private static Vector3D[] GetVelocities(HullVoronoiExploder_Shard[] hullShards, HullVoronoiExploder_ShotHit[] hits, double hullRadius, HullVoronoiExploder_Options options)
{
//TODO: When the asteroid shards aren't resmoothed, the velocities are very small
//
//Maybe add more orth velocity
//
//Maybe pull the hit source slightly into the asteroid --- done
//
//Maybe add some random velocity (size proportional to the velocity) --- done
Vector3D[] retVal = CalculateVelocites(hullShards.Select(o => o.Center_ParentCoords).ToArray(), hits, hullRadius, options);
if (options.RandomVelocityPercent != null)
{
retVal = retVal.
Select(o => o + Math3D.GetRandomVector_Spherical(o.Length * options.RandomVelocityPercent.Value)).
ToArray();
}
return retVal;
}
private static Vector3D[] CalculateVelocites(Point3D[] centers, HullVoronoiExploder_ShotHit[] hits, double hullRadius, HullVoronoiExploder_Options options)
{
Vector3D[] retVal = new Vector3D[centers.Length];
foreach (var hit in hits)
{
Point3D shotStart = hit.Hit.Item1;
if (options.InteriorVelocityCenterPercent != null)
{
shotStart += ((hit.Hit.Item2 - hit.Hit.Item1) * options.InteriorVelocityCenterPercent.Value);
}
//Vector3D[] velocities = DistributeForces(centers, shotStart, hit.Shot.Item2 * (hit.Shot.Item3 * options.ShotMultiplier), hullRadius, options);
Vector3D[] velocities = DistributeForces(centers, shotStart, hit.Shot.Item2 * hit.Shot.Item3, hullRadius, options);
for (int cntr = 0; cntr < retVal.Length; cntr++)
{
retVal[cntr] += velocities[cntr];
}
}
return retVal;
}
private static Point3D[] GetVoronoiCtrlPoints(HullVoronoiExploder_ShotHit[] hits, ITriangle[] convexHull, int minCount, int maxCount, double aabbLen)
{
const int MIN = 5;
Random rand = StaticRandom.GetRandomForThread();
#region examine hits
Tuple<int, double>[] hitsByLength = hits.
Select((o, i) => Tuple.Create(i, (o.Hit.Item2 - o.Hit.Item1).Length)).
OrderByDescending(o => o.Item2).
ToArray();
double totalLength = hitsByLength.Sum(o => o.Item2);
Tuple<int, double>[] hitsByPercentLength = hitsByLength.
Select(o => Tuple.Create(o.Item1, o.Item2 / totalLength)).
ToArray();
#endregion
#region define control point cones
double entryRadius = aabbLen * .05;
double exitRadius = aabbLen * .35;
double maxAxisLength = aabbLen * .75;
int count = hits.Length * 2;
count += (totalLength / (aabbLen * .1)).ToInt_Round();
if (count < minCount) count = minCount;
else if (count > maxCount) count = maxCount;
#endregion
#region randomly pick control points
// Keep adding rings around shots until the count is exceeded
var sets = new List<Tuple<int, List<Point3D>>>();
int runningSum = 0;
// Make sure each hit line gets some points
for (int cntr = 0; cntr < hits.Length; cntr++)
{
AddToHitline(ref runningSum, sets, cntr, hits[cntr].Hit, entryRadius, exitRadius, maxAxisLength, rand);
}
// Now that all hit lines have points, randomly choose lines until count is exceeded
while (runningSum < count)
{
var pointsPerLength = hitsByLength.
Select(o =>
{
var pointsForIndex = sets.FirstOrDefault(p => p.Item1 == o.Item1);
int countForIndex = pointsForIndex == null ? 0 : pointsForIndex.Item2.Count;
return Tuple.Create(o.Item1, countForIndex / o.Item2);
}).
OrderBy(o => o.Item2).
ToArray();
double sumRatio = pointsPerLength.Sum(o => o.Item2);
var pointsPerLengthNormalized = pointsPerLength.
Select(o => Tuple.Create(o.Item1, o.Item2 / sumRatio)).
ToArray();
int index = UtilityCore.GetIndexIntoList(rand.NextPow(3), pointsPerLengthNormalized);
AddToHitline(ref runningSum, sets, index, hits[index].Hit, entryRadius, exitRadius, maxAxisLength, rand);
}
#endregion
#region remove excessive points
while (runningSum > count)
{
Tuple<int, double>[] fractions = sets.
Select((o, i) => Tuple.Create(i, o.Item2.Count.ToDouble() / runningSum.ToDouble())).
OrderByDescending(o => o.Item2).
ToArray();
int fractionIndex = UtilityCore.GetIndexIntoList(rand.NextPow(1.5), fractions); //nextPow will favor the front of the list, which is where the rings with the most points are
int setIndex = fractions[fractionIndex].Item1;
sets[setIndex].Item2.RemoveAt(UtilityCore.GetIndexIntoList(rand.NextDouble(), sets[setIndex].Item2.Count));
runningSum--;
}
#endregion
#region ensure enough for voronoi algorithm
List<Point3D> retVal = new List<Point3D>();
retVal.AddRange(sets.SelectMany(o => o.Item2));
// The voronoi algrorithm fails if there aren't at least 5 points (really should fix that). So add points that are
// way away from the hull. This will make the voronoi algorithm happy, and won't affect the local results
if (count < MIN)
{
retVal.AddRange(
Enumerable.Range(0, MIN - count).
Select(o => Math3D.GetRandomVector_Spherical_Shell(aabbLen * 20).ToPoint())
);
}
#endregion
return retVal.ToArray();
}