/// <summary>
/// Calculates resultant PointValues when 2D Raster (img) is projected along Frustum at Mesh (vertices).
/// Mesh represented by list of vertices.
/// NOTE 1: does not currently account for occlusion.
/// NOTE 2: projection's FOV should be full FOV angles, not half-angles.
/// </summary>
public List <PointValue <T> > Intersection <T>(Frustum projection, T[,] img, List <Vector3> vertices)
{
/// setup
int imgPCi = img.GetLength(0);
int imgPCj = img.GetLength(1);
List <PointValue <T> > result = new List <PointValue <T> >();
VerticesInView = 0;
/// create occlusion grid
Dictionary <string, int> ocPixels = RequiredGrid(projection.FOV);
int ocPCi = ocPixels["i"];
int ocPCj = ocPixels["j"];
OcclusionCell <T>[,] ocGrid = new OcclusionCell <T> [ocPCi, ocPCj];
for (int i = 0; i < ocGrid.GetLength(0); i++)
{
for (int j = 0; j < ocGrid.GetLength(1); j++)
{
ocGrid[i, j].nullCell = true;
}
}
/// try each vertex
foreach (Vector3 vertex in vertices)
{
/// calculate position vector (world space)
Vector3 Pworld = Vector(projection.Transform.position, vertex);
/// convert position vector (world space) to position vector (Frustum space)
Vector3 Plocal = projection.Transform.InverseTransformVector(Pworld);
/// convert position vector (Frustum space) to view vector (Frustum space)
ViewVector Vlocal = new ViewVector(Plocal);
/// check if view vector is within Frustum FOV
if (Math.Abs(Vlocal.Theta) < projection.FOV.Theta / 2.0 &&
Math.Abs(Vlocal.Phi) < projection.FOV.Phi / 2.0)
{
VerticesInView++;
/// map view vector to occlusion grid
int ioc = (int)(ocPCi / 2 + ocPCi * (Vlocal.Theta / projection.FOV.Theta));
int joc = (int)(ocPCj / 2 + ocPCj * (Vlocal.Phi / projection.FOV.Phi));
/// add to occlusion grid as new PointValue if not occluded
if (ocGrid[ioc, joc].nullCell || Pworld.magnitude < ocGrid[ioc, joc].distance)
{
/// map view vector to img pixel grid
int iImg = (int)(imgPCi / 2 + imgPCi * (Vlocal.Theta / projection.FOV.Theta));
int jImg = (int)(imgPCj / 2 + imgPCj * (Vlocal.Phi / projection.FOV.Phi));
/// update occlusion grid
ocGrid[ioc, joc].pv = new PointValue <T>(vertex, img[iImg, jImg]);
ocGrid[ioc, joc].distance = Pworld.magnitude;
ocGrid[ioc, joc].nullCell = false;
}
}
}
for (int i = 0; i < ocGrid.GetLength(0); i++)
{
for (int j = 0; j < ocGrid.GetLength(1); j++)
{
if (!ocGrid[i, j].nullCell)
{
result.Add(ocGrid[i, j].pv);
}
}
}
nonOccludedVertices = result.Count;
return(result);
}
/// <summary>
/// Calculates resultant PointValues when 2D Raster (img) is projected along Frustum at Mesh (vertices).
/// Mesh represented by list of vertices.
/// NOTE 1: does not currently account for occlusion.
/// NOTE 2: projection's FOV should be full FOV angles, not half-angles.
/// NOTE 3: Attempted to make generic. See note at begining of file.
/// </summary>
public List <PointValue <byte> > Intersection(Frustum projection, byte[,] img, List <Vector3> vertices)
{
/// setup
ImgPCi = img.GetLength(0);
ImgPCj = img.GetLength(1);
VerticesInView = 0;
/// update occlusion grid
/// Cannot predeclare OcPixels because cannot add Dictionary components in declaration.
Dictionary <string, int> OcPixels = RequiredGrid(projection.FOV);
// Predeclaration of ocGrid has no benefit due to array type an dynamic size.
OcclusionCell <byte>[,] ocGrid = new OcclusionCell <byte> [OcPixels["i"], OcPixels["j"]];
for (i = 0; i < OcPixels["i"]; i++)
{
for (j = 0; j < OcPixels["j"]; j++)
{
ocGrid[i, j].nullCell = true;
}
}
/// try each vertex
for (i = 0; i < vertices.Count; i++)
{
/// calculate position vector (world space)
Vector(projection.Transform.position, vertices[i], ref Pworld);
/// convert position vector (world space) to position vector (Frustum space)
Plocal = projection.Transform.InverseTransformVector(Pworld);
/// convert position vector (Frustum space) to view vector (Frustum space)
Vlocal.Update(Plocal);
/// check if view vector is within Frustum FOV
if (Math.Abs(Vlocal.Theta) < projection.FOV.Theta / 2.0 &&
Math.Abs(Vlocal.Phi) < projection.FOV.Phi / 2.0)
{
VerticesInView++;
/// map view vector to occlusion grid
iOc = (int)(OcPixels["i"] / 2 + OcPixels["i"] * (Vlocal.Theta / projection.FOV.Theta));
jOc = (int)(OcPixels["j"] / 2 + OcPixels["j"] * (Vlocal.Phi / projection.FOV.Phi));
/// add to occlusion grid as new PointValue if not occluded
if (ocGrid[iOc, jOc].nullCell || Pworld.magnitude < ocGrid[iOc, jOc].distance)
{
/// map view vector to img pixel grid
iImg = (int)(ImgPCi / 2 + ImgPCi * (Vlocal.Theta / projection.FOV.Theta));
jImg = (int)(ImgPCj / 2 + ImgPCj * (Vlocal.Phi / projection.FOV.Phi));
/// update occlusion grid
ocGrid[iOc, jOc].pv.Update(vertices[i], img[iImg, jImg]);
ocGrid[iOc, jOc].distance = Pworld.magnitude;
ocGrid[iOc, jOc].nullCell = false;
}
}
}
/// Alteratively could prevent reallocating using Result.Clear(), however is slow
Result = new List <PointValue <byte> >();
for (i = 0; i < ocGrid.GetLength(0); i++)
{
for (j = 0; j < ocGrid.GetLength(1); j++)
{
if (!ocGrid[i, j].nullCell)
{
Result.Add(ocGrid[i, j].pv);
}
}
}
NonOccludedVertices = Result.Count;
return(Result);
}