private void FixedUpdate()
{
foreach (Tuple <PotentialBase, RigidTripletType> pot_rigids_pair in m_PotentialRigidbodiesPairs)
{
PotentialBase potential = pot_rigids_pair.Item1;
RigidTripletType rigid_triplet = pot_rigids_pair.Item2;
Rigidbody rigid_i = rigid_triplet.Item1;
Rigidbody rigid_j = rigid_triplet.Item2;
Rigidbody rigid_k = rigid_triplet.Item3;
Vector3 r_ji = rigid_i.position - rigid_j.position;
Vector3 r_jk = rigid_k.position - rigid_j.position;
Vector3 e_ji = r_ji.normalized;
Vector3 e_jk = r_jk.normalized;
float cos_theta = Vector3.Dot(e_ji, e_jk);
float theta = Mathf.Acos(cos_theta);
float sin_theta = Mathf.Sin(theta);
float inv_sin_r_ji_len = 1.0f / (sin_theta * r_ji.magnitude);
float inv_sin_r_jk_len = 1.0f / (sin_theta * r_jk.magnitude);
float coef = potential.Derivative(theta);
Vector3 Fi = -coef * inv_sin_r_ji_len * (cos_theta * e_ji - e_jk);
Vector3 Fk = -coef * inv_sin_r_jk_len * (cos_theta * e_jk - e_ji);
rigid_i.AddForce(Fi);
rigid_k.AddForce(Fk);
rigid_j.AddForce(-(Fi + Fk));
}
}
internal void Init(List <Tuple <PotentialBase, RigidTripletType> > pot_rigids_pairs)
{
enabled = true;
m_PotentialRigidbodiesPairs = pot_rigids_pairs;
// setting ignore collision
foreach (Tuple <PotentialBase, RigidTripletType> pot_rigids_pair in m_PotentialRigidbodiesPairs)
{
RigidTripletType rigid_triplet = pot_rigids_pair.Item2;
Collider collider_i = rigid_triplet.Item1.GetComponent <Collider>();
Collider collider_k = rigid_triplet.Item3.GetComponent <Collider>();
Physics.IgnoreCollision(collider_i, collider_k);
}
}
// This method generate InteractionManager for local of SceneBuilder by side effect.
internal void GenerateLocalInteractionManagers(
GameObject scene_builder, List <GameObject> base_particles, float timescale)
{
List <TomlTable> local_ffs = ForceFieldTable.Get <List <TomlTable> >("local");
foreach (TomlTable local_ff in local_ffs)
{
string interaction = local_ff.Get <string>("interaction");
string potential_str = local_ff.Get <string>("potential");
if (interaction == "BondLength")
{
var parameters = local_ff.Get <List <TomlTable> >("parameters");
var pot_rigids_pairs = new List <Tuple <PotentialBase, RigidPairType> >();
if (potential_str == "Harmonic")
{
foreach (TomlTable parameter in parameters)
{
var v0 = parameter.Get <float>("v0");
var k = parameter.Get <float>("k");
var potential = new HarmonicPotential(v0, k, timescale);
List <int> indices = parameter.Get <List <int> >("indices");
Assert.AreEqual(indices.Count, 2,
"The length of indices must be 2.");
var rigid1 = base_particles[indices[0]].GetComponent <Rigidbody>();
var rigid2 = base_particles[indices[1]].GetComponent <Rigidbody>();
var rigid_pair = new RigidPairType(rigid1, rigid2);
pot_rigids_pairs.Add(new Tuple <PotentialBase, RigidPairType>(potential, rigid_pair));
}
}
else if (potential_str == "GoContact")
{
foreach (TomlTable parameter in parameters)
{
var v0 = parameter.Get <float>("v0");
var k = parameter.Get <float>("k");
var potential = new GoContactPotential(v0, k, timescale);
List <int> indices = parameter.Get <List <int> >("indices");
Assert.AreEqual(indices.Count, 2,
"The length of indices must be 2.");
var rigid1 = base_particles[indices[0]].GetComponent <Rigidbody>();
var rigid2 = base_particles[indices[1]].GetComponent <Rigidbody>();
var rigid_pair = new RigidPairType(rigid1, rigid2);
pot_rigids_pairs.Add(new Tuple <PotentialBase, RigidPairType>(potential, rigid_pair));
}
}
BondLengthInteractionManager bli_manager
= scene_builder.AddComponent <BondLengthInteractionManager>() as BondLengthInteractionManager;
bli_manager.Init(pot_rigids_pairs);
string potential_name = bli_manager.PotentialName();
Debug.Log($"BondLengthInteraction with {potential_name} initialization finished.");
}
else if (interaction == "BondAngle")
{
var parameters = local_ff.Get <List <TomlTable> >("parameters");
var pot_rigids_pairs = new List <Tuple <PotentialBase, RigidTripletType> >();
if (potential_str == "Harmonic")
{
foreach (TomlTable parameter in parameters)
{
var v0 = parameter.Get <float>("v0");
var k = parameter.Get <float>("k");
var potential = new HarmonicPotential(v0, k, timescale);
List <int> indices = parameter.Get <List <int> >("indices");
Assert.AreEqual(indices.Count, 3,
"The length of indices must be 3.");
var rigid_i = base_particles[indices[0]].GetComponent <Rigidbody>();
var rigid_j = base_particles[indices[1]].GetComponent <Rigidbody>();
var rigid_k = base_particles[indices[2]].GetComponent <Rigidbody>();
var rigid_triplets = new RigidTripletType(rigid_i, rigid_j, rigid_k);
pot_rigids_pairs.Add(new Tuple <PotentialBase, RigidTripletType>(potential, rigid_triplets));
}
}
BondAngleInteractionManager bai_manager =
scene_builder.AddComponent <BondAngleInteractionManager>() as BondAngleInteractionManager;
bai_manager.Init(pot_rigids_pairs);
string potential_name = bai_manager.PotentialName();
Debug.Log($"BondAngleInteraciton with {potential_name} initialization finished.");
}
else if (interaction == "DihedralAngle")
{
var parameters = local_ff.Get <List <TomlTable> >("parameters");
var pot_rigids_pairs = new List <Tuple <PotentialBase, RigidQuadrupletType> >();
if (potential_str == "ClementiDihedral")
{
foreach (TomlTable parameter in parameters)
{
var v0 = parameter.Get <float>("v0");
var k1 = parameter.Get <float>("k1");
var k3 = parameter.Get <float>("k3");
var potential = new ClementiDihedralPotential(v0, k1, k3, timescale);
List <int> indices = parameter.Get <List <int> >("indices");
Assert.AreEqual(indices.Count, 4,
"The length of indices must be 4.");
var rigid_i = base_particles[indices[0]].GetComponent <Rigidbody>();
var rigid_j = base_particles[indices[1]].GetComponent <Rigidbody>();
var rigid_k = base_particles[indices[2]].GetComponent <Rigidbody>();
var rigid_l = base_particles[indices[3]].GetComponent <Rigidbody>();
var rigid_quadruplet = new RigidQuadrupletType(rigid_i, rigid_j, rigid_k, rigid_l);
pot_rigids_pairs.Add(
new Tuple <PotentialBase, RigidQuadrupletType>(potential, rigid_quadruplet));
}
}
DihedralAngleInteractionManager dai_manager =
scene_builder.AddComponent <DihedralAngleInteractionManager>() as DihedralAngleInteractionManager;
dai_manager.Init(pot_rigids_pairs);
string potential_name = dai_manager.PotentialName();
Debug.Log($"DihedralAngleInteraction with {potential_name} initialization finished");
}
else
{
Debug.LogWarning($@"
Unknown combination of local interaction {interaction} and forcefields {potential_str} is specified.
This table will be ignored.
Available combination is
- Interaction: BondLength, Potential: Harmonic
- Interaction: BondLength, Potential: GoContact
- Interaction: BondAngle, Potential: Harmonic
- Interaction: DihedralAngle, Potential: ClementiDihedral");
}
}
}
