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mrdoobmrdoob
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Merge pull request #17872 from gkjohnson/linesegments2-raycast
Examples: Add raycast support for LineSegments2
2 parents 6c05134 + dc96a86 commit 6a21666

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2 files changed

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lines changed

‎examples/js/lines/LineSegments2.js‎

Lines changed: 141 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -52,6 +52,146 @@ THREE.LineSegments2.prototype = Object.assign( Object.create( THREE.Mesh.prototy
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};
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55-
}() )
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}() ),
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raycast: ( function () {
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var start = new THREE.Vector4();
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var end = new THREE.Vector4();
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var ssOrigin = new THREE.Vector4();
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var ssOrigin3 = new THREE.Vector3();
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var mvMatrix = new THREE.Matrix4();
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var line = new THREE.Line3();
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var closestPoint = new THREE.Vector3();
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return function raycast( raycaster, intersects ) {
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if ( raycaster.camera === null ) {
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console.error( 'LineSegments2: "Raycaster.camera" needs to be set in order to raycast against LineSegments2.' );
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}
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var ray = raycaster.ray;
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var camera = raycaster.camera;
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var projectionMatrix = camera.projectionMatrix;
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var geometry = this.geometry;
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var material = this.material;
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var resolution = material.resolution;
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var lineWidth = material.linewidth;
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var instanceStart = geometry.attributes.instanceStart;
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var instanceEnd = geometry.attributes.instanceEnd;
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// pick a point 1 unit out along the ray to avoid the ray origin
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// sitting at the camera origin which will cause "w" to be 0 when
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// applying the projection matrix.
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ray.at( 1, ssOrigin );
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// ndc space [ - 1.0, 1.0 ]
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ssOrigin.w = 1;
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ssOrigin.applyMatrix4( camera.matrixWorldInverse );
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ssOrigin.applyMatrix4( projectionMatrix );
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ssOrigin.multiplyScalar( 1 / ssOrigin.w );
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// screen space
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ssOrigin.x *= resolution.x / 2;
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ssOrigin.y *= resolution.y / 2;
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ssOrigin.z = 0;
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ssOrigin3.copy( ssOrigin );
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var matrixWorld = this.matrixWorld;
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mvMatrix.multiplyMatrices( camera.matrixWorldInverse, matrixWorld );
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for ( var i = 0, l = instanceStart.count; i < l; i ++ ) {
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start.fromBufferAttribute( instanceStart, i );
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end.fromBufferAttribute( instanceEnd, i );
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start.w = 1;
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end.w = 1;
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// camera space
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start.applyMatrix4( mvMatrix );
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end.applyMatrix4( mvMatrix );
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// clip space
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start.applyMatrix4( projectionMatrix );
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end.applyMatrix4( projectionMatrix );
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// ndc space [ - 1.0, 1.0 ]
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start.multiplyScalar( 1 / start.w );
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end.multiplyScalar( 1 / end.w );
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// skip the segment if it's outside the camera near and far planes
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var isBehindCameraNear = start.z < - 1 && end.z < - 1;
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var isPastCameraFar = start.z > 1 && end.z > 1;
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if ( isBehindCameraNear || isPastCameraFar ) {
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continue;
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}
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// screen space
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start.x *= resolution.x / 2;
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start.y *= resolution.y / 2;
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end.x *= resolution.x / 2;
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end.y *= resolution.y / 2;
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// create 2d segment
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line.start.copy( start );
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line.start.z = 0;
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line.end.copy( end );
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line.end.z = 0;
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// get closest point on ray to segment
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var param = line.closestPointToPointParameter( ssOrigin3, true );
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line.at( param, closestPoint );
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// check if the intersection point is within clip space
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var zPos = THREE.Math.lerp( start.z, end.z, param );
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var isInClipSpace = zPos >= -1 && zPos <= 1;
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var isInside = ssOrigin3.distanceTo( closestPoint ) < lineWidth * 0.5;
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if ( isInClipSpace && isInside ) {
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line.start.fromBufferAttribute( instanceStart, i );
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line.end.fromBufferAttribute( instanceEnd, i );
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line.start.applyMatrix4( matrixWorld );
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line.end.applyMatrix4( matrixWorld );
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var pointOnLine = new THREE.Vector3();
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var point = new THREE.Vector3();
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ray.distanceSqToSegment( line.start, line.end, point, pointOnLine );
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intersects.push( {
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point: point,
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pointOnLine: pointOnLine,
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distance: ray.origin.distanceTo( point ),
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object: this,
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face: null,
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faceIndex: i,
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uv: null,
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uv2: null,
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} );
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}
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}
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}
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} () )
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} );

‎examples/jsm/lines/LineSegments2.js‎

Lines changed: 146 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -6,8 +6,12 @@
66
import {
77
InstancedInterleavedBuffer,
88
InterleavedBufferAttribute,
9+
Line3,
10+
Math as _Math,
11+
Matrix4,
912
Mesh,
10-
Vector3
13+
Vector3,
14+
Vector4
1115
} from "../../../build/three.module.js";
1216
import { LineSegmentsGeometry } from "../lines/LineSegmentsGeometry.js";
1317
import { LineMaterial } from "../lines/LineMaterial.js";
@@ -61,7 +65,147 @@ LineSegments2.prototype = Object.assign( Object.create( Mesh.prototype ), {
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};
6367

64-
}() )
68+
}() ),
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raycast: ( function () {
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var start = new Vector4();
73+
var end = new Vector4();
74+
75+
var ssOrigin = new Vector4();
76+
var ssOrigin3 = new Vector3();
77+
var mvMatrix = new Matrix4();
78+
var line = new Line3();
79+
var closestPoint = new Vector3();
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81+
return function raycast( raycaster, intersects ) {
82+
83+
if ( raycaster.camera === null ) {
84+
85+
console.error( 'LineSegments2: "Raycaster.camera" needs to be set in order to raycast against LineSegments2.' );
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87+
}
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var ray = raycaster.ray;
90+
var camera = raycaster.camera;
91+
var projectionMatrix = camera.projectionMatrix;
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var geometry = this.geometry;
94+
var material = this.material;
95+
var resolution = material.resolution;
96+
var lineWidth = material.linewidth;
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98+
var instanceStart = geometry.attributes.instanceStart;
99+
var instanceEnd = geometry.attributes.instanceEnd;
100+
101+
// pick a point 1 unit out along the ray to avoid the ray origin
102+
// sitting at the camera origin which will cause "w" to be 0 when
103+
// applying the projection matrix.
104+
ray.at( 1, ssOrigin );
105+
106+
// ndc space [ - 1.0, 1.0 ]
107+
ssOrigin.w = 1;
108+
ssOrigin.applyMatrix4( camera.matrixWorldInverse );
109+
ssOrigin.applyMatrix4( projectionMatrix );
110+
ssOrigin.multiplyScalar( 1 / ssOrigin.w );
111+
112+
// screen space
113+
ssOrigin.x *= resolution.x / 2;
114+
ssOrigin.y *= resolution.y / 2;
115+
ssOrigin.z = 0;
116+
117+
ssOrigin3.copy( ssOrigin );
118+
119+
var matrixWorld = this.matrixWorld;
120+
mvMatrix.multiplyMatrices( camera.matrixWorldInverse, matrixWorld );
121+
122+
for ( var i = 0, l = instanceStart.count; i < l; i ++ ) {
123+
124+
start.fromBufferAttribute( instanceStart, i );
125+
end.fromBufferAttribute( instanceEnd, i );
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127+
start.w = 1;
128+
end.w = 1;
129+
130+
// camera space
131+
start.applyMatrix4( mvMatrix );
132+
end.applyMatrix4( mvMatrix );
133+
134+
// clip space
135+
start.applyMatrix4( projectionMatrix );
136+
end.applyMatrix4( projectionMatrix );
137+
138+
// ndc space [ - 1.0, 1.0 ]
139+
start.multiplyScalar( 1 / start.w );
140+
end.multiplyScalar( 1 / end.w );
141+
142+
// skip the segment if it's outside the camera near and far planes
143+
var isBehindCameraNear = start.z < - 1 && end.z < - 1;
144+
var isPastCameraFar = start.z > 1 && end.z > 1;
145+
if ( isBehindCameraNear || isPastCameraFar ) {
146+
147+
continue;
148+
149+
}
150+
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// screen space
152+
start.x *= resolution.x / 2;
153+
start.y *= resolution.y / 2;
154+
155+
end.x *= resolution.x / 2;
156+
end.y *= resolution.y / 2;
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158+
// create 2d segment
159+
line.start.copy( start );
160+
line.start.z = 0;
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162+
line.end.copy( end );
163+
line.end.z = 0;
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165+
// get closest point on ray to segment
166+
var param = line.closestPointToPointParameter( ssOrigin3, true );
167+
line.at( param, closestPoint );
168+
169+
// check if the intersection point is within clip space
170+
var zPos = _Math.lerp( start.z, end.z, param );
171+
var isInClipSpace = zPos >= -1 && zPos <= 1;
172+
173+
var isInside = ssOrigin3.distanceTo( closestPoint ) < lineWidth * 0.5;
174+
175+
if ( isInClipSpace && isInside ) {
176+
177+
line.start.fromBufferAttribute( instanceStart, i );
178+
line.end.fromBufferAttribute( instanceEnd, i );
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180+
line.start.applyMatrix4( matrixWorld );
181+
line.end.applyMatrix4( matrixWorld );
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183+
var pointOnLine = new Vector3();
184+
var point = new Vector3();
185+
186+
ray.distanceSqToSegment( line.start, line.end, point, pointOnLine );
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188+
intersects.push( {
189+
190+
point: point,
191+
pointOnLine: pointOnLine,
192+
distance: ray.origin.distanceTo( point ),
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194+
object: this,
195+
face: null,
196+
faceIndex: i,
197+
uv: null,
198+
uv2: null,
199+
200+
} );
201+
202+
}
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}
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}
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208+
} () )
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66210
} );
67211

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