Question by charlesaverill20 · Apr 06, 2019 at 07:33 PM · collision rigidbody rigidbody.addforce forces disappearing

Object disappearing when it collides,Objects disappear on collision

Hello, I'm building a 3D particle simulator, and I've just recently added gravity. I have a loop that goes through all particles in the scene and applies a gravitational force to them that factors in their mass. I've been using Rigidbody's mass field as a way to input AMU (atomic mass units) so that I don't have to type in tons of zeros for the mass. Only recently did I add a method to convert from AMU to KG, and now that I have, the particles still attract correctly, but now they disappear upon collision, and I receive this error:

 rigidbody.force assign attempt for 'Particle (1)' is not valid. Input force is { NaN, NaN, NaN }.
 UnityEngine.Rigidbody:AddForce(Vector3, ForceMode)
 Gravity:Update() (at Assets/Gravity.cs:39)

Here's my gravity code:

  for (int i = 0; i < originalParticles.Length; i++)
  {
      Particle particle = originalParticles[i];
      for (int j = 0; j < originalParticles.Length; j++)
       {
            Particle secondParticle = originalParticles[j];
            if (i != j)
            {
                 float dist = Vector3.Distance(particle.transform.position, secondParticle.transform.position);
 
                 float magnitude = G * (particle.getMass() * secondParticle.getMass()) / (dist * dist);
 
                 Vector3 twoToOne = secondParticle.transform.position - particle.transform.position;
                 Vector3 oneToTwo = twoToOne.normalized * -magnitude;
 
                 finalParticles[i].rb.AddForce(twoToOne, ForceMode.Force);
                 finalParticles[j].rb.AddForce(oneToTwo, ForceMode.Force);
 
                 finalParticles[i].acceleration = oneToTwo / amuToKG(finalParticles[i].getMass());
                 finalParticles[j].acceleration = twoToOne / amuToKG(finalParticles[j].getMass());
             }
        }
   }

originalParticles and finalParticles just hold all particles in the scene, and math is applied on the final particles, but with the variables of the initial particles so that the gravity calculations are correct.

Thank you!

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