public override float GenerateRayDifferential(CameraSample sample, out RayDifferential ray)
{
// Generate raster and camera samples
Point Pras = new Point(sample.ImageX, sample.ImageY, 0);
Point Pcamera = RasterToCamera.TransformPoint(ref Pras);
ray = new RayDifferential(new Point(0, 0, 0), Vector.Normalize((Vector)Pcamera), 0.0f);
// Modify ray for depth of field
if (LensRadius > 0.0f)
{
// Sample point on lens
float lensU, lensV;
MonteCarloUtilities.ConcentricSampleDisk(sample.LensU, sample.LensV, out lensU, out lensV);
lensU *= LensRadius;
lensV *= LensRadius;
// Compute point on plane of focus
float ft = FocalDistance / ray.Direction.Z;
Point Pfocus = ray.Evaluate(ft);
// Update ray for effect of lens
ray.Origin = new Point(lensU, lensV, 0.0f);
ray.Direction = Vector.Normalize(Pfocus - ray.Origin);
}
// Compute offset rays for _PerspectiveCamera_ ray differentials
ray.RxOrigin = ray.RyOrigin = ray.Origin;
ray.RxDirection = Vector.Normalize((Vector)Pcamera + _dxCamera);
ray.RyDirection = Vector.Normalize((Vector)Pcamera + _dyCamera);
ray.Time = sample.Time;
ray = CameraToWorld.TransformRayDifferential(ray);
return(1.0f);
}
public PerspectiveCamera(
AnimatedTransform cameraToWorld, float[] screenWindow,
float shutterOpen, float shutterClose,
float lensRadius, float focalDistance,
float fieldOfView,
Film film)
: base(cameraToWorld, Transform.Perspective(fieldOfView, 1e-2f, 1000.0f), screenWindow, shutterOpen, shutterClose, lensRadius, focalDistance, film)
{
// Compute differential changes in origin for perspective camera rays
_dxCamera = RasterToCamera.TransformPoint(new Point(1, 0, 0)) - RasterToCamera.TransformPoint(new Point(0, 0, 0));
_dyCamera = RasterToCamera.TransformPoint(new Point(0, 1, 0)) - RasterToCamera.TransformPoint(new Point(0, 0, 0));
}
