three
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JavaScript 3D library
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JavaScript
import NodeMaterial from './NodeMaterial.js';
import { dashSize, diffuseColor, gapSize, varyingProperty } from '../../nodes/core/PropertyNode.js';
import { attribute } from '../../nodes/core/AttributeNode.js';
import { cameraProjectionMatrix } from '../../nodes/accessors/Camera.js';
import { materialLineScale, materialLineDashSize, materialLineGapSize, materialLineDashOffset, materialLineWidth } from '../../nodes/accessors/MaterialNode.js';
import { modelViewMatrix } from '../../nodes/accessors/ModelNode.js';
import { positionGeometry } from '../../nodes/accessors/Position.js';
import { mix, smoothstep } from '../../nodes/math/MathNode.js';
import { Fn, float, vec2, vec3, vec4, If } from '../../nodes/tsl/TSLBase.js';
import { uv } from '../../nodes/accessors/UV.js';
import { screenDPR, viewport } from '../../nodes/display/ScreenNode.js';
import { viewportOpaqueMipTexture } from '../../nodes/display/ViewportTextureNode.js';
import { LineDashedMaterial } from '../LineDashedMaterial.js';
import { NoBlending } from '../../constants.js';
import { warnOnce } from '../../utils.js';
const _defaultValues = /*@__PURE__*/ new LineDashedMaterial();
/**
* Varying node representing the world position of the segment start in view space.
* Used for distance and coordinate calculations across the fragment shader.
* @type {VaryingNode<vec3>}
*/
const worldStart = varyingProperty( 'vec3', 'worldStart' );
/**
* Varying node representing the world position of the segment end in view space.
* Used for distance and coordinate calculations across the fragment shader.
* @type {VaryingNode<vec3>}
*/
const worldEnd = varyingProperty( 'vec3', 'worldEnd' );
/**
* Varying node representing the accumulated distance along the line.
* Crucial for correctly computing dashed line intervals in fragment stage.
* @type {VaryingNode<float>}
*/
const lineDistance = varyingProperty( 'float', 'lineDistance' );
/**
* Varying node representing the interpolated world/view position of the current fragment.
* Used for line/ray distance checks under perspective projection.
* @type {VaryingNode<vec4>}
*/
const worldPos = varyingProperty( 'vec4', 'worldPos' );
/**
* Trims the line segment to avoid rendering behind the camera near plane.
* Computes an interpolation factor (alpha) to clamp the segment's coordinate.
*
* @param {Object} inputs
* @param {Node<vec4>} inputs.start - Segment start position in view space.
* @param {Node<vec4>} inputs.end - Segment end position in view space.
* @returns {Node<float>} The interpolation factor (alpha) to trim the segment.
*/
const trimSegmentAlpha = Fn( ( { start, end } ) => {
const a = cameraProjectionMatrix.element( 2 ).element( 2 ); // 3nd entry in 3th column
const b = cameraProjectionMatrix.element( 3 ).element( 2 ); // 3nd entry in 4th column
// we need different nearEstimate formula for reversed and default depth buffer
// a is positive with a reversed depth buffer so it can be used for controlling the code flow
const nearEstimate = a.greaterThan( 0 ).select( b.negate().div( a.add( 1 ) ), b.mul( - 0.5 ).div( a ) );
return nearEstimate.sub( start.z ).div( end.z.sub( start.z ) );
}, { start: 'vec4', end: 'vec4', return: 'float' } );
/**
* Calculates the closest points on two 3D lines.
* Used for perspective-correct line rendering and coordinates interpolation.
*
* @param {Object} inputs
* @param {Node<vec3>} inputs.p1 - Start of line 1.
* @param {Node<vec3>} inputs.p2 - End of line 1.
* @param {Node<vec3>} inputs.p3 - Start of line 2.
* @param {Node<vec3>} inputs.p4 - End of line 2.
* @returns {Node<vec2>} A vec2 containing the parametric coordinates (mua, mub) of the closest points on line 1 and line 2.
*/
const closestLineToLine = Fn( ( { p1, p2, p3, p4 } ) => {
const p13 = p1.sub( p3 );
const p43 = p4.sub( p3 );
const p21 = p2.sub( p1 );
const d1343 = p13.dot( p43 );
const d4321 = p43.dot( p21 );
const d1321 = p13.dot( p21 );
const d4343 = p43.dot( p43 );
const d2121 = p21.dot( p21 );
const denom = d2121.mul( d4343 ).sub( d4321.mul( d4321 ) );
const numer = d1343.mul( d4321 ).sub( d1321.mul( d4343 ) );
const mua = numer.div( denom ).clamp();
const mub = d1343.add( d4321.mul( mua ) ).div( d4343 ).clamp();
return vec2( mua, mub );
}, { p1: 'vec3', p2: 'vec3', p3: 'vec3', p4: 'vec3', return: 'vec2' } );
/**
* TSL node acting as a custom Model-View-Projection (MVP) for fat lines,
* expanding 3D segments into screen/world-facing ribbons of a specified width.
*
* @tsl
* @type {Node<vec4>}
*/
const mvpLine = Fn( ( { material } ) => {
const useDash = material._useDash;
const useWorldUnits = material._useWorldUnits;
const instanceStart = attribute( 'instanceStart' );
const instanceEnd = attribute( 'instanceEnd' );
// camera space
const start = vec4( modelViewMatrix.mul( vec4( instanceStart, 1.0 ) ) ).toVar( 'start' );
const end = vec4( modelViewMatrix.mul( vec4( instanceEnd, 1.0 ) ) ).toVar( 'end' );
let distanceStart, distanceEnd;
if ( useDash ) {
distanceStart = float( attribute( 'instanceDistanceStart' ) ).toVar( 'distanceStart' );
distanceEnd = float( attribute( 'instanceDistanceEnd' ) ).toVar( 'distanceEnd' );
}
if ( useWorldUnits ) {
worldStart.assign( start.xyz );
worldEnd.assign( end.xyz );
}
const aspect = viewport.z.div( viewport.w );
// special case for perspective projection, and segments that terminate either in, or behind, the camera plane
// clearly the gpu firmware has a way of addressing this issue when projecting into ndc space
// but we need to perform ndc-space calculations in the shader, so we must address this issue directly
// perhaps there is a more elegant solution -- WestLangley
const perspective = cameraProjectionMatrix.element( 2 ).element( 3 ).equal( - 1.0 ); // 4th entry in the 3rd column
If( perspective, () => {
If( start.z.lessThan( 0.0 ).and( end.z.greaterThan( 0.0 ) ), () => {
const alpha = trimSegmentAlpha( { start, end } );
end.assign( vec4( mix( start.xyz, end.xyz, alpha ), end.w ) );
if ( useDash ) {
distanceEnd.assign( mix( distanceStart, distanceEnd, alpha ) );
}
} ).ElseIf( end.z.lessThan( 0.0 ).and( start.z.greaterThanEqual( 0.0 ) ), () => {
const alpha = trimSegmentAlpha( { start: end, end: start } );
start.assign( vec4( mix( end.xyz, start.xyz, alpha ), start.w ) );
if ( useDash ) {
distanceStart.assign( mix( distanceEnd, distanceStart, alpha ) );
}
} );
} );
if ( useDash ) {
const dashScaleNode = material.dashScaleNode ? float( material.dashScaleNode ) : materialLineScale;
const offsetNode = material.offsetNode ? float( material.offsetNode ) : materialLineDashOffset;
let lineDist = positionGeometry.y.lessThan( 0.5 ).select( dashScaleNode.mul( distanceStart ), dashScaleNode.mul( distanceEnd ) );
lineDist = lineDist.add( offsetNode );
lineDistance.assign( lineDist );
}
// clip space
const clipStart = cameraProjectionMatrix.mul( start );
const clipEnd = cameraProjectionMatrix.mul( end );
// ndc space
const ndcStart = clipStart.xyz.div( clipStart.w );
const ndcEnd = clipEnd.xyz.div( clipEnd.w );
// direction
const dir = ndcEnd.xy.sub( ndcStart.xy ).toVar();
// account for clip-space aspect ratio
dir.x.assign( dir.x.mul( aspect ) );
dir.assign( dir.normalize() );
const clip = vec4().toVar();
if ( useWorldUnits ) {
// get the offset direction as perpendicular to the view vector
const worldDir = end.xyz.sub( start.xyz ).normalize();
const tmpFwd = mix( start.xyz, end.xyz, 0.5 ).normalize();
const worldUp = worldDir.cross( tmpFwd ).normalize();
const worldFwd = worldDir.cross( worldUp );
worldPos.assign( positionGeometry.y.lessThan( 0.5 ).select( start, end ) );
// height offset
const hw = materialLineWidth.mul( 0.5 );
worldPos.addAssign( vec4( positionGeometry.x.lessThan( 0.0 ).select( worldUp.mul( hw ), worldUp.mul( hw ).negate() ), 0 ) );
// don't extend the line if we're rendering dashes because we
// won't be rendering the endcaps
if ( ! useDash ) {
// cap extension
worldPos.addAssign( vec4( positionGeometry.y.lessThan( 0.5 ).select( worldDir.mul( hw ).negate(), worldDir.mul( hw ) ), 0 ) );
// add width to the box
worldPos.addAssign( vec4( worldFwd.mul( hw ), 0 ) );
// endcaps
If( positionGeometry.y.greaterThan( 1.0 ).or( positionGeometry.y.lessThan( 0.0 ) ), () => {
worldPos.subAssign( vec4( worldFwd.mul( 2.0 ).mul( hw ), 0 ) );
} );
}
// project the worldpos
clip.assign( cameraProjectionMatrix.mul( worldPos ) );
// shift the depth of the projected points so the line
// segments overlap neatly
const clipPose = vec3().toVar();
clipPose.assign( positionGeometry.y.lessThan( 0.5 ).select( ndcStart, ndcEnd ) );
clip.z.assign( clipPose.z.mul( clip.w ) );
} else {
const offset = vec2( dir.y, dir.x.negate() ).toVar( 'offset' );
// undo aspect ratio adjustment
dir.x.assign( dir.x.div( aspect ) );
offset.x.assign( offset.x.div( aspect ) );
// sign flip
offset.assign( positionGeometry.x.lessThan( 0.0 ).select( offset.negate(), offset ) );
// endcaps
If( positionGeometry.y.lessThan( 0.0 ), () => {
offset.assign( offset.sub( dir ) );
} ).ElseIf( positionGeometry.y.greaterThan( 1.0 ), () => {
offset.assign( offset.add( dir ) );
} );
// adjust for linewidth
offset.assign( offset.mul( materialLineWidth ) );
// adjust for clip-space to screen-space conversion // maybe resolution should be based on viewport ...
offset.assign( offset.div( viewport.w.div( screenDPR ) ) );
// select end
clip.assign( positionGeometry.y.lessThan( 0.5 ).select( clipStart, clipEnd ) );
// back to clip space
offset.assign( offset.mul( clip.w ) );
clip.assign( clip.add( vec4( offset, 0, 0 ) ) );
}
return clip;
} )();
/**
* TSL fragment node that computes the shape/coverage (alpha) of the fat line segment.
* Handles dash/gap generation, alpha-to-coverage rendering, and round endcaps.
*
* @tsl
* @type {Node<float>}
*/
const alphaLine = Fn( ( { material, renderer } ) => {
const useAlphaToCoverage = material._useAlphaToCoverage;
const useDash = material._useDash;
const useWorldUnits = material._useWorldUnits;
const vUv = uv();
if ( useDash ) {
const dashSizeNode = material.dashSizeNode ? float( material.dashSizeNode ) : materialLineDashSize;
const gapSizeNode = material.gapSizeNode ? float( material.gapSizeNode ) : materialLineGapSize;
dashSize.assign( dashSizeNode );
gapSize.assign( gapSizeNode );
vUv.y.lessThan( - 1.0 ).or( vUv.y.greaterThan( 1.0 ) ).discard(); // discard endcaps
lineDistance.mod( dashSize.add( gapSize ) ).greaterThan( dashSize ).discard(); // todo - FIX
}
const alpha = float( 1 ).toVar( 'alpha' );
if ( useWorldUnits ) {
// Find the closest points on the view ray and the line segment
const rayEnd = worldPos.xyz.normalize().mul( 1e5 );
const lineDir = worldEnd.sub( worldStart );
const params = closestLineToLine( { p1: worldStart, p2: worldEnd, p3: vec3( 0.0, 0.0, 0.0 ), p4: rayEnd } );
const p1 = worldStart.add( lineDir.mul( params.x ) );
const p2 = rayEnd.mul( params.y );
const delta = p1.sub( p2 );
const len = delta.length();
const norm = len.div( materialLineWidth );
if ( ! useDash ) {
if ( useAlphaToCoverage && renderer.currentSamples > 0 ) {
const dnorm = norm.fwidth();
alpha.assign( smoothstep( dnorm.negate().add( 0.5 ), dnorm.add( 0.5 ), norm ).oneMinus() );
} else {
norm.greaterThan( 0.5 ).discard();
}
}
} else {
// round endcaps
if ( useAlphaToCoverage && renderer.currentSamples > 0 ) {
const a = vUv.x;
const b = vUv.y.greaterThan( 0.0 ).select( vUv.y.sub( 1.0 ), vUv.y.add( 1.0 ) );
const len2 = a.mul( a ).add( b.mul( b ) );
const dlen = float( len2.fwidth() ).toVar( 'dlen' );
If( vUv.y.abs().greaterThan( 1.0 ), () => {
alpha.assign( smoothstep( dlen.oneMinus(), dlen.add( 1 ), len2 ).oneMinus() );
} );
} else {
If( vUv.y.abs().greaterThan( 1.0 ), () => {
const a = vUv.x;
const b = vUv.y.greaterThan( 0.0 ).select( vUv.y.sub( 1.0 ), vUv.y.add( 1.0 ) );
const len2 = a.mul( a ).add( b.mul( b ) );
len2.greaterThan( 1.0 ).discard();
} );
}
}
return alpha;
} )();
/**
* This node material can be used to render lines with a size larger than one
* by representing them as instanced meshes.
*
* @augments NodeMaterial
*/
class Line2NodeMaterial extends NodeMaterial {
static get type() {
return 'Line2NodeMaterial';
}
/**
* Constructs a new node material for wide line rendering.
*
* @param {Object} [parameters={}] - The configuration parameter.
*/
constructor( parameters = {} ) {
super();
/**
* This flag can be used for type testing.
*
* @type {boolean}
* @readonly
* @default true
*/
this.isLine2NodeMaterial = true;
this.setDefaultValues( _defaultValues );
/**
* Whether vertex colors should be used or not.
*
* @type {boolean}
* @default false
*/
this.vertexColors = parameters.vertexColors;
/**
* The dash offset.
*
* @type {number}
* @default 0
*/
this.dashOffset = 0;
/**
* Defines the offset.
*
* @type {?Node<float>}
* @default null
*/
this.offsetNode = null;
/**
* Defines the dash scale.
*
* @type {?Node<float>}
* @default null
*/
this.dashScaleNode = null;
/**
* Defines the dash size.
*
* @type {?Node<float>}
* @default null
*/
this.dashSizeNode = null;
/**
* Defines the gap size.
*
* @type {?Node<float>}
* @default null
*/
this.gapSizeNode = null;
/**
* Blending is set to `NoBlending` since transparency
* is not supported, yet.
*
* @type {number}
* @default 0
*/
this.blending = NoBlending;
this._useDash = parameters.dashed;
this._useAlphaToCoverage = true;
this._useWorldUnits = false;
this.setValues( parameters );
}
/**
* Setups the diffuse color of the line material in the fragment stage.
* Overrides the base setup to incorporate line/dash rendering and blending.
*
* @param {NodeBuilder} builder - The current node builder.
*/
setupDiffuseColor( builder ) {
super.setupDiffuseColor( builder );
diffuseColor.a.mulAssign( alphaLine );
if ( this.vertexColors === true && builder.geometry.hasAttribute( 'instanceColorStart' ) ) {
const instanceColorStart = attribute( 'instanceColorStart' );
const instanceColorEnd = attribute( 'instanceColorEnd' );
const instanceColor = positionGeometry.y.lessThan( 0.5 ).select( instanceColorStart, instanceColorEnd );
diffuseColor.rgb.mulAssign( instanceColor );
}
if ( this.transparent ) {
diffuseColor.rgb.assign( diffuseColor.rgb.mul( diffuseColor.a ).add( viewportOpaqueMipTexture().rgb.mul( diffuseColor.a.oneMinus() ) ) );
}
}
/**
* Setups the position in clip space for the vertex stage of the fat line.
* Overrides the default model-view-projection to return the expanded fat line vertex coordinates.
*
* @param {NodeBuilder} builder - The current node builder.
* @return {Node<vec4>} The position of the fat line vertex in clip space.
*/
setupModelViewProjection( /*builder*/ ) {
return mvpLine;
}
/**
* Defines the lines color.
*
* @deprecated since r185. Use {@link NodeMaterial#colorNode} instead.
* @type {?Node<vec3>}
*/
get lineColorNode() {
return this.colorNode;
}
set lineColorNode( value ) {
warnOnce( 'Line2NodeMaterial: "lineColorNode" has been deprecated. Use "colorNode" instead.' ); // @deprecated r185
this.colorNode = value;
}
/**
* Whether the lines should sized in world units or not.
* When set to `false` the unit is pixel.
*
* @type {boolean}
* @default false
*/
get worldUnits() {
return this._useWorldUnits;
}
set worldUnits( value ) {
if ( this._useWorldUnits !== value ) {
this._useWorldUnits = value;
this.needsUpdate = true;
}
}
/**
* Whether the lines should be dashed or not.
*
* @type {boolean}
* @default false
*/
get dashed() {
return this._useDash;
}
set dashed( value ) {
if ( this._useDash !== value ) {
this._useDash = value;
this.needsUpdate = true;
}
}
/**
* Whether alpha to coverage should be used or not.
*
* @type {boolean}
* @default true
*/
get alphaToCoverage() {
return this._useAlphaToCoverage;
}
set alphaToCoverage( value ) {
if ( this._useAlphaToCoverage !== value ) {
this._useAlphaToCoverage = value;
this.needsUpdate = true;
}
}
}
export default Line2NodeMaterial;