Accueil / npm / three@0.172.0 / examples / jsm / tsl / display / SSRNode.js
SSRNode.js
import { NearestFilter, RenderTarget, Vector2, RendererUtils, QuadMesh, TempNode, NodeMaterial, NodeUpdateType } from 'three/webgpu';
import { reference, viewZToPerspectiveDepth, logarithmicDepthToViewZ, getScreenPosition, getViewPosition, sqrt, mul, div, cross, float, Continue, Break, Loop, int, max, abs, sub, If, dot, reflect, normalize, screenCoordinate, nodeObject, Fn, passTexture, uv, uniform, perspectiveDepthToViewZ, orthographicDepthToViewZ, vec2, vec3, vec4 } from 'three/tsl';
/** @module SSRNode **/
const _quadMesh = /*@__PURE__*/ new QuadMesh();
const _size = /*@__PURE__*/ new Vector2();
let _rendererState;
/**
* Post processing node for computing screen space reflections (SSR).
*
* Reference: {@link https://lettier.github.io/3d-game-shaders-for-beginners/screen-space-reflection.html}
*
* @augments TempNode
*/
class SSRNode extends TempNode {
static get type() {
return 'SSRNode';
}
/**
* Constructs a new SSR node.
*
* @param {Node<vec4>} colorNode - The node that represents the beauty pass.
* @param {Node<float>} depthNode - A node that represents the beauty pass's depth.
* @param {Node<vec3>} normalNode - A node that represents the beauty pass's normals.
* @param {Node<float>} metalnessNode - A node that represents the beauty pass's metalness.
* @param {Camera} camera - The camera the scene is rendered with.
*/
constructor( colorNode, depthNode, normalNode, metalnessNode, camera ) {
super( 'vec4' );
/**
* The node that represents the beauty pass.
*
* @type {Node<vec4>}
*/
this.colorNode = colorNode;
/**
* A node that represents the beauty pass's depth.
*
* @type {Node<float>}
*/
this.depthNode = depthNode;
/**
* A node that represents the beauty pass's normals.
*
* @type {Node<vec3>}
*/
this.normalNode = normalNode;
/**
* A node that represents the beauty pass's metalness.
*
* @type {Node<float>}
*/
this.metalnessNode = metalnessNode;
/**
* The camera the scene is rendered with.
*
* @type {Camera}
*/
this.camera = camera;
/**
* The resolution scale. By default SSR reflections
* are computed in half resolutions. Setting the value
* to `1` improves quality but also results in more
* computational overhead.
*
* @type {Number}
* @default 0.5
*/
this.resolutionScale = 0.5;
/**
* The `updateBeforeType` is set to `NodeUpdateType.FRAME` since the node renders
* its effect once per frame in `updateBefore()`.
*
* @type {String}
* @default 'frame'
*/
this.updateBeforeType = NodeUpdateType.FRAME;
/**
* The render target the SSR is rendered into.
*
* @private
* @type {RenderTarget}
*/
this._ssrRenderTarget = new RenderTarget( 1, 1, { depthBuffer: false, minFilter: NearestFilter, magFilter: NearestFilter } );
this._ssrRenderTarget.texture.name = 'SSRNode.SSR';
/**
* Controls how far a fragment can reflect
*
*
* @type {UniformNode<float>}
*/
this.maxDistance = uniform( 1 );
/**
* Controls the cutoff between what counts as a possible reflection hit and what does not.
*
* @type {UniformNode<float>}
*/
this.thickness = uniform( 0.1 );
/**
* Controls the transparency of the reflected colors.
*
* @type {UniformNode<float>}
*/
this.opacity = uniform( 1 );
/**
* Represents the projection matrix of the scene's camera.
*
* @private
* @type {UniformNode<mat4>}
*/
this._cameraProjectionMatrix = uniform( camera.projectionMatrix );
/**
* Represents the inverse projection matrix of the scene's camera.
*
* @private
* @type {UniformNode<mat4>}
*/
this._cameraProjectionMatrixInverse = uniform( camera.projectionMatrixInverse );
/**
* Represents the near value of the scene's camera.
*
* @private
* @type {ReferenceNode<float>}
*/
this._cameraNear = reference( 'near', 'float', camera );
/**
* Represents the far value of the scene's camera.
*
* @private
* @type {ReferenceNode<float>}
*/
this._cameraFar = reference( 'far', 'float', camera );
/**
* Whether the scene's camera is perspective or orthographic.
*
* @private
* @type {UniformNode<bool>}
*/
this._isPerspectiveCamera = uniform( camera.isPerspectiveCamera ? 1 : 0 );
/**
* The resolution of the pass.
*
* @private
* @type {UniformNode<vec2>}
*/
this._resolution = uniform( new Vector2() );
/**
* This value is derived from the resolution and restricts
* the maximum raymarching steps in the fragment shader.
*
* @private
* @type {UniformNode<float>}
*/
this._maxStep = uniform( 0 );
/**
* The material that is used to render the effect.
*
* @private
* @type {NodeMaterial}
*/
this._material = new NodeMaterial();
this._material.name = 'SSRNode.SSR';
/**
* The result of the effect is represented as a separate texture node.
*
* @private
* @type {PassTextureNode}
*/
this._textureNode = passTexture( this, this._ssrRenderTarget.texture );
}
/**
* Returns the result of the effect as a texture node.
*
* @return {PassTextureNode} A texture node that represents the result of the effect.
*/
getTextureNode() {
return this._textureNode;
}
/**
* Sets the size of the effect.
*
* @param {Number} width - The width of the effect.
* @param {Number} height - The height of the effect.
*/
setSize( width, height ) {
width = Math.round( this.resolutionScale * width );
height = Math.round( this.resolutionScale * height );
this._resolution.value.set( width, height );
this._maxStep.value = Math.round( Math.sqrt( width * width + height * height ) );
this._ssrRenderTarget.setSize( width, height );
}
/**
* This method is used to render the effect once per frame.
*
* @param {NodeFrame} frame - The current node frame.
*/
updateBefore( frame ) {
const { renderer } = frame;
_rendererState = RendererUtils.resetRendererState( renderer, _rendererState );
const size = renderer.getDrawingBufferSize( _size );
_quadMesh.material = this._material;
this.setSize( size.width, size.height );
// clear
renderer.setMRT( null );
renderer.setClearColor( 0x000000, 0 );
// ssr
renderer.setRenderTarget( this._ssrRenderTarget );
_quadMesh.render( renderer );
// restore
RendererUtils.restoreRendererState( renderer, _rendererState );
}
/**
* This method is used to setup the effect's TSL code.
*
* @param {NodeBuilder} builder - The current node builder.
* @return {PassTextureNode}
*/
setup( builder ) {
const uvNode = uv();
const pointToLineDistance = Fn( ( [ point, linePointA, linePointB ] )=> {
// https://mathworld.wolfram.com/Point-LineDistance3-Dimensional.html
return cross( point.sub( linePointA ), point.sub( linePointB ) ).length().div( linePointB.sub( linePointA ).length() );
} );
const pointPlaneDistance = Fn( ( [ point, planePoint, planeNormal ] )=> {
// https://mathworld.wolfram.com/Point-PlaneDistance.html
// https://en.wikipedia.org/wiki/Plane_(geometry)
// http://paulbourke.net/geometry/pointlineplane/
const d = mul( planeNormal.x, planePoint.x ).add( mul( planeNormal.y, planePoint.y ) ).add( mul( planeNormal.z, planePoint.z ) ).negate().toVar();
const denominator = sqrt( mul( planeNormal.x, planeNormal.x, ).add( mul( planeNormal.y, planeNormal.y ) ).add( mul( planeNormal.z, planeNormal.z ) ) ).toVar();
const distance = div( mul( planeNormal.x, point.x ).add( mul( planeNormal.y, point.y ) ).add( mul( planeNormal.z, point.z ) ).add( d ), denominator );
return distance;
} );
const getViewZ = Fn( ( [ depth ] ) => {
let viewZNode;
if ( this.camera.isPerspectiveCamera ) {
viewZNode = perspectiveDepthToViewZ( depth, this._cameraNear, this._cameraFar );
} else {
viewZNode = orthographicDepthToViewZ( depth, this._cameraNear, this._cameraFar );
}
return viewZNode;
} );
const sampleDepth = ( uv ) => {
const depth = this.depthNode.sample( uv ).r;
if ( builder.renderer.logarithmicDepthBuffer === true ) {
const viewZ = logarithmicDepthToViewZ( depth, this._cameraNear, this._cameraFar );
return viewZToPerspectiveDepth( viewZ, this._cameraNear, this._cameraFar );
}
return depth;
};
const ssr = Fn( () => {
const metalness = this.metalnessNode.sample( uvNode ).r;
// fragments with no metalness do not reflect their environment
metalness.equal( 0.0 ).discard();
// compute some standard FX entities
const depth = sampleDepth( uvNode ).toVar();
const viewPosition = getViewPosition( uvNode, depth, this._cameraProjectionMatrixInverse ).toVar();
const viewNormal = this.normalNode.rgb.normalize().toVar();
// compute the direction from the position in view space to the camera
const viewIncidentDir = ( ( this.camera.isPerspectiveCamera ) ? normalize( viewPosition ) : vec3( 0, 0, - 1 ) ).toVar();
// compute the direction in which the light is reflected on the surface
const viewReflectDir = reflect( viewIncidentDir, viewNormal ).toVar();
// adapt maximum distance to the local geometry (see https://www.mathsisfun.com/algebra/vectors-dot-product.html)
const maxReflectRayLen = this.maxDistance.div( dot( viewIncidentDir.negate(), viewNormal ) ).toVar();
// compute the maximum point of the reflection ray in view space
const d1viewPosition = viewPosition.add( viewReflectDir.mul( maxReflectRayLen ) ).toVar();
// check if d1viewPosition lies behind the camera near plane
If( this._isPerspectiveCamera.equal( float( 1 ) ).and( d1viewPosition.z.greaterThan( this._cameraNear.negate() ) ), () => {
// if so, ensure d1viewPosition is clamped on the near plane.
// this prevents artifacts during the ray marching process
const t = sub( this._cameraNear.negate(), viewPosition.z ).div( viewReflectDir.z );
d1viewPosition.assign( viewPosition.add( viewReflectDir.mul( t ) ) );
} );
// d0 and d1 are the start and maximum points of the reflection ray in screen space
const d0 = screenCoordinate.xy.toVar();
const d1 = getScreenPosition( d1viewPosition, this._cameraProjectionMatrix ).mul( this._resolution ).toVar();
// below variables are used to control the raymarching process
// total length of the ray
const totalLen = d1.sub( d0 ).length().toVar();
// offset in x and y direction
const xLen = d1.x.sub( d0.x ).toVar();
const yLen = d1.y.sub( d0.y ).toVar();
// determine the larger delta
// The larger difference will help to determine how much to travel in the X and Y direction each iteration and
// how many iterations are needed to travel the entire ray
const totalStep = max( abs( xLen ), abs( yLen ) ).toVar();
// step sizes in the x and y directions
const xSpan = xLen.div( totalStep ).toVar();
const ySpan = yLen.div( totalStep ).toVar();
const output = vec4( 0 ).toVar();
// the actual ray marching loop
// starting from d0, the code gradually travels along the ray and looks for an intersection with the geometry.
// it does not exceed d1 (the maximum ray extend)
Loop( { start: int( 0 ), end: int( this._maxStep ), type: 'int', condition: '<' }, ( { i } ) => {
// TODO: Remove this when Chrome is fixed, see https://issues.chromium.org/issues/372714384#comment14
If( metalness.equal( 0 ), () => {
Break();
} );
// stop if the maximum number of steps is reached for this specific ray
If( float( i ).greaterThanEqual( totalStep ), () => {
Break();
} );
// advance on the ray by computing a new position in screen space
const xy = vec2( d0.x.add( xSpan.mul( float( i ) ) ), d0.y.add( ySpan.mul( float( i ) ) ) ).toVar();
// stop processing if the new position lies outside of the screen
If( xy.x.lessThan( 0 ).or( xy.x.greaterThan( this._resolution.x ) ).or( xy.y.lessThan( 0 ) ).or( xy.y.greaterThan( this._resolution.y ) ), () => {
Break();
} );
// compute new uv, depth, viewZ and viewPosition for the new location on the ray
const uvNode = xy.div( this._resolution );
const d = sampleDepth( uvNode ).toVar();
const vZ = getViewZ( d ).toVar();
const vP = getViewPosition( uvNode, d, this._cameraProjectionMatrixInverse ).toVar();
const viewReflectRayZ = float( 0 ).toVar();
// normalized distance between the current position xy and the starting point d0
const s = xy.sub( d0 ).length().div( totalLen );
// depending on the camera type, we now compute the z-coordinate of the reflected ray at the current step in view space
If( this._isPerspectiveCamera.equal( float( 1 ) ), () => {
const recipVPZ = float( 1 ).div( viewPosition.z ).toVar();
viewReflectRayZ.assign( float( 1 ).div( recipVPZ.add( s.mul( float( 1 ).div( d1viewPosition.z ).sub( recipVPZ ) ) ) ) );
} ).Else( () => {
viewReflectRayZ.assign( viewPosition.z.add( s.mul( d1viewPosition.z.sub( viewPosition.z ) ) ) );
} );
// if viewReflectRayZ is less or equal than the real z-coordinate at this place, it potentially intersects the geometry
If( viewReflectRayZ.lessThanEqual( vZ ), () => {
// compute the distance of the new location to the ray in view space
// to clarify vP is the fragment's view position which is not an exact point on the ray
const away = pointToLineDistance( vP, viewPosition, d1viewPosition ).toVar();
// compute the minimum thickness between the current fragment and its neighbor in the x-direction.
const xyNeighbor = vec2( xy.x.add( 1 ), xy.y ).toVar(); // move one pixel
const uvNeighbor = xyNeighbor.div( this._resolution );
const vPNeighbor = getViewPosition( uvNeighbor, d, this._cameraProjectionMatrixInverse ).toVar();
const minThickness = vPNeighbor.x.sub( vP.x ).toVar();
minThickness.mulAssign( 3 ); // expand a bit to avoid errors
const tk = max( minThickness, this.thickness ).toVar();
If( away.lessThanEqual( tk ), () => { // hit
const vN = this.normalNode.sample( uvNode ).rgb.normalize().toVar();
If( dot( viewReflectDir, vN ).greaterThanEqual( 0 ), () => {
// the reflected ray is pointing towards the same side as the fragment's normal (current ray position),
// which means it wouldn't reflect off the surface. The loop continues to the next step for the next ray sample.
Continue();
} );
// this distance represents the depth of the intersection point between the reflected ray and the scene.
const distance = pointPlaneDistance( vP, viewPosition, viewNormal ).toVar();
If( distance.greaterThan( this.maxDistance ), () => {
// Distance exceeding limit: The reflection is potentially too far away and
// might not contribute significantly to the final color
Break();
} );
const op = this.opacity.mul( metalness ).toVar();
// distance attenuation (the reflection should fade out the farther it is away from the surface)
const ratio = float( 1 ).sub( distance.div( this.maxDistance ) ).toVar();
const attenuation = ratio.mul( ratio );
op.mulAssign( attenuation );
// fresnel (reflect more light on surfaces that are viewed at grazing angles)
const fresnelCoe = div( dot( viewIncidentDir, viewReflectDir ).add( 1 ), 2 );
op.mulAssign( fresnelCoe );
// output
const reflectColor = this.colorNode.sample( uvNode );
output.assign( vec4( reflectColor.rgb, op ) );
Break();
} );
} );
} );
return output;
} );
this._material.fragmentNode = ssr().context( builder.getSharedContext() );
this._material.needsUpdate = true;
//
return this._textureNode;
}
/**
* Frees internal resources. This method should be called
* when the effect is no longer required.
*/
dispose() {
this._ssrRenderTarget.dispose();
this._material.dispose();
}
}
export default SSRNode;
/**
* TSL function for creating screen space reflections (SSR).
*
* @function
* @param {Node<vec4>} colorNode - The node that represents the beauty pass.
* @param {Node<float>} depthNode - A node that represents the beauty pass's depth.
* @param {Node<vec3>} normalNode - A node that represents the beauty pass's normals.
* @param {Node<float>} metalnessNode - A node that represents the beauty pass's metalness.
* @param {Camera} camera - The camera the scene is rendered with.
* @returns {SSRNode}
*/
export const ssr = ( colorNode, depthNode, normalNode, metalnessNode, camera ) => nodeObject( new SSRNode( nodeObject( colorNode ), nodeObject( depthNode ), nodeObject( normalNode ), nodeObject( metalnessNode ), camera ) );