public static bool IsVisible(this PerspectiveCamera camera, Point3D worldPoint)
{
try
{
Point3D local = ProjectionCameraExtension.GetWorldToLocal(camera).Transform(worldPoint);
// camera lookdirection is along -Z axis
if (local.Z >= 0.0)
{
return(false);
}
const double deg2rad = 0.01745329;
double distance = Abs(local.Z);
double frustrumHeight = 2.0 * distance * Tan(camera.FieldOfView * deg2rad * 0.5);
if (Abs(local.X) > frustrumHeight / 2.0)
{
return(false);
}
if (Abs(local.Y) > frustrumHeight / 2.0)
{
return(false);
}
return(true);
}
catch { return(false); }
}
public static bool IsVisible(this PerspectiveCamera camera, Point3D worldPoint, double aspectRatio)
{
try
{
Point3D local = ProjectionCameraExtension.GetWorldToLocal(camera).Transform(worldPoint);
// camera lookdirection is along -Z axis
if (local.Z >= 0.0)
{
return(false);
}
const double deg2rad = 0.01745329;
double distance = Abs(local.Z);
double horizontalFOV = camera.FieldOfView;
double verticalFOV = camera.FieldOfView;
if (aspectRatio >= 1)
{
verticalFOV = horizontalFOV / aspectRatio;
}
else
{
horizontalFOV = verticalFOV * aspectRatio;
}
double frustrumWidth = 2.0 * distance * Tan(horizontalFOV * deg2rad * 0.5);
double frustrumHeight = 2.0 * distance * Tan(verticalFOV * deg2rad * 0.5);
if (Abs(local.X) > frustrumWidth / 2.0)
{
return(false);
}
if (Abs(local.Y) > frustrumHeight / 2.0)
{
return(false);
}
return(true);
}
catch { return(false); }
}
