three 基础库
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import {
Box3,
Line3,
Plane,
Sphere,
Triangle,
Vector3
} from '../../../build/three.module.js';
import { Capsule } from '../math/Capsule.js';
const _v1 = new Vector3();
const _v2 = new Vector3();
const _plane = new Plane();
const _line1 = new Line3();
const _line2 = new Line3();
const _sphere = new Sphere();
const _capsule = new Capsule();
class Octree {
constructor( box ) {
this.triangles = [];
this.box = box;
this.subTrees = [];
}
addTriangle( triangle ) {
if ( ! this.bounds ) this.bounds = new Box3();
this.bounds.min.x = Math.min( this.bounds.min.x, triangle.a.x, triangle.b.x, triangle.c.x );
this.bounds.min.y = Math.min( this.bounds.min.y, triangle.a.y, triangle.b.y, triangle.c.y );
this.bounds.min.z = Math.min( this.bounds.min.z, triangle.a.z, triangle.b.z, triangle.c.z );
this.bounds.max.x = Math.max( this.bounds.max.x, triangle.a.x, triangle.b.x, triangle.c.x );
this.bounds.max.y = Math.max( this.bounds.max.y, triangle.a.y, triangle.b.y, triangle.c.y );
this.bounds.max.z = Math.max( this.bounds.max.z, triangle.a.z, triangle.b.z, triangle.c.z );
this.triangles.push( triangle );
return this;
}
calcBox() {
this.box = this.bounds.clone();
// offset small ammount to account for regular grid
this.box.min.x -= 0.01;
this.box.min.y -= 0.01;
this.box.min.z -= 0.01;
return this;
}
split( level ) {
if ( ! this.box ) return;
const subTrees = [];
const halfsize = _v2.copy( this.box.max ).sub( this.box.min ).multiplyScalar( 0.5 );
for ( let x = 0; x < 2; x ++ ) {
for ( let y = 0; y < 2; y ++ ) {
for ( let z = 0; z < 2; z ++ ) {
const box = new Box3();
const v = _v1.set( x, y, z );
box.min.copy( this.box.min ).add( v.multiply( halfsize ) );
box.max.copy( box.min ).add( halfsize );
subTrees.push( new Octree( box ) );
}
}
}
let triangle;
while ( triangle = this.triangles.pop() ) {
for ( let i = 0; i < subTrees.length; i ++ ) {
if ( subTrees[ i ].box.intersectsTriangle( triangle ) ) {
subTrees[ i ].triangles.push( triangle );
}
}
}
for ( let i = 0; i < subTrees.length; i ++ ) {
const len = subTrees[ i ].triangles.length;
if ( len > 8 && level < 16 ) {
subTrees[ i ].split( level + 1 );
}
if ( len !== 0 ) {
this.subTrees.push( subTrees[ i ] );
}
}
return this;
}
build() {
this.calcBox();
this.split( 0 );
return this;
}
getRayTriangles( ray, triangles ) {
for ( let i = 0; i < this.subTrees.length; i ++ ) {
const subTree = this.subTrees[ i ];
if ( ! ray.intersectsBox( subTree.box ) ) continue;
if ( subTree.triangles.length > 0 ) {
for ( let j = 0; j < subTree.triangles.length; j ++ ) {
if ( triangles.indexOf( subTree.triangles[ j ] ) === - 1 ) triangles.push( subTree.triangles[ j ] );
}
} else {
subTree.getRayTriangles( ray, triangles );
}
}
return triangles;
}
triangleCapsuleIntersect( capsule, triangle ) {
triangle.getPlane( _plane );
const d1 = _plane.distanceToPoint( capsule.start ) - capsule.radius;
const d2 = _plane.distanceToPoint( capsule.end ) - capsule.radius;
if ( ( d1 > 0 && d2 > 0 ) || ( d1 < - capsule.radius && d2 < - capsule.radius ) ) {
return false;
}
const delta = Math.abs( d1 / ( Math.abs( d1 ) + Math.abs( d2 ) ) );
const intersectPoint = _v1.copy( capsule.start ).lerp( capsule.end, delta );
if ( triangle.containsPoint( intersectPoint ) ) {
return { normal: _plane.normal.clone(), point: intersectPoint.clone(), depth: Math.abs( Math.min( d1, d2 ) ) };
}
const r2 = capsule.radius * capsule.radius;
const line1 = _line1.set( capsule.start, capsule.end );
const lines = [
[ triangle.a, triangle.b ],
[ triangle.b, triangle.c ],
[ triangle.c, triangle.a ]
];
for ( let i = 0; i < lines.length; i ++ ) {
const line2 = _line2.set( lines[ i ][ 0 ], lines[ i ][ 1 ] );
const [ point1, point2 ] = capsule.lineLineMinimumPoints( line1, line2 );
if ( point1.distanceToSquared( point2 ) < r2 ) {
return { normal: point1.clone().sub( point2 ).normalize(), point: point2.clone(), depth: capsule.radius - point1.distanceTo( point2 ) };
}
}
return false;
}
triangleSphereIntersect( sphere, triangle ) {
triangle.getPlane( _plane );
if ( ! sphere.intersectsPlane( _plane ) ) return false;
const depth = Math.abs( _plane.distanceToSphere( sphere ) );
const r2 = sphere.radius * sphere.radius - depth * depth;
const plainPoint = _plane.projectPoint( sphere.center, _v1 );
if ( triangle.containsPoint( sphere.center ) ) {
return { normal: _plane.normal.clone(), point: plainPoint.clone(), depth: Math.abs( _plane.distanceToSphere( sphere ) ) };
}
const lines = [
[ triangle.a, triangle.b ],
[ triangle.b, triangle.c ],
[ triangle.c, triangle.a ]
];
for ( let i = 0; i < lines.length; i ++ ) {
_line1.set( lines[ i ][ 0 ], lines[ i ][ 1 ] );
_line1.closestPointToPoint( plainPoint, true, _v2 );
const d = _v2.distanceToSquared( sphere.center );
if ( d < r2 ) {
return { normal: sphere.center.clone().sub( _v2 ).normalize(), point: _v2.clone(), depth: sphere.radius - Math.sqrt( d ) };
}
}
return false;
}
getSphereTriangles( sphere, triangles ) {
for ( let i = 0; i < this.subTrees.length; i ++ ) {
const subTree = this.subTrees[ i ];
if ( ! sphere.intersectsBox( subTree.box ) ) continue;
if ( subTree.triangles.length > 0 ) {
for ( let j = 0; j < subTree.triangles.length; j ++ ) {
if ( triangles.indexOf( subTree.triangles[ j ] ) === - 1 ) triangles.push( subTree.triangles[ j ] );
}
} else {
subTree.getSphereTriangles( sphere, triangles );
}
}
}
getCapsuleTriangles( capsule, triangles ) {
for ( let i = 0; i < this.subTrees.length; i ++ ) {
const subTree = this.subTrees[ i ];
if ( ! capsule.intersectsBox( subTree.box ) ) continue;
if ( subTree.triangles.length > 0 ) {
for ( let j = 0; j < subTree.triangles.length; j ++ ) {
if ( triangles.indexOf( subTree.triangles[ j ] ) === - 1 ) triangles.push( subTree.triangles[ j ] );
}
} else {
subTree.getCapsuleTriangles( capsule, triangles );
}
}
}
sphereIntersect( sphere ) {
_sphere.copy( sphere );
const triangles = [];
let result, hit = false;
this.getSphereTriangles( sphere, triangles );
for ( let i = 0; i < triangles.length; i ++ ) {
if ( result = this.triangleSphereIntersect( _sphere, triangles[ i ] ) ) {
hit = true;
_sphere.center.add( result.normal.multiplyScalar( result.depth ) );
}
}
if ( hit ) {
const collisionVector = _sphere.center.clone().sub( sphere.center );
const depth = collisionVector.length();
return { normal: collisionVector.normalize(), depth: depth };
}
return false;
}
capsuleIntersect( capsule ) {
_capsule.copy( capsule );
const triangles = [];
let result, hit = false;
this.getCapsuleTriangles( _capsule, triangles );
for ( let i = 0; i < triangles.length; i ++ ) {
if ( result = this.triangleCapsuleIntersect( _capsule, triangles[ i ] ) ) {
hit = true;
_capsule.translate( result.normal.multiplyScalar( result.depth ) );
}
}
if ( hit ) {
const collisionVector = _capsule.getCenter( new Vector3() ).sub( capsule.getCenter( _v1 ) );
const depth = collisionVector.length();
return { normal: collisionVector.normalize(), depth: depth };
}
return false;
}
rayIntersect( ray ) {
if ( ray.direction.length() === 0 ) return;
const triangles = [];
let triangle, position, distance = 1e100;
this.getRayTriangles( ray, triangles );
for ( let i = 0; i < triangles.length; i ++ ) {
const result = ray.intersectTriangle( triangles[ i ].a, triangles[ i ].b, triangles[ i ].c, true, _v1 );
if ( result ) {
const newdistance = result.sub( ray.origin ).length();
if ( distance > newdistance ) {
position = result.clone().add( ray.origin );
distance = newdistance;
triangle = triangles[ i ];
}
}
}
return distance < 1e100 ? { distance: distance, triangle: triangle, position: position } : false;
}
fromGraphNode( group ) {
group.updateWorldMatrix( true, true );
group.traverse( ( obj ) => {
if ( obj.isMesh === true ) {
let geometry, isTemp = false;
if ( obj.geometry.index !== null ) {
isTemp = true;
geometry = obj.geometry.toNonIndexed();
} else {
geometry = obj.geometry;
}
const positionAttribute = geometry.getAttribute( 'position' );
for ( let i = 0; i < positionAttribute.count; i += 3 ) {
const v1 = new Vector3().fromBufferAttribute( positionAttribute, i );
const v2 = new Vector3().fromBufferAttribute( positionAttribute, i + 1 );
const v3 = new Vector3().fromBufferAttribute( positionAttribute, i + 2 );
v1.applyMatrix4( obj.matrixWorld );
v2.applyMatrix4( obj.matrixWorld );
v3.applyMatrix4( obj.matrixWorld );
this.addTriangle( new Triangle( v1, v2, v3 ) );
}
if ( isTemp ) {
geometry.dispose();
}
}
} );
this.build();
return this;
}
}
export { Octree };