/// <summary>
/// 相机位置到物体Box的最大最小值距离( 无穷范数 )
/// </summary>
/// <param name="box">AABB数据</param>
/// <param name="min">AABB距相机距离最近值</param>
/// <param name="max">AABB距相机距离最远值</param>
private void MinMax(ref OOBox box, ref float min, ref float max)
{
min = 0;
max = float.MinValue;
// 相机到Box中心的向量三维度的距离表示
Vector3 diff = (mPosition - box.Mid).Abs();
// 三维度距离与Box此寸比较,计算最大和最小距离值
for (int i = 0; i < 3; i++)
{
float d1 = diff[i] - box.Size[i];
if (d1 > min)
{
min = d1;
}
float d2 = diff[i] + box.Size[i];
if (d2 > max)
{
max = d2;
}
}
// 不能小于0, 比如在内部
if (min < 0)
{
min = 0;
}
}
/// <summary>
/// 将物体保存到 小根堆
/// </summary>
/// <param name="obj">待添加物体</param>
/// <param name="box">添加物体的Box的大小</param>
private void PushBox2(object obj, ref OOBox box)
{
// 最近和最远平面距离计算
MinMax(ref box, ref box.Zmin, ref box.Zmax);
// 以最近距离为权重值,添加到优先队列
mMinQueue.Enqueue(box.Zmin, obj, box.Zmin);
}
/// <summary>
/// 判断 Box 的可见性
/// </summary>
/// <param name="flush">Node结点的Box 为 1, 需要将缓存的遮挡物先绘制再查询; Node中的Item为0.</param>
/// <param name="box">AABB数据</param>
/// <param name="dist">最近距离( 负无穷范数 )</param>
/// <returns></returns>
private int IsVisible(int flush, ref OOBox box, float dist)
{
// Box放大一点点
OOBox q = box;
q.Size = box.Size + Vector3.one * mSafeDistance;
// 截头体测试
int visible = mFrustum.Test(ref q);
if (visible == 0)
{
return(0);
}
// 相机在Box内部
if (visible == 2)
{
return(1);
}
if (flush != 0)
{
// 绘制Box最远距离 小于 dist的物体
FlushOccluders(dist);
}
return(QueryBox(ref box));
}
public int Test(ref OOBox b)
{
int i;
float m, n;
Vector3 diff = (b.Mid - mPosition).Abs();
// 相机位置在 b 内部, 返回2
if (diff.Less(b.Size))
{
return(2);
}
// 检测Box与6个平面的相交
for (i = 0; i < 6; i++)
{
// box 中心点 到 面的有符号距离计算
m = Vector3.Dot(b.Mid, mPlanes[i]) + mPlanes[i][3];
// b 的 size 在 面法向 最大投影距离.必定为一个正值
Vector3 plane = mPlanes[i].Abs();
n = Vector3.Dot(b.Size, plane);
// 如果 存在一个面,使得 m 值大于 最大投影值,可以肯定 box 不相较于 截头体
if (m > n)
{
return(0);
}
}
// 这种情况存在: box 与 截头体相交; box在截头体内部.
// 这两种情况,都需要保留 box 对应的 物体
return(1);
}
public OOMesh(MeshFilter filter)
{
MeshFilter = filter;
MeshFilter.sharedMesh.RecalculateBounds();
#if TEST_DRAW_ONE
Vector3 world1 = new Vector3(1.14f, -0.7f, -5.94f);
Vector3 world2 = new Vector3(1.14f, 1.96f, -7.81f);
Vector3 world3 = new Vector3(7.28f, -0.7f, -5.94f);
Vertices = new Vector3[]
{
filter.transform.worldToLocalMatrix.MultiplyPoint3x4(world1),
filter.transform.worldToLocalMatrix.MultiplyPoint3x4(world2),
filter.transform.worldToLocalMatrix.MultiplyPoint3x4(world3)
};
world1 = Camera.main.WorldToScreenPoint(world1) * 32;
world2 = Camera.main.WorldToScreenPoint(world2) * 32;
world3 = Camera.main.WorldToScreenPoint(world3) * 32;
DebugUtils.Info("OOModel", string.Format("world1({0}, {1})", world1.x, world1.y));
DebugUtils.Info("OOModel", string.Format("world2({0}, {1})", world2.x, world2.y));
DebugUtils.Info("OOModel", string.Format("world3({0}, {1})", world3.x, world3.y));
Faces = new Vector3i[] { new Vector3i(0, 1, 2) };
#else
Vertices = MeshFilter.sharedMesh.vertices;
Faces = ArrayToList(MeshFilter.sharedMesh.triangles);
#endif
NumVert = Vertices.Length;
NumFace = Faces.Length;
CameraSpaceVertices = new Vector3[NumVert];
ClipSpaceVertices = new Vector4[NumVert];
Bounds b = MeshFilter.sharedMesh.bounds;
Box = new OOBox(b.min, b.max);
}
/// <summary>
/// 按照相机朝向计算距离值
/// </summary>
/// <param name="obj">待添加物体</param>
/// <param name="box">待添加物体的Box数据</param>
private void PushBox(object obj, ref OOBox box)
{
float dis, d;
dis = -Vector3.Dot(box.Mid, mLook);
d = Vector3.Dot(mAbsLook, box.Size);
box.Zmin = dis - d;
box.Zmax = dis + d;
mMinQueue.Enqueue(box.Zmin, obj, box.Zmin);
}
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>
/// 根据相机位置,获得所在区域,然后获取Box可见面构造的轮廓
/// max
/// 6 --------- 7
/// / | / |
/// 2 --------- 3 |
/// | | | |
/// | | | |
/// | 4 --------- 5
/// | / | /
/// 0 --------- 1
/// min
/// </summary>
/// <param name="box">查询Box的可见性</param>
/// <returns></returns>
private int QueryBox(ref OOBox box)
{
Vector3 min = box.Min;
Vector3 max = box.Max;
// 8顶点索引和数据对应
Vector4[] vxt = new Vector4[8];
vxt[0] = new Vector4(min[0], min[1], min[2], 1);
vxt[1] = new Vector4(max[0], min[1], min[2], 1);
vxt[2] = new Vector4(min[0], max[1], min[2], 1);
vxt[3] = new Vector4(max[0], max[1], min[2], 1);
vxt[4] = new Vector4(min[0], min[1], max[2], 1);
vxt[5] = new Vector4(max[0], min[1], max[2], 1);
vxt[6] = new Vector4(min[0], max[1], max[2], 1);
vxt[7] = new Vector4(max[0], max[1], max[2], 1);
// 区域码计算
int cd = 0;
if (mPosition[0] < min[0])
{
// 左面之左
cd |= 1;
}
if (mPosition[0] > max[0])
{
// 右面之右
cd |= 2;
}
if (mPosition[1] < min[1])
{
// 下面之下
cd |= 4;
}
if (mPosition[1] > max[1])
{
// 上面之上
cd |= 8;
}
if (mPosition[2] < min[2])
{
// 进面之近
cd |= 16;
}
if (mPosition[2] > max[2])
{
// 远面之远
cd |= 32;
}
// 到这一步,已经过了截头体测试.物体均在相机视角内
// 索引相机能见到的顶点
int[] stt = STAB[cd];
// 数组0索引表示能见到的顶点数量,后面的数组索引记录Box的顶点索引
int vp = stt[0];
#if TEST_DRAW
List <Vector3> polygon = new List <Vector3>();
List <Vector3> clipPolygon = new List <Vector3>();
#endif
// 遍历顶点
for (int i = 0; i < vp; i++)
{
// 获得顶点索引
int j = stt[i + 1];
// 将顶点变换到裁剪空间
mClip.mClipSpaceVertices[i] = mPV * vxt[j];
#if TEST_DRAW
polygon.Add(vxt[j]);
// 裁剪前
clipPolygon.Add(mClip.mClipSpaceVertices[i] * (1 / mClip.mClipSpaceVertices[i][3]));
#endif
}
#if TEST_DRAW
// 绘制可见多边形
GeoDebugDrawUtils.DrawPolygon(polygon, Color.red);
GeoDebugDrawUtils.DrawPolygon(clipPolygon, Color.red);
DrawNDCBox();
#endif
// 对Box的轮廓进行裁剪计算,返回裁剪后的顶点数
vp = mClip.ClipAndProject(vp);
#if TEST_DRAW
clipPolygon.Clear();
// z 方向上 偏移 0.01
Vector4 offset = new Vector4(0, 0, 0.01f, 0);
for (int i = 0; i < vp; ++i)
{
clipPolygon.Add(offset + mClip.mClipSpaceVertices[i]);
}
// 裁剪后
GeoDebugDrawUtils.DrawPolygon(clipPolygon, Color.blue);
#endif
if (vp < 3)
{
return(0);
}
int res = Map.QueryPolygon(mClip.mScreenSpaceVertices, vp);
return(res);
}
