1

我正在尝试在我的 3D 环境中进行一些简单的重力处理（我正在使用three.js）。我有一些代码，但它不起作用。我希望它只是某个地方的一个愚蠢的错误。编辑：替换旧代码

function handleGravity() {
    for(var j = 0; j < spheres.length; j++) {

        for(var i = 0; i < spheres.length; i++) {

            var r1 = new Array( spheres[j].position.x, spheres[j].position.y, spheres[j].position.z);
            var r2 = new Array( spheres[i].position.x, spheres[i].position.y, spheres[i].position.z);
            var r12 = new Array(r2[0]-r1[0], r2[1]-r1[1], r2[2]-r1[2]);
            var r12UnitVector = new Array( r12[0]/Math.abs(r12[0]), r12[1]/Math.abs(r12[1]),r12[2]/Math.abs(r12[2]) );

            var m1 = masses[j];
            var m2 = masses[i];
            var r12Squared = r12[0]*r12[0] + r12[1]*r12[1] + r12[2]*r12[2];
            var a12 = new Array( -(gravConst*m2/r12Squared)*r12UnitVector[0], -(gravConst*m2/r12Squared)*r12UnitVector[1], -(gravConst*m2/r12Squared)*r12UnitVector[2]);

            velocities[j][0] += a12[0]*timePassed;
            velocities[j][1] += a12[1]*timePassed;
            velocities[j][2] += a12[2]*timePassed;
        }

    }
}

如果你发现它有什么问题，或者给我任何关于使用 JavaScript 在 3D 环境中最有效地模拟许多粒子的提示（我对物理 + 模拟非常陌生），那将是很棒的！

4

1 回答 1

0

这似乎有效：

function handleGravity() {
    for(var j = 0; j < spheres.length; j++) {

        for(var i = 0; i < spheres.length; i++) {
            if(i != j) {
                var r1 = new Array( spheres[j].position.x, spheres[j].position.y, spheres[j].position.z);
                var r2 = new Array( spheres[i].position.x, spheres[i].position.y, spheres[i].position.z);
                var r12 = new Array(r2[0]-r1[0], r2[1]-r1[1], r2[2]-r1[2]);
                var r12UnitVector = new Array( r12[0]/Math.abs(r12[0] + r12[1] + r12[2])/3, r12[1]/Math.abs(r12[0] + r12[1] + r12[2])/3, r12[2]/Math.abs(r12[0] + r12[1] + r12[2])/3 );

                var m1 = masses[j];
                var m2 = masses[i];
                var r12Squared = r12[0]*r12[0] + r12[1]*r12[1] + r12[2]*r12[2];
                var a12 = new Array( -(gravConst*m2/r12Squared)*r12UnitVector[0], -(gravConst*m2/r12Squared)*r12UnitVector[1], -(gravConst*m2/r12Squared)*r12UnitVector[2]);

                velocities[j][0] -= a12[0]*timePassed;
                velocities[j][1] -= a12[1]*timePassed;
                velocities[j][2] -= a12[2]*timePassed;
            }
        }

    }
}
于 2013-04-01T12:45:08.263 回答