/// <summary>
/// Node 分割
/// </summary>
/// <param name="maxLevel">限制Node最大的深度</param>
/// <param name="maxItems">限制Node包含的最大数量</param>
public void Distribute(int maxLevel, int maxItems)
{
if (Level < maxLevel && (SplitAxis != LEAF || ItemCount > maxItems))
{
if (SplitAxis == LEAF)
{
Split();
}
while (Head.Next != Tail)
{
OOItem i1 = Head.Next;
i1.Detach();
float mid = i1.Obj.Box.Mid[SplitAxis];
float size = i1.Obj.Box.Size[SplitAxis];
if (mid + size < mSplitValue)
{
i1.Attach(Left);
}
else if (mid - size > mSplitValue)
{
i1.Attach(Right);
}
else
{
OOItem i2 = i1.Split();
i1.Attach(Left);
i2.Attach(Right);
}
}
}
Merge(maxItems);
}
public void DeleteItems()
{
while (Head.Next != Tail)
{
OOItem i1 = Head.Next;
i1.Detach();
i1.Unlink();
}
}
// 在该Node 添加 一个 Object
public void AddObject(OOModel obj)
{
// Node内存储的数据为 OOItem
OOItem item = new OOItem();
// OOItem 与 OOObject 进行 相互 关联
// OOItem 记录 Obj
item.Obj = obj;
// OOObject 链表头 添加 OOItem
item.Link(obj.Head);
// 将 item 挂到该 Node
item.Attach(this);
}
public OONode()
{
Head = new OOItem();
Tail = new OOItem();
Box = new OOBox(Vector3.one * float.MaxValue, Vector3.one * float.MinValue);
SplitAxis = LEAF;
Visible = 0;
ItemCount = 0;
Left = null;
Right = null;
Parent = null;
Head.Prev = null;
Head.Next = Tail;
Tail.Next = null;
Tail.Prev = Head;
}
public OOModel(MannulDraw drawer)
{
Drawer = drawer;
MeshFilter mf = drawer.gameObject.GetComponent <MeshFilter>();
Model = new OOMesh(mf);
Box = new OOBox(Vector3.one * float.MaxValue, Vector3.one * float.MinValue);
UpdateTransform();
Head = new OOItem();
Tail = new OOItem();
Tail.CNext = null;
Head.CPrev = null;
Head.CNext = Tail;
Tail.CPrev = Head;
CanOcclude = 1;
// GeoDebugDrawUtils.DrawAABB(Box.Min, Box.Max);
}
/// <summary>
/// 截头体剔除算法入口
/// </summary>
private void FrustumCull()
{
mMinQueue.Clear();
PushBox(Tree.Root, ref Tree.Root.Box);
while (mMinQueue.Size > 0)
{
OONode nd = (OONode)mMinQueue.Dequeue();
if (mFrustum.Test(ref nd.Box) > 0)
{
nd.Distribute(mMaxLevel, mMaxItems);
OOItem itm = nd.Head.Next;
while (itm != nd.Tail)
{
OOModel obj = itm.Obj;
if (obj.TouchId != Tree.TouchCounter)
{
obj.TouchId = Tree.TouchCounter;
if (mFrustum.Test(ref obj.Box) > 0)
{
obj.Next = null;
if (mVisible == null)
{
mVisible = mTail = obj;
}
else
{
mTail.Next = obj;
mTail = obj;
}
}
}
itm = itm.Next;
}
if (nd.SplitAxis != OONode.LEAF)
{
PushBox(nd.Left, ref nd.Left.Box);
PushBox(nd.Right, ref nd.Right.Box);
}
}
}
}
/// <summary>
/// 老旧的遮挡剔除算法入口
/// </summary>
private void OcclusionCullOld()
{
Stat[0] = Stat[1] = 0;
Map.Clear();
mMinQueue.Clear();
mMaxQueue.Clear();
PushBox(Tree.Root, ref Tree.Root.Box);
while (mMinQueue.Size > 0)
{
OONode nd = (OONode)mMinQueue.Dequeue();
nd.Distribute(mMaxLevel, mMaxItems);
MinMax(ref nd.Box, ref nd.Box.Zmin, ref nd.Box.Zmax);
if (nd.SplitAxis != OONode.LEAF)
{
if (nd.Visible != 0 || IsVisible(1, ref nd.Box, nd.Box.Zmin) != 0)
{
nd.Visible = 1;
PushBox(nd.Left, ref nd.Left.Box);
PushBox(nd.Right, ref nd.Right.Box);
}
else
{
nd.Visible = 0;
if (nd.Parent != null)
{
nd.Parent.Visible = 0;
}
}
}
else
{
if (IsVisible(1, ref nd.Box, nd.Box.Zmin) != 0)
{
OOItem itm = nd.Head.Next;
while (itm != nd.Tail)
{
if (itm.Obj.TouchId != Tree.TouchCounter)
{
itm.Obj.TouchId = Tree.TouchCounter;
OOModel obj = itm.Obj;
float dis = -Vector3.Dot(obj.Box.Mid, mLook);
float d = Vector3.Dot(mAbsLook, obj.Box.Size);
obj.Box.Zmin = dis - d;
obj.Box.Zmax = dis + d;
if (IsVisible(0, ref obj.Box, 0) != 0)
{
mMaxQueue.Enqueue(obj.Box.Zmax, obj, obj.Box.Zmax);
obj.Next = null;
if (mVisible == null)
{
mVisible = mTail = obj;
}
else
{
mTail.Next = obj;
mTail = obj;
}
}
}
itm = itm.Next;
}
}
if (nd.Parent != null)
{
nd.Parent.Visible = 0;
}
}
}
}
/// <summary>
/// 遮挡剔除 算法入口
/// </summary>
private void OcclusionCull()
{
Stat[0] = Stat[1] = 0;
Map.Clear();
mMinQueue.Clear();
mMaxQueue.Clear();
PushBox2(Tree.Root, ref Tree.Root.Box);
// 按 负无穷范数(最小值) 作为优先权中 遍历
while (mMinQueue.Size > 0)
{
OONode nd = (OONode)mMinQueue.Dequeue();
nd.Distribute(mMaxLevel, mMaxItems);
MinMax(ref nd.Box, ref nd.Box.Zmin, ref nd.Box.Zmax);
if (nd.SplitAxis != OONode.LEAF) // 非叶节点
{
// 该节点存在两个子节点
// 如果 该节点 Visible 为可见 ,则不需要进一步计算
// 如果 该结点 Visible 为不可见,则进一步计算判断可见性
// KDTree的Node不是每次重新分配，带有一定的缓存功能。所以， Visible 可以加速计算
// 存在一个问题：如果所有的物体都分到了一个Node中，可能会不停的划分到最大深度。后期需要优化
if ((nd.Visible != 0) || IsVisible(1, ref nd.Box, nd.Box.Zmin) != 0)
{
// 标记为可见
nd.Visible = 1;
// 父节点可见,接下来判断左右孩子结点的可见性
PushBox2(nd.Left, ref nd.Left.Box);
PushBox2(nd.Right, ref nd.Right.Box);
}
else
{
// 标记为不可见
nd.Visible = 0;
if (nd.Parent != null)
{
nd.Parent.Visible = 0;
}
}
}
else // 叶节点
{
// 叶节点的Box测试
if (IsVisible(1, ref nd.Box, nd.Box.Zmin) != 0)
{
OOItem itm = nd.Head.Next;
// 保存需要绘制的物体，以 Zmax 为优先级排序
while (itm != nd.Tail)
{
if (itm.Obj.TouchId != Tree.TouchCounter)
{
itm.Obj.TouchId = Tree.TouchCounter;
OOModel obj = itm.Obj;
MinMax(ref obj.Box, ref obj.Box.Zmin, ref obj.Box.Zmax);
// 查询物体的Box是否可见
if (IsVisible(0, ref obj.Box, 0) != 0)
{
// 如果一个物体的Box可见，则为待绘制的物体
mMaxQueue.Enqueue(obj.Box.Zmax, obj, obj.Box.Zmax);
obj.Next = null;
if (mVisible == null)
{
mVisible = mTail = obj;
}
else
{
mTail.Next = obj;
mTail = obj;
}
}
}
itm = itm.Next;
}
}
if (nd.Parent != null)
{
nd.Parent.Visible = 0;
}
}
}
#if TEST_DRAW
VisualKDTree(Tree.Root);
if (mMaxQueue.Size > 0)
{
DebugUtils.Info("OcclusionCull", "Before Max Left: ", mMaxQueue.Size);
FlushOccluders(float.MaxValue);
DebugUtils.Info("OcclusionCull", "After Max Left: ", mMaxQueue.Size);
}
Map.DrawScreenShot();
#endif
}