public void CalculateNormals()
{
Vector3[] normals = new Vector3[vertices.Count];
for (int i = 0; i < normals.Length; i++)
{
normals[i] = new Vector3(0, 0, 0);
}
List <int> f = GetRenderingVertexIndices();
for (int i = 0; i < displayFaceSize; i += 3)
{
Vertex v1 = vertices[f[i]];
Vertex v2 = vertices[f[i + 1]];
Vertex v3 = vertices[f[i + 2]];
Vector3 nrm = VectorUtils.CalculateNormal(v1.pos, v2.pos, v3.pos);
normals[f[i + 0]] += nrm * (nrm.Length / 2);
normals[f[i + 1]] += nrm * (nrm.Length / 2);
normals[f[i + 2]] += nrm * (nrm.Length / 2);
}
for (int i = 0; i < normals.Length; i++)
{
vertices[i].nrm = normals[i].Normalized();
}
}
public void PositiveNormal()
{
// Vertices facing the camera should be in counter-clockwise order.
Vector3 v1 = new Vector3(-5, 5, 1);
Vector3 v2 = new Vector3(-5, 0, 1);
Vector3 v3 = new Vector3(0, 0, 1);
Vector3 normal = VectorUtils.CalculateNormal(v1, v2, v3).Normalized();
Assert.AreEqual(0, normal.X);
Assert.AreEqual(0, normal.Y);
Assert.AreEqual(1, normal.Z);
}
public void NegativeNormal()
{
// Vertices facing the camera in clockwise order.
Vector3 v1 = new Vector3(-5, 5, 1);
Vector3 v2 = new Vector3(-5, 0, 1);
Vector3 v3 = new Vector3(0, 0, 1);
Vector3 normal = VectorUtils.CalculateNormal(v3, v2, v1).Normalized();
Assert.AreEqual(0, normal.X);
Assert.AreEqual(0, normal.Y);
Assert.AreEqual(-1, normal.Z);
}
public void SmoothNormals()
{
Vector3[] normals = new Vector3[vertices.Count];
List <int> f = GetRenderingVertexIndices();
for (int i = 0; i < displayFaceSize; i += 3)
{
Vertex v1 = vertices[f[i]];
Vertex v2 = vertices[f[i + 1]];
Vertex v3 = vertices[f[i + 2]];
Vector3 nrm = VectorUtils.CalculateNormal(v1.pos, v2.pos, v3.pos);
normals[f[i + 0]] += nrm;
normals[f[i + 1]] += nrm;
normals[f[i + 2]] += nrm;
}
for (int i = 0; i < normals.Length; i++)
{
vertices[i].nrm = normals[i].Normalized();
}
// Compare each vertex with all the remaining vertices. This might skip some.
for (int i = 0; i < vertices.Count; i++)
{
Vertex v = vertices[i];
for (int j = i + 1; j < vertices.Count; j++)
{
Vertex v2 = vertices[j];
if (v == v2)
{
continue;
}
float dis = (float)Math.Sqrt(Math.Pow(v.pos.X - v2.pos.X, 2) + Math.Pow(v.pos.Y - v2.pos.Y, 2) + Math.Pow(v.pos.Z - v2.pos.Z, 2));
if (dis <= 0f) // Extra smooth
{
Vector3 nn = ((v2.nrm + v.nrm) / 2).Normalized();
v.nrm = nn;
v2.nrm = nn;
}
}
}
}