//计算模型点集
protected override sealed bool calcModelPts()
{
mPtData = new Point3D[4];
mPtData[1] = new Point3D(-1.0, 0.0, -0.5);
mPtData[3] = new Point3D(0.0, 0.0, 0.5);
Random r = new Random(SubDivision.Chaos_GetRandomSeed());
mPtData[0] = new Point3D(r.NextDouble(), r.NextDouble(), -0.5);
r = new Random(SubDivision.Chaos_GetRandomSeed());
mPtData[2] = new Point3D(r.NextDouble(), -1 * r.NextDouble(), -0.5);
return(true);
}
//执行生成过程，并写成3DS文件
public bool generate()
{
if (!calcModelPts())
{
return(false);
}
bool bFlag = false;
if (modelType == ModelType.ModelCrater)
{
bFlag = triangulation();
}
else
{
if (!makeFace())
{
return(false);
}
bFlag = SubDivision.subDivision(ref mDbVertices, ref uFacesIndex, uSubDivisionCount);
}
if (!bFlag)
{
return(false);
}
//拉伸
if (!strechPts())
{
return(false);
}
if (!calcTextureCoor())
{
return(false);
}
return(writeToFile());
}
public static bool calcTextureCoor(double[,] dbVertices, out double[,] dbTextureCoors, MappingType type)
{
dbTextureCoors = null;
if (dbVertices == null)
{
return(false);
}
//平铺映射
int nVertices = dbVertices.GetLength(0);
dbTextureCoors = new double[nVertices, 2];
if (type == MappingType.Flat)
{
double dbMaxX = -999, dbMaxY = -999, dbMinX = 999, dbMinY = 999;
for (int i = 0; i < nVertices; i++)
{
if (dbVertices[i, 0] > dbMaxX)
{
dbMaxX = dbVertices[i, 0];
}
if (dbVertices[i, 0] < dbMinX)
{
dbMinX = dbVertices[i, 0];
}
if (dbVertices[i, 1] > dbMaxY)
{
dbMaxY = dbVertices[i, 1];
}
if (dbVertices[i, 1] < dbMinY)
{
dbMinY = dbVertices[i, 1];
}
}
for (int i = 0; i < nVertices; i++)
{
dbTextureCoors[i, 0] = (dbVertices[i, 0] - dbMinX) / (dbMaxX - dbMinX);
dbTextureCoors[i, 1] = (dbVertices[i, 1] - dbMinY) / (dbMaxY - dbMinY);
}
}
else if (type == MappingType.Sphere)
{
for (int i = 0; i < nVertices; i++)
{
double dbX = dbVertices[i, 0];
double dbY = dbVertices[i, 1];
double dbZ = dbVertices[i, 2];
double dbR = Math.Sqrt(dbX * dbX + dbY * dbY + dbZ * dbZ);
if (dbR == 0)
{
dbTextureCoors[i, 0] = 0;
dbTextureCoors[i, 1] = 0;
continue;
}
//如果 (x, y) 在第 1 象限，则 0 < θ < π/2。
//如果 (x, y) 在第 2 象限，则 π/2 < θ≤π。
//如果 (x, y) 在第 3 象限，则 -π < θ < -π/2。
//如果 (x, y) 在第 4 象限，则 -π/2 < θ < 0。
double dbPhy = Math.Atan2(dbY, dbX);
if (dbY < 0)
{
dbPhy += Math.PI * 2;
}
// 0 ≤ θ ≤ π
double dbTheta = Math.Acos(dbZ / dbR);
Random r = new Random(SubDivision.Chaos_GetRandomSeed());
dbTextureCoors[i, 0] = dbPhy / (2 * Math.PI);
dbTextureCoors[i, 1] = dbTheta / Math.PI;
}
}
else
{
return(false);
}
return(true);
}