private void GenerateSegment(Vector3 startPosition, Quaternion orientation, float segmentGrowth, List <int> startRing)
{
int segmentNumber = Mathf.FloorToInt(Growth - segmentGrowth);
float startScale = Mathf.Pow(segmentGrowth, Species.ScaleExponent);
float endScale = Mathf.Pow(segmentGrowth - 1, Species.ScaleExponent);
float segmentLength = Species.SegmentLength * startScale;
if (Species.SegmentAngleNoise > 0)
{
Quaternion noiseRotation = Quaternion.LookRotation(Random.insideUnitSphere, Vector3.up);
orientation = Quaternion.Lerp(orientation, noiseRotation, Species.SegmentAngleNoise);
}
// build stem segment geometry
int startVC = mg.VertexCount;
mg.SetMaterial(0);
float sliceAngle = 2 * Mathf.PI / Species.StemSides;
if (startRing == null)
{
startRing = tempIndices.GetNext();
startRing.Clear();
for (int i = 0; i < Species.StemSides; i++)
{
startRing.Add(mg.AddVertex(RadialPoint(i * sliceAngle, Species.SegmentRadius * startScale, 0)));
}
}
if (segmentGrowth >= 1)
{
// normal (tube) segment
List <int> endRing = tempIndices.GetNext();
endRing.Clear();
for (int i = 0; i < Species.StemSides; i++)
{
endRing.Add(mg.AddVertex(RadialPoint(i * sliceAngle, Species.SegmentRadius * endScale, segmentLength)));
}
for (int i = 0; i < Species.StemSides; i++)
{
int j = (i + 1) % Species.StemSides;
mg.AddFace(endRing[i], endRing[j], startRing[j], startRing[i]);
}
startRing = endRing;
}
else
{
// end (cone) segment
int endPoint = mg.AddVertex(new Vector3(0, segmentLength, 0));
for (int i = 0; i < Species.StemSides; i++)
{
int j = (i + 1) % Species.StemSides;
mg.AddFace(endPoint, startRing[j], startRing[i]);
}
}
// orient and position stem segment
int endVC = mg.VertexCount;
mg.RotateVertices(startVC, endVC, orientation);
mg.TranslateVertices(startVC, endVC, startPosition);
// grow leaves
if (segmentNumber > 0 && segmentGrowth > Species.LeafThreshold && Species.LeavesPerSegment > 0)
{
float leafBaseRotation = segmentNumber * 180 * (Fibonacci[Species.WhorlNumber] / (float)Fibonacci[Species.WhorlNumber + 1]);
float leafAngleSeparation = 360f / Species.LeavesPerSegment;
for (int i = 0; i < Species.LeavesPerSegment; i++)
{
Quaternion rotate = Quaternion.AngleAxis(leafBaseRotation + i * leafAngleSeparation, Vector3.up);
if (Species.LeafAngleNoise > 0)
{
Quaternion noiseRotation = Quaternion.LookRotation(Random.insideUnitSphere, Vector3.up);
rotate = Quaternion.Lerp(rotate, noiseRotation, Species.LeafAngleNoise);
}
GenerateLeaf(startPosition, rotate * orientation, segmentGrowth - Species.LeafThreshold);
}
}
// grow a new segment if necessary
if (segmentGrowth > 1)
{
Vector3 endOffset = Vector3.up * segmentLength;
Vector3 endPosition = startPosition + orientation * endOffset;
GenerateSegment(endPosition, orientation, segmentGrowth - 1, startRing);
}
}