// SEPARATION: Steering to avoid colliding or crowing with other flockmates
private Vector3 CalculateSeparation(int boidIndex)
{
ComputeBoid boid = m_boids[boidIndex];
if (boid.GetNeighbourCount() == 0)
{
return(Vector3.zero);
}
Vector3 separationForce = Vector3.zero;
Vector3 boidPosition = boid.transform.position;
float separationDistSqr = m_separationValue * m_separationValue;
foreach (ComputeBoid neighbour in boid.IterateNeighbours())
{
Vector3 difference = boidPosition - neighbour.transform.position;
float distanceSqr = difference.sqrMagnitude;
if (distanceSqr < separationDistSqr)
{
// Needs separating
Vector3 separate = difference;
separate.Normalize();
separate = separate / distanceSqr;
separationForce += separate;
}
}
return(separationForce);
}
// ALIGNMENT: Steering to move with the average heading of flockmates
private Vector3 CalculateAlignment(int boidIndex)
{
ComputeBoid boid = m_boids[boidIndex];
if (boid.GetNeighbourCount() == 0)
{
return(Vector3.zero);
}
Vector3 alignmentForce = Vector3.zero;
Vector3 sumHeading = Vector3.zero;
foreach (ComputeBoid neighbour in boid.IterateNeighbours())
{
sumHeading = neighbour.GetBoidVelocity().normalized;
}
alignmentForce = sumHeading / boid.GetNeighbourCount();
return(alignmentForce);
}
private void CalculateRules(int boidIndex, ref Vector3 sepForce, ref Vector3 alignForce, ref Vector3 cohForce)
{
ComputeBoid boid = m_boids[boidIndex];
if (boid.GetNeighbourCount() == 0)
{
return;
}
Vector3 boidPosition = boid.transform.position;
sepForce = Vector3.zero;
alignForce = Vector3.zero;
cohForce = Vector3.zero;
float separationDistSqr = m_separationValue * m_separationValue;
Vector3 sumHeading = Vector3.zero;
Vector3 averagePosition = Vector3.zero;
foreach (ComputeBoid neighbour in boid.IterateNeighbours())
{
sumHeading = neighbour.GetBoidVelocity().normalized;
averagePosition += neighbour.transform.position;
Vector3 difference = boidPosition - neighbour.transform.position;
float distanceSqr = difference.sqrMagnitude;
if (distanceSqr < separationDistSqr)
{
// Needs separating
Vector3 separate = difference;
separate.Normalize();
separate = separate / distanceSqr;
sepForce += separate;
}
}
alignForce = sumHeading / boid.GetNeighbourCount();
averagePosition /= boid.GetNeighbourCount();
cohForce = averagePosition - m_boids[boidIndex].transform.position;
}
// COHESION: Steering to move towards the average position of flockmates
private Vector3 CalculateCohesion(int boidIndex)
{
ComputeBoid boid = m_boids[boidIndex];
if (boid.GetNeighbourCount() == 0)
{
return(Vector3.zero);
}
Vector3 cohesionForce = Vector3.zero;
Vector3 averagePosition = Vector3.zero;
foreach (ComputeBoid neighbour in boid.IterateNeighbours())
{
averagePosition += neighbour.transform.position;
}
averagePosition /= boid.GetNeighbourCount();
cohesionForce = averagePosition - m_boids[boidIndex].transform.position;
return(cohesionForce);
}
public void AddNeighbour(ComputeBoid neighbour)
{
m_neighbours.Add(neighbour);
}
void FixedUpdate()
{
// Find boids neighbours
PerformNeighbourSearch();
if (!m_updatePosition)
{
return;
}
for (int i = 0; i < m_boids.Length; ++i)
{
ComputeBoid boid = m_boids[i];
Vector3 newVelocity = Vector3.zero;
Vector3 separation = Vector3.zero;
Vector3 alignment = Vector3.zero;
Vector3 cohesion = Vector3.zero;
CalculateRules(i, ref separation, ref alignment, ref cohesion);
// 1) SEPARATION
if (m_enableSeparation)
{
//separation = CalculateSeparation( i );
if (m_drawSeparationDebugRays &&
separation.sqrMagnitude > 0.0f)
{
DrawRedRay(boid, separation);
}
newVelocity += separation * m_separationFactor;
}
// 2) ALIGNMENT
if (m_enableAlignment)
{
//alignment = CalculateAlignment( i );
if (m_drawAlignmentDebugRays &&
alignment.sqrMagnitude > 0.0f)
{
DrawRay(boid, alignment, Color.blue);
}
newVelocity += alignment * m_alignmentFactor;
}
// 3) COHESION
if (m_enableCohesion)
{
//cohesion = CalculateCohesion( i );
if (m_drawCohesionDebugRays &&
cohesion.sqrMagnitude > 0.0f)
{
DrawRay(boid, cohesion, Color.green);
}
newVelocity += cohesion * m_cohesionFactor;
}
if (m_drawBoidAxis)
{
boid.DrawDebugAxis();
}
boid.SetBoidVelocity(newVelocity);
boid.UpdatePosition();
boid.ClearNeighbours();
}
}
private void DrawRay(ComputeBoid boid, Vector3 direction, Color colour)
{
Debug.DrawRay(boid.transform.position, direction, colour);
}
private void DrawRedRay(ComputeBoid boid, Vector3 direction)
{
DrawRay(boid, direction, Color.red);
}