public static Solid FromString(string content)
{
var lines = content.Trim().Split('\n');
int c = 0;
Triangle t = new Triangle();
List<Triangle> triangles = new List<Triangle>();
for (int i = 0; i < lines.Count(); i++)
{
if (c == 0)
{
t = new Triangle();
t.MaterialIndex = (int)Convert.ToDecimal(lines[i]);
t.Points = new Vector3[3];
}
else
{
var split = lines[i].Split(' ');
t.Points[c - 1] = new Vector3()
{
//X = (float)Convert.ToDecimal(split[0]), // this way won't detected 'E'
//Y = (float)Convert.ToDecimal(split[1]),
//Z = (float)Convert.ToDecimal(split[2])
X = float.Parse(split[0]),
Y = float.Parse(split[1]),
Z = float.Parse(split[2])
};
}
c++;
if (c > 3)
{
c = 0;
Vector3 u = t.Points[1] - t.Points[0];
Vector3 v = t.Points[2] - t.Points[0];
t.Normal = u * v;
t.Normal = Vector3.Normalize(t.Normal);
triangles.Add(t);
}
}
return new Solid()
{
triangles = triangles
};
}
private static double Intersection(Ray r, Triangle tr)
{
double[,] a = new double[3, 3] {
{tr.Points[0].X - tr.Points[1].X, tr.Points[0].X - tr.Points[2].X, r.direction.X},
{tr.Points[0].Y - tr.Points[1].Y, tr.Points[0].Y - tr.Points[2].Y, r.direction.Y},
{tr.Points[0].Z - tr.Points[1].Z, tr.Points[0].Z - tr.Points[2].Z, r.direction.Z}};
double detA = Determinant(a);
double[,] b = new double[3, 3] {
{tr.Points[0].X - r.origin.X, tr.Points[0].X - tr.Points[2].X, r.direction.X},
{tr.Points[0].Y - r.origin.Y, tr.Points[0].Y - tr.Points[2].Y, r.direction.Y},
{tr.Points[0].Z - r.origin.Z, tr.Points[0].Z - tr.Points[2].Z, r.direction.Z}};
double detB = Determinant(b) / detA;
if (detB < 0) return -1;
double[,] y = new double[3, 3] {
{tr.Points[0].X - tr.Points[1].X, tr.Points[0].X - r.origin.X, r.direction.X},
{tr.Points[0].Y - tr.Points[1].Y, tr.Points[0].Y - r.origin.Y, r.direction.Y},
{tr.Points[0].Z - tr.Points[1].Z, tr.Points[0].Z - r.origin.Z, r.direction.Z}};
double detY = Determinant(y) / detA;
if (detY < 0) return -1;
if (detB + detY >= 1) return -1;
double[,] t = new double[3, 3] {
{tr.Points[0].X - tr.Points[1].X, tr.Points[0].X - tr.Points[2].X, tr.Points[0].X - r.origin.X},
{tr.Points[0].Y - tr.Points[1].Y, tr.Points[0].Y - tr.Points[2].Y, tr.Points[0].Y - r.origin.Y},
{tr.Points[0].Z - tr.Points[1].Z, tr.Points[0].Z - tr.Points[2].Z, tr.Points[0].Z - r.origin.Z}};
double detT = Determinant(t) / detA;
if (detT < EPSILON) return -1;
return detT;
}