// Inner function to rotate a vector around another vector by angle
Rvector3 Camera::RotateAround(Rvector3 vector, Real angle, Rvector3 axis){
// Store the old x,y,z values
Real oldX = vector[0], oldY = vector[1], oldZ = vector[2];
// Store the cos and sin values, for convenience
Real c = cos(angle), s = sin(angle);
// Store the x,y,z values of the axis, for convenience
axis.Normalize();
Real x = axis[0], y = axis[1], z = axis[2];
// Rotate the vector around the axis
vector.Set((1+(1-c)*(x*x-1))*oldX + (-z*s+(1-c)*x*y)*oldY + (y*s+(1-c)*x*z)*oldZ,
(z*s+(1-c)*x*y)*oldX + (1+(1-c)*(y*y-1))*oldY + (-x*s+(1-c)*y*z)*oldZ,
(-y*s+(1-c)*x*z)*oldX + (x*s+(1-c)*y*z)*oldY + (1+(1-c)*(z*z-1))*oldZ);
// Make sure the direction vectors are still orthogonal to each other
//ReorthogonalizeVectors();
return vector;
}
//--------------------------------------------------------------------
void SurfaceMesh::BuildNormals ()
// Create the normal vectors for the faces
{
for (Integer i=0; i<=FacesSize-1; ++i)
{
ZFace& face (Faces[i]);
Rvector3 x = Vectors[face.VertexIndex[0]].WrtBody.ConvertToRvector3();
Rvector3 y = Vectors[face.VertexIndex[1]].WrtBody.ConvertToRvector3();
Rvector3 z = Vectors[face.VertexIndex[2]].WrtBody.ConvertToRvector3();
Rvector3 xy = y-x;
Rvector3 yz = z-y;
Rvector3 n = Cross(xy,yz);
if (n.GetMagnitude() != 0)
n = n.Normalize();
int index = MakeVector (n,false);
for (Integer j=0; j<=3-1; ++j)
face.NormalIndex[j] = index;
}
}
//-------------------------------------------------------------------------------
bool PolyhedronBody::FaceNormals()
{
PolygonFace face;
Rvector3 n;
Rvector3 r1, r2, A, B, C;
fn.clear();
// Create normal vector list based on facesList:
Real x, y, z;
for (UnsignedInt i = 0; i < facesList.size(); ++i)
{
// Get indices of triangle ith:
face = facesList[i];
A.Set(verticesList[face[0]].Get(0), verticesList[face[0]].Get(1), verticesList[face[0]].Get(2)); // vertex A of triangle ABC
B.Set(verticesList[face[1]].Get(0), verticesList[face[1]].Get(1), verticesList[face[1]].Get(2)); // vertex B of triangle ABC
C.Set(verticesList[face[2]].Get(0), verticesList[face[2]].Get(1), verticesList[face[2]].Get(2)); // vertex C of triangle ABC
r1 = B - A; // vector AB
r2 = C - B; // vector BC
x = r1[1]*r2[2] - r1[2]*r2[1];
y = r1[2]*r2[0] - r1[0]*r2[2];
z = r1[0]*r2[1] - r1[1]*r2[0];
n.Set(x,y,z); // n = AB x BC
if (n.Norm() < 1.0e-15)
return false;
n.Normalize(); // normal vector of triangle ABC
fn.push_back(n); // add normal vector to the normal vectors list
}
#ifdef DEBUG_FACENORMALS_CALCULATION
MessageInterface::ShowMessage("List of normal vectors:\n");
for (UnsignedInt i = 0; i < fn.size(); ++i)
{
MessageInterface::ShowMessage("%.15lf %.15lf %.15lf\n", fn[i][0], fn[i][1], fn[i][2]);
}
#endif
return true;
}