void FixedUpdate () {
// Create particles
if( createIt < createItMax ){
// Create random
for(int i=0;i<createObjects/createItMax;i++){
GameObject g = Instantiate( PhysicsObjPrefab );
g.transform.position = new Vector3( Random.Range( -worldDimension.x/2f, worldDimension.x/2f ), worldDimension.y/2f, 0 );
//g.transform.position = new Vector3( 0, worldDimension.y/2f, 0 );
PhysicsObjectGraphics obj = g.GetComponent<PhysicsObjectGraphics>();
objects.Add( obj );
obj.World = this;
obj.PhysicsObj.setPosition( g.transform.position );
}
createIt++;
}
foreach( PhysicsObjectGraphics obj in objects ){
obj.ApplyPhysics();
}
fillHash( hashCapacity, gridDimension );
foreach( PhysicsObjectGraphics obj in objects ){
List<PhysicsObjectGraphics> neighbors = neighborhood( obj, hashCapacity, gridDimension, neighborhoodRadius );
obj.PhysicsObj.Neighbors = neighbors;
obj.DensityFactor = obtainDensity( obj.PhysicsObj, neighbors, neighborhoodRadius, 2f );
}
}
Vector3 viscosity(PhysicsObjectGraphics neighbor, float deltaSeconds, float neighborhoodRadius)
{
Vector3 diffSpeed = this.getSpeed() - neighbor.PhysicsObj.getSpeed();
Vector3 diffPosition = this.getPosition() - neighbor.PhysicsObj.getPosition();
float q = diffPosition.magnitude / neighborhoodRadius;
if (q < 1)
{
float u = Vector3.Dot(diffSpeed, diffPosition);
if (u > 0)
{
return((1 - q) * (u * 0.8f + u * u * 0.8f) * diffPosition / deltaSeconds);
}
}
return(new Vector3());
}
List<PhysicsObjectGraphics> neighborhood( PhysicsObjectGraphics objPOG, int _hashCapacity, Vector3 _gridCubeDimension, float radius ){
Vector3 gridPosition = getParticleGridPosition( objPOG.PhysicsObj.getPosition(), _gridCubeDimension );
List<PhysicsObjectGraphics> result = new List<PhysicsObjectGraphics>();
// check neighbor grid cells 2D
// TODO check if the cell is inside the radius
for( int i = -1; i <= 1; i++ ){
for( int j = -1; j <= 1; j++ ){
Vector3 neighborGridPosition = new Vector3( gridPosition.x+i, gridPosition.y+j, gridPosition.z );
int neighborHash = getParticleGridPositionHash( neighborGridPosition, _hashCapacity );
foreach( PhysicsObjectGraphics obj in hashObjects[ neighborHash ] ){
// in radius?
//Debug.Log( hashObjects[ neighborHash ].Count );
if( obj != objPOG && isNeighbor( objPOG.PhysicsObj.getPosition(), obj.PhysicsObj.getPosition(), radius ) && !result.Contains(obj) ){
result.Add( obj );
}
}
}
}
return result;
}
