix.elements[ 10 ] = clipVector.z + 1.0 - clipBias;
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projectionMatrix.elements[ 14 ] = clipVector.w;
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};
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} )();
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// This will update the texture matrix that is used for projective texture mapping in the shader.
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// see: http://developer.download.nvidia.com/assets/gamedev/docs/projective_texture_mapping.pdf
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function updateTextureMatrix( camera ) {
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// this matrix does range mapping to [ 0, 1 ]
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textureMatrix.set(
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0.5, 0.0, 0.0, 0.5,
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0.0, 0.5, 0.0, 0.5,
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0.0, 0.0, 0.5, 0.5,
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0.0, 0.0, 0.0, 1.0
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);
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// we use "Object Linear Texgen", so we need to multiply the texture matrix T
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// (matrix above) with the projection and view matrix of the virtual camera
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// and the model matrix of the refractor
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textureMatrix.multiply( camera.projectionMatrix );
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textureMatrix.multiply( camera.matrixWorldInverse );
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textureMatrix.multiply( scope.matrixWorld );
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}
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//
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function render( renderer, scene, camera ) {
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scope.visible = false;
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const currentRenderTarget = renderer.getRenderTarget();
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const currentXrEnabled = renderer.xr.enabled;
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const currentShadowAutoUpdate = renderer.shadowMap.autoUpdate;
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renderer.xr.enabled = false; // avoid camera modification
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renderer.shadowMap.autoUpdate = false; // avoid re-computing shadows
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renderer.setRenderTarget( renderTarget );
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if ( renderer.autoClear === false ) renderer.clear();
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renderer.render( scene, virtualCamera );
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renderer.xr.enabled = currentXrEnabled;
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renderer.shadowMap.autoUpdate = currentShadowAutoUpdate;
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renderer.setRenderTarget( currentRenderTarget );
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// restore viewport
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const viewport = camera.viewport;
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if ( viewport !== undefined ) {
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renderer.state.viewport( viewport );
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}
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scope.visible = true;
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}
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//
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this.onBeforeRender = function ( renderer, scene, camera ) {
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// ensure refractors are rendered only once per frame
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if ( camera.userData.refractor === true ) return;
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// avoid rendering when the refractor is viewed from behind
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if ( ! visible( camera ) === true ) return;
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// update
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updateRefractorPlane();
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updateTextureMatrix( camera );
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updateVirtualCamera( camera );
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render( renderer, scene, camera );
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};
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this.getRenderTarget = function () {
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return renderTarget;
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};
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this.dispose = function () {
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renderTarget.dispose();
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scope.material.dispose();
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};
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}
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}
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Refractor.RefractorShader = {
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name: 'RefractorShader',
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uniforms: {
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'color': {
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value: null
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},
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'tDiffuse': {
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value: null
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},
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'textureMatrix': {
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value: null
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}
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},
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vertexShader: /* glsl */`
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uniform mat4 textureMatrix;
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varying vec4 vUv;
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void main() {
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vUv = textureMatrix * vec4( position, 1.0 );
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gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );
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}`,
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fragmentShader: /* glsl */`
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uniform vec3 color;
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uniform sampler2D tDiffuse;
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varying vec4 vUv;
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float blendOverlay( float base, float blend ) {
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return( base < 0.5 ? ( 2.0 * base * blend ) : ( 1.0 - 2.0 * ( 1.0 - base ) * ( 1.0 - blend ) ) );
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}
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vec3 blendOverlay( vec3 base, vec3 blend ) {
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return vec3( blendOverlay( base.r, blend.r ), blendOverlay( base.g, blend.g ), blendOverlay( base.b, blend.b ) );
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}
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void main() {
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vec4 base = texture2DProj( tDiffuse, vUv );
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gl_FragColor = vec4( blendOverlay( base.rgb, color ), 1.0 );
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#include <tonemapping_fragment>
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#include <colorspace_fragment>
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}`
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};
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export { Refractor };
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