topical media & game development
mobile-query-three-plugins-ogsworkshop-examples-physicsr45-Collisions.js / js
author: bartek drozdz / everyday3d.com/
THREE.PlaneCollider = function( point, normal ) {
this.point = point;
this.normal = normal;
};
THREE.SphereCollider = function( center, radius ) {
this.center = center;
this.radius = radius;
this.radiusSq = radius * radius;
};
THREE.BoxCollider = function( min, max ) {
this.min = min;
this.max = max;
this.dynamic = true;
this.normal = new THREE.Vector3();
};
THREE.MeshCollider = function( mesh, box ) {
this.mesh = mesh;
this.box = box;
this.numFaces = this.mesh.geometry.faces.length;
this.normal = new THREE.Vector3();
};
THREE.CollisionSystem = function() {
this.collisionNormal = new THREE.Vector3();
this.colliders = [];
this.hits = [];
// console.log("Collision system init / 004");
};
THREE.Collisions = new THREE.CollisionSystem();
THREE.CollisionSystem.prototype.merge = function( collisionSystem ) {
Array.prototype.push.apply( this.colliders, collisionSystem.colliders );
Array.prototype.push.apply( this.hits, collisionSystem.hits );
};
THREE.CollisionSystem.prototype.rayCastAll = function( ray ) {
ray.direction.normalize();
this.hits.length = 0;
var i, l, d, collider,
ld = 0;
for ( i = 0, l = this.colliders.length; i < l; i++ ) {
collider = this.colliders[ i ];
d = this.rayCast( ray, collider );
if ( d < Number.MAX_VALUE ) {
collider.distance = d;
if ( d > ld )
this.hits.push( collider );
else
this.hits.unshift( collider );
ld = d;
}
}
return this.hits;
};
THREE.CollisionSystem.prototype.rayCastNearest = function( ray ) {
var cs = this.rayCastAll( ray );
if( cs.length == 0 ) return null;
var i = 0;
while( cs[ i ] instanceof THREE.MeshCollider ) {
var dist_index = this.rayMesh ( ray, cs[ i ] );
if( dist_index.dist < Number.MAX_VALUE ) {
cs[ i ].distance = dist_index.dist;
cs[ i ].faceIndex = dist_index.faceIndex;
break;
}
i++;
}
if ( i > cs.length ) return null;
return cs[ i ];
};
THREE.CollisionSystem.prototype.rayCast = function( ray, collider ) {
if ( collider instanceof THREE.PlaneCollider )
return this.rayPlane( ray, collider );
else if ( collider instanceof THREE.SphereCollider )
return this.raySphere( ray, collider );
else if ( collider instanceof THREE.BoxCollider )
return this.rayBox( ray, collider );
else if ( collider instanceof THREE.MeshCollider && collider.box )
return this.rayBox( ray, collider.box );
};
THREE.CollisionSystem.prototype.rayMesh = function( r, me ) {
var rt = this.makeRayLocal( r, me.mesh );
var d = Number.MAX_VALUE;
var nearestface;
for( var i = 0; i < me.numFaces; i++ ) {
var face = me.mesh.geometry.faces[i];
var p0 = me.mesh.geometry.vertices[ face.a ].position;
var p1 = me.mesh.geometry.vertices[ face.b ].position;
var p2 = me.mesh.geometry.vertices[ face.c ].position;
var p3 = face instanceof THREE.Face4 ? me.mesh.geometry.vertices[ face.d ].position : null;
if (face instanceof THREE.Face3) {
var nd = this.rayTriangle( rt, p0, p1, p2, d, this.collisionNormal, me.mesh );
if( nd < d ) {
d = nd;
nearestface = i;
me.normal.copy( this.collisionNormal );
me.normal.normalize();
}
}
else if (face instanceof THREE.Face4) {
var nd = this.rayTriangle( rt, p0, p1, p3, d, this.collisionNormal, me.mesh );
if( nd < d ) {
d = nd;
nearestface = i;
me.normal.copy( this.collisionNormal );
me.normal.normalize();
}
nd = this.rayTriangle( rt, p1, p2, p3, d, this.collisionNormal, me.mesh );
if( nd < d ) {
d = nd;
nearestface = i;
me.normal.copy( this.collisionNormal );
me.normal.normalize();
}
}
}
return {dist: d, faceIndex: nearestface};
};
THREE.CollisionSystem.prototype.rayTriangle = function( ray, p0, p1, p2, mind, n, mesh ) {
var e1 = THREE.CollisionSystem.__v1,
e2 = THREE.CollisionSystem.__v2;
n.set( 0, 0, 0 );
// do not crash on quads, fail instead
e1.sub( p1, p0 );
e2.sub( p2, p1 );
n.cross( e1, e2 )
var dot = n.dot( ray.direction );
if ( !( dot < 0 ) ) {
if ( mesh.doubleSided || mesh.flipSided ) {
n.multiplyScalar (-1.0);
dot *= -1.0;
} else {
return Number.MAX_VALUE;
}
}
var d = n.dot( p0 );
var t = d - n.dot( ray.origin );
if ( !( t <= 0 ) ) return Number.MAX_VALUE;
if ( !( t >= dot * mind ) ) return Number.MAX_VALUE;
t = t / dot;
var p = THREE.CollisionSystem.__v3;
p.copy( ray.direction );
p.multiplyScalar( t );
p.addSelf( ray.origin );
var u0, u1, u2, v0, v1, v2;
if ( Math.abs( n.x ) > Math.abs( n.y ) ) {
if ( Math.abs( n.x ) > Math.abs( n.z ) ) {
u0 = p.y - p0.y;
u1 = p1.y - p0.y;
u2 = p2.y - p0.y;
v0 = p.z - p0.z;
v1 = p1.z - p0.z;
v2 = p2.z - p0.z;
} else {
u0 = p.x - p0.x;
u1 = p1.x - p0.x;
u2 = p2.x - p0.x;
v0 = p.y - p0.y;
v1 = p1.y - p0.y;
v2 = p2.y - p0.y;
}
} else {
if( Math.abs( n.y ) > Math.abs( n.z ) ) {
u0 = p.x - p0.x;
u1 = p1.x - p0.x;
u2 = p2.x - p0.x;
v0 = p.z - p0.z;
v1 = p1.z - p0.z;
v2 = p2.z - p0.z;
} else {
u0 = p.x - p0.x;
u1 = p1.x - p0.x;
u2 = p2.x - p0.x;
v0 = p.y - p0.y;
v1 = p1.y - p0.y;
v2 = p2.y - p0.y;
}
}
var temp = u1 * v2 - v1 * u2;
if( !(temp != 0) ) return Number.MAX_VALUE;
//console.log("temp: " + temp);
temp = 1 / temp;
var alpha = ( u0 * v2 - v0 * u2 ) * temp;
if( !(alpha >= 0) ) return Number.MAX_VALUE;
//console.log("alpha: " + alpha);
var beta = ( u1 * v0 - v1 * u0 ) * temp;
if( !(beta >= 0) ) return Number.MAX_VALUE;
//console.log("beta: " + beta);
var gamma = 1 - alpha - beta;
if( !(gamma >= 0) ) return Number.MAX_VALUE;
//console.log("gamma: " + gamma);
return t;
};
THREE.CollisionSystem.prototype.makeRayLocal = function( ray, m ) {
var mt = THREE.CollisionSystem.__m;
THREE.Matrix4.makeInvert( m.matrixWorld, mt );
var rt = THREE.CollisionSystem.__r;
rt.origin.copy( ray.origin );
rt.direction.copy( ray.direction );
mt.multiplyVector3( rt.origin );
mt.rotateAxis( rt.direction );
rt.direction.normalize();
//m.localRay = rt;
return rt;
};
THREE.CollisionSystem.prototype.rayBox = function( ray, ab ) {
var rt;
if ( ab.dynamic && ab.mesh && ab.mesh.matrixWorld ) {
rt = this.makeRayLocal( ray, ab.mesh );
} else {
rt = THREE.CollisionSystem.__r;
rt.origin.copy( ray.origin );
rt.direction.copy( ray.direction );
}
var xt = 0, yt = 0, zt = 0;
var xn = 0, yn = 0, zn = 0;
var ins = true;
if( rt.origin.x < ab.min.x ) {
xt = ab.min.x - rt.origin.x;
//if(xt > ray.direction.x) return return Number.MAX_VALUE;
xt /= rt.direction.x;
ins = false;
xn = -1;
} else if( rt.origin.x > ab.max.x ) {
xt = ab.max.x - rt.origin.x;
//if(xt < ray.direction.x) return return Number.MAX_VALUE;
xt /= rt.direction.x;
ins = false;
xn = 1;
}
if( rt.origin.y < ab.min.y ) {
yt = ab.min.y - rt.origin.y;
//if(yt > ray.direction.y) return return Number.MAX_VALUE;
yt /= rt.direction.y;
ins = false;
yn = -1;
} else if( rt.origin.y > ab.max.y ) {
yt = ab.max.y - rt.origin.y;
//if(yt < ray.direction.y) return return Number.MAX_VALUE;
yt /= rt.direction.y;
ins = false;
yn = 1;
}
if( rt.origin.z < ab.min.z ) {
zt = ab.min.z - rt.origin.z;
//if(zt > ray.direction.z) return return Number.MAX_VALUE;
zt /= rt.direction.z;
ins = false;
zn = -1;
} else if( rt.origin.z > ab.max.z ) {
zt = ab.max.z - rt.origin.z;
//if(zt < ray.direction.z) return return Number.MAX_VALUE;
zt /= rt.direction.z;
ins = false;
zn = 1;
}
if( ins ) return -1;
var which = 0;
var t = xt;
if( yt > t ) {
which = 1;
t = yt;
}
if ( zt > t ) {
which = 2;
t = zt;
}
switch( which ) {
case 0:
var y = rt.origin.y + rt.direction.y * t;
if ( y < ab.min.y || y > ab.max.y ) return Number.MAX_VALUE;
var z = rt.origin.z + rt.direction.z * t;
if ( z < ab.min.z || z > ab.max.z ) return Number.MAX_VALUE;
ab.normal.set( xn, 0, 0 );
break;
case 1:
var x = rt.origin.x + rt.direction.x * t;
if ( x < ab.min.x || x > ab.max.x ) return Number.MAX_VALUE;
var z = rt.origin.z + rt.direction.z * t;
if ( z < ab.min.z || z > ab.max.z ) return Number.MAX_VALUE;
ab.normal.set( 0, yn, 0) ;
break;
case 2:
var x = rt.origin.x + rt.direction.x * t;
if ( x < ab.min.x || x > ab.max.x ) return Number.MAX_VALUE;
var y = rt.origin.y + rt.direction.y * t;
if ( y < ab.min.y || y > ab.max.y ) return Number.MAX_VALUE;
ab.normal.set( 0, 0, zn );
break;
}
return t;
};
THREE.CollisionSystem.prototype.rayPlane = function( r, p ) {
var t = r.direction.dot( p.normal );
var d = p.point.dot( p.normal );
var ds;
if( t < 0 ) ds = ( d - r.origin.dot( p.normal ) ) / t;
else return Number.MAX_VALUE;
if( ds > 0 ) return ds;
else return Number.MAX_VALUE;
};
THREE.CollisionSystem.prototype.raySphere = function( r, s ) {
var e = s.center.clone().subSelf( r.origin );
if ( e.lengthSq < s.radiusSq ) return -1;
var a = e.dot( r.direction.clone() );
if ( a <= 0 ) return Number.MAX_VALUE;
var t = s.radiusSq - ( e.lengthSq() - a * a );
if ( t >= 0 ) return Math.abs( a ) - Math.sqrt( t );
return Number.MAX_VALUE;
};
THREE.CollisionSystem.__v1 = new THREE.Vector3();
THREE.CollisionSystem.__v2 = new THREE.Vector3();
THREE.CollisionSystem.__v3 = new THREE.Vector3();
THREE.CollisionSystem.__nr = new THREE.Vector3();
THREE.CollisionSystem.__m = new THREE.Matrix4();
THREE.CollisionSystem.__r = new THREE.Ray();
(C) Æliens
04/09/2009
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