protected TreeBranch(List <TreeBranch> branches, int generation, int generations, Vector3 from, Vector3 tangent, Vector3 normal, Vector3 binormal, float length, float radius, float offset, TreeData data)
{
this.generation = generation;
this.fromRadius = radius;
this.toRadius = (generation == 0) ? 0f : radius *data.radiusAttenuation;
this.from = from;
var scale = Mathf.Lerp(1f, data.growthAngleScale, 1f - 1f * generation / generations);
var rotation = Quaternion.AngleAxis(scale * data.GetRandomGrowthAngle(), normal) * Quaternion.AngleAxis(scale * data.GetRandomGrowthAngle(), binormal);
this.to = from + rotation * tangent * length;
this.length = length;
this.offset = offset;
segments = BuildSegments(data, fromRadius, toRadius, normal, binormal);
branches.Add(this);
children = new List <TreeBranch>();
if (generation > 0)
{
int count = data.GetRandomBranches();
for (int i = 0; i < count; i++)
{
float ratio;
if (count == 1)
{
// for zero division
ratio = 1f;
}
else
{
ratio = Mathf.Lerp(0.5f, 1f, (1f * i) / (count - 1));
}
var index = Mathf.FloorToInt(ratio * (segments.Count - 1));
var segment = segments[index];
Vector3 nt, nn, nb;
if (ratio >= 1f)
{
// sequence branch
nt = segment.Frame.Tangent;
nn = segment.Frame.Normal;
nb = segment.Frame.Binormal;
}
else
{
var phi = Quaternion.AngleAxis(i * 90f, tangent);
// var psi = Quaternion.AngleAxis(data.branchingAngle, normal) * Quaternion.AngleAxis(data.branchingAngle, binormal);
var psi = Quaternion.AngleAxis(data.branchingAngle, normal);
var rot = phi * psi;
nt = rot * tangent;
nn = rot * normal;
nb = rot * binormal;
}
var child = new TreeBranch(
branches,
this.generation - 1,
generations,
segment.Position,
nt,
nn,
nb,
length * Mathf.Lerp(1f, data.lengthAttenuation, ratio),
radius * Mathf.Lerp(1f, data.radiusAttenuation, ratio),
offset + length,
data
);
children.Add(child);
}
}
}
protected TreeBranch(int generation, int generations, Vector3 from, Vector3 tangent, Vector3 normal, Vector3 binormal, float length, float radius, float offset, TreeData data)
{
this.generation = generation;
this.fromRadius = radius;
// 枝先である場合は先端の太さが0になる
this.toRadius = (generation == 0) ? 0f : radius *data.radiusAttenuation;
this.from = from;
// 枝先ほど分岐する角度が大きくなる
var scale = Mathf.Lerp(1f, data.growthAngleScale, 1f - 1f * generation / generations);
// normal方向の回転
var qn = Quaternion.AngleAxis(scale * data.GetRandomGrowthAngle(), normal);
// binormal方向の回転
var qb = Quaternion.AngleAxis(scale * data.GetRandomGrowthAngle(), binormal);
// 枝先が向いているtangent方向にqn * qbの回転をかけつつ、枝先の位置を決める
this.to = from + (qn * qb) * tangent * length;
this.length = length;
this.offset = offset;
// モデル生成に必要な節を構築
segments = BuildSegments(data, fromRadius, toRadius, normal, binormal);
children = new List <TreeBranch>();
if (generation > 0)
{
// 分岐する数を取得
int count = data.GetRandomBranches();
for (int i = 0; i < count; i++)
{
float ratio; // [0.0 ~ 1.0]
if (count == 1)
{
// 分岐数が1である場合（0除算を回避）
ratio = 1f;
}
else
{
ratio = Mathf.Lerp(0.5f, 1f, (1f * i) / (count - 1));
}
// 分岐元の節を取得
var index = Mathf.FloorToInt(ratio * (segments.Count - 1));
var segment = segments[index];
// 分岐元の節が持つベクトルをTreeBranchに渡すことで滑らかな分岐を得る
Vector3 nt = segment.Frame.Tangent;
Vector3 nn = segment.Frame.Normal;
Vector3 nb = segment.Frame.Binormal;
var child = new TreeBranch(
this.generation - 1,
generations,
segment.Position,
nt,
nn,
nb,
length * Mathf.Lerp(1f, data.lengthAttenuation, ratio),
radius * Mathf.Lerp(1f, data.radiusAttenuation, ratio),
offset + length,
data
);
children.Add(child);
}
}
}
