private void addPosition(string[] lineParts)
{
Vec3 position = new Vec3
{
x = float.Parse(lineParts[1]),
y = float.Parse(lineParts[2]),
z = float.Parse(lineParts[3]),
};
positions.Add(position);
}
private void addNormal(string[] lineParts)
{
Vec3 normal = new Vec3
{
x = float.Parse(lineParts[1]),
y = float.Parse(lineParts[2]),
z = float.Parse(lineParts[3]),
};
normals.Add(normal);
}
private void createTangents()
{
List<Vec3> tan1 = ZeroOut(vertices.Count);
List<Vec3> tan2 = ZeroOut(vertices.Count);
int numTriangles = indices.Count;
//int triangleIndex = 0;
for (int i = 0; i < numTriangles; i+= 3)
{
int i1 = indices[i];
int i2 = indices[i + 1];
int i3 = indices[i + 2];
Vec3 v1 = vertices[i1].position;
Vec3 v2 = vertices[i2].position;
Vec3 v3 = vertices[i3].position;
Vec2 w1 = vertices[i1].textureCoord;
Vec2 w2 = vertices[i2].textureCoord;
Vec2 w3 = vertices[i3].textureCoord;
float x1 = v2.x - v1.x;
float x2 = v3.x - v1.x;
float y1 = v2.y - v1.y;
float y2 = v3.y - v1.y;
float z1 = v2.z - v1.z;
float z2 = v3.z - v1.z;
float s1 = w2.x - w1.x;
float s2 = w3.x - w1.x;
float t1 = w2.y - w1.y;
float t2 = w3.y - w1.y;
float r = 1.0f / (s1 * t2 - s2 * t1);
Vec3 sdir = new Vec3();
sdir.x = (t2 * x1 - t1 * x2) * r;
sdir.y = (t2 * y1 - t1 * y2) * r;
sdir.z = (t2 * z1 - t1 * z2) * r;
Vec3 tdir = new Vec3();
tdir.x = (s1 * x2 - s2 * x1) * r;
tdir.y = (s1 * y2 - s2 * y1) * r;
tdir.z = (s1 * z2 - s2 * z1) * r;
tan1[i1] += sdir;
tan1[i2] += sdir;
tan1[i3] += sdir;
tan2[i1] += tdir;
tan2[i2] += tdir;
tan2[i3] += tdir;
}
for (int i = 0; i < vertices.Count; i++)
{
Vec3 n = vertices[i].normal;
Vec3 t = tan1[i];
vertices[i].tangent = (Vec4)((t - n) * Vec3.Dot(n, t)).normalize();
vertices[i].tangent.w = (Vec3.Dot(Vec3.Cross(n, t), tan2[i]) < 0.0f) ? -1.0f : 1.0f;
}
}
public Vec3 normalize()
{
Vec3 normalized = new Vec3();
float length = (float)Math.Abs(Math.Sqrt(((x*x) + (y * y) + (z * z))));
normalized.x = x / length;
normalized.y = y / length;
normalized.z = z / length;
return normalized;
}
public static float Dot(Vec3 v1, Vec3 v2)
{
return v1.x*v2.x + v1.y*v2.y + v1.z*v2.z;
}
public static Vec3 Cross(Vec3 v1, Vec3 v2)
{
Vec3 vc = new Vec3();
vc.x = v1.y * v2.z - v1.z * v2.y;
vc.y = v1.z * v2.x - v1.x * v2.z;
vc.z = v1.x * v2.y - v1.y * v2.x;
return vc;
}
private List<Vec3> ZeroOut(int count)
{
List<Vec3> list = new List<Vec3>(count);
for (int i = 0; i < count; i++)
{
Vec3 v = new Vec3();
list.Add(v);
}
return list;
}