如何找到 2 个碰撞刚体的速度？

Question

所以我要进入物理引擎。现在的碰撞器是球体和平面。我发现碰撞的深度和接触点的法线很容易，但对于我来说，我无法完全理解能量的分布。

Body 包含一个 Collider、一个 Mass、一个力矢量（速度 * 质量）、一个弹性值（0 无反弹，1 完全反弹）和一个摩擦值（0 滑香肠，1 动量吸血鬼）I'我用谷歌搜索来回搜索，一切都得到了 1D 和 2D 的简化，但我一直无法将它们适应 3D。

编辑： 我试着关注这个页面： http://www.plasmaphysics.org.uk/collision3d.htm。看起来很简单，但不知为什么，弹性为1的我还是没有反弹。

我的实现如下：

var v = new vec3(
    (body.force.x + other.force.x) / totalMass,
    (body.force.y + other.force.y) / totalMass,
    (body.force.z + other.force.z) / totalMass
    );
body.force.set(
    ((velA.x - v.x) * elasticity + v.x) * body.mass,
    ((velA.y - v.y) * elasticity + v.y) * body.mass,
    ((velA.z - v.z) * elasticity + v.z) * body.mass
    );
other.force.set(
    ((velB.x - v.x) * elasticity + v.x) * other.mass,
    ((velB.y - v.y) * elasticity + v.y) * other.mass,
    ((velB.z - v.z) * elasticity + v.z) * other.mass
    );

对于弹性，我尝试了将两个物体的弹性相乘并求出它们的平均值；没有变化。

Answer 1

所以睡了一夜，从 N+ 物理解释页面获得了一些思考和巨大的帮助, 但我已经尽我所能评论了。

    //we have detected a collision between A) body B) other
        //note: for the sake of making things easier to think about,
        //      anything moving into or along the collision normal is
        //      referred to as vertical, anything perpendicular to
        //      the collision normal, is referred to as horizontal.
    //minimum translation required to resolve the collision
var mta = collision.normal.clone().multiplyScalar(collision.length);
    //the total mass involved in the collision
var totalMass = body.mass + other.mass;
    //the ratio of the mass belonging to body
var ratioA = body.mass / totalMass;
    //the ratio of the mass belonging to other
var ratioB = other.mass / totalMass;
    //the average elasticity of the collision
var elasticity = (body.elasticity + other.elasticity) / 2.0;
    //the friction of the collision
        //note: average works, but low values have strong effects,
        //      it is easier to work with if they are multiplied
var friction = body.friction * other.friction;
    //the vertical force of body
var vertA = -body.force.clone().normalize().dot(collision.normal);
    //the horizontal force of body
var horrA = 1.0 - Math.abs(vertA);
    //the vertical force of other
var vertB = -other.force.clone().normalize().dot(collision.normal);
    //the horizontal force of other
var horrB = 1.0 - Math.abs(vertB);
    //the amount of force applied on body
var forceA = body.force.length();
    //the amount of force applied on other
var forceB = other.force.length();
    //the amount of vertical force applied on body
var vForceA = forceA * vertA;
    //the amount of vertical force applied on other
var vForceB = forceB * vertB;
    //the amount of horizontal force applied on body
var hForceA = forceA * horrA;
    //the amount of horizontal force applied on other
var hForceB = forceB * horrB;
    //the total vertical force of the collision
var verticalForce = (vForceA + vForceB) * elasticity;
    //remove all vertical force from body
    //resulting in a horizontal force vector
body.force.add(collision.normal.clone().multiplyScalar(forceA * vertA));
    //apply friction to the horizontal force vector of body
body.force.add(body.force.clone().normalize().multiplyScalar(-friction * hForceA * body.imass));
    //apply the new vertical force to body
body.force.add(collision.normal.clone().multiplyScalar(verticalForce * ratioA));
    //remove all vertical force from other
    //resulting in a horizontal force vector
other.force.add(collision.normal.clone().multiplyScalar(-forceB * vertB));
    //apply friction to the horizontal force vector of other
other.force.add(other.force.clone().normalize().multiplyScalar(-friction * hForceB * other.imass));
    //apply the new vertical force to other
other.force.add(collision.normal.clone().multiplyScalar(-verticalForce * ratioB));
    //resolve collision taking into consideration mass
body.transform.position.sub(mta.clone().multiplyScalar(ratioA));
other.transform.position.add(mta.clone().multiplyScalar(ratioB));

如何找到 2 个碰撞刚体的速度？

How to find the velocity of 2 colliding rigid bodies?

physics

rigid-bodies

elasticity