// Newton's third law of motion: for every action, there is an equal and opposite reaction
public static void ResolveCollision(Rigidbody a, Rigidbody b)
{
// Find the direction of collision, all changes only occur in this direction
Vector3 direction = a.Position - b.Position;
direction.Normalize();
// Determine the relative velocity in the direction of collision
// Use a dot product to get the "projection", then multiply by the direction
// Note the - sign since we are working with respect to a
Vector3 relativeVelocity = a.Velocity - b.Velocity;
Vector3 relativeVelocityPerp = -Vector3.Dot(relativeVelocity, direction) * direction;
// Finally the impulse Force acting on the object is given thus
// Formula = V_n / (m1 + m2) * m1m2 = V_n / (1/m1 + 1/m2)
// Note: system fails if m1 or m2 = 0; but we don't allow that (see Rigidbody)
Vector3 impulse = relativeVelocityPerp / ((1 / a.Mass) + (1 / b.Mass));
// Finally add the impulse to both objects (third law of motion)
// the 2 comes from (1 + e1e2) where e1 and e2 are the coefficients of restitution
a.Impulse += 2 * impulse;
b.Impulse -= 2 * impulse;
//float epsilon = (a.CoRestitution * b.CoRestitution);
//a.Impulse += (-(1 + epsilon) * (Vector3(collidingNormal)) / (a.Mass + b.Mass)) * (a.Mass * b.Mass) * impule;
//b.Impulse -= (-(1 + epsilon) * (Vector3(collidingNormal)) / (a.Mass + b.Mass)) * (a.Mass * b.Mass) * impulse;
// F = ((-(1 + e)*V_n)/(m1 + m2))*(m1*m2)
}
// checks if block did collide with sphere
public bool DidCollide(Rigidbody sphere)
{
// test for collision with each triangles on the cube
for (int i = 0; i < 12; i++)
{
Vector3 normal = normals[i / 2];
if (Physics.TestSphereTriangle(sphere, triangles[i]))
{
CurrentState = State.Moved;
OnBreakEvent();
//add physics to Block depending on BlockType?
switch (BlockType)
{
case Type.Glass:
break;
case Type.Wood:
break;
case Type.Stone:
break;
default:
break;
}
//Impulse = sphere.Velocity / 2.0f;
//Acceleration = new Vector3(0.0f, -9.81f, 0.0f);
return true;
}
}
return false;
}
