public Option <RayHitpoint> TryHit(PositionableSphere positionableSphere, Ray ray, RayParameter bottomBoundary,
RayParameter topBoundary)
{
var(positionable, sphere) = positionableSphere;
var originToCenter = ray.Origin - positionable.Translation;
var a = Vector3.Dot(ray.Direction, ray.Direction);
var b = 2.0f * Vector3.Dot(originToCenter, ray.Direction);
var c = Vector3.Dot(originToCenter, originToCenter) -
sphere.Radius * sphere.Radius;
var discriminant = b * b - 4 * a * c;
if (discriminant < 0)
{
return(Option <RayHitpoint> .Empty);
}
var temp = new RayParameter((-b - (float)Math.Sqrt(discriminant)) / (2.0f * a));
if (temp < topBoundary.Value && temp > bottomBoundary.Value)
{
var hitPoint = ray.PointAt(temp);
var normal = GetNormalAtPoint(hitPoint, positionableSphere);
return(new Option <RayHitpoint>(new RayHitpoint(hitPoint, normal, temp)));
}
temp = new RayParameter((-b + (float)Math.Sqrt(discriminant)) / (2.0f * a));
if (temp < topBoundary.Value && temp > bottomBoundary.Value)
{
var hitPoint = ray.PointAt(temp);
var normal = GetNormalAtPoint(hitPoint, positionableSphere);
return(new Option <RayHitpoint>(new RayHitpoint(hitPoint, normal, temp)));
}
return(Option <RayHitpoint> .Empty);
}
public bool Hit(Bounds bounds,
Ray ray,
RayParameter bottomBoundary,
RayParameter topBoundary)
{
var tMin = bottomBoundary.Value;
var tMax = topBoundary.Value;
for (var i = 0; i < 3; ++i)
{
var invRayDir = 1 / ray.Direction.Enumerate(i);
var t0 = (bounds.Minimum.Enumerate(i) - ray.Origin.Enumerate(i)) * invRayDir;
var t1 = (bounds.Maximum.Enumerate(i) - ray.Origin.Enumerate(i)) * invRayDir;
if (invRayDir < 0.0f)
{
Maths.Swap(ref t0, ref t1);
}
tMin = t0 > tMin ? t0 : tMin;
tMax = t1 < tMax ? t1 : tMax;
if (t0 > t1)
{
return(false);
}
}
return(true);
}
public Option <EntityRayHitpoint> TryHit(Ray ray, RayParameter bottomBoundary, RayParameter topBoundary)
{
if (!_hitableBoundsComputer.Hit(_bounds, ray, bottomBoundary, topBoundary))
{
return(Option <EntityRayHitpoint> .Empty);
}
var leftHit = Left.TryHit(ray, bottomBoundary, topBoundary);
var rightHit = Right.TryHit(ray, bottomBoundary, topBoundary);
return(leftHit.HasValue switch
{
true when rightHit.HasValue => leftHit.Value.Hitpoint.T < rightHit.Value.Hitpoint.T
? leftHit
: rightHit,
true => leftHit,
_ => rightHit.HasValue ? rightHit : Option <EntityRayHitpoint> .Empty
});
private Color ThrowRay(Ray ray, RayParameter minParameter, RayParameter maxParameter, Color color, int depth)
{
var hitPoint = Scene.TryHit(ray, minParameter, maxParameter);
if (hitPoint.HasValue)
{
// Scatter
var rayScattered = Scene.Scatterables[hitPoint.Value.Id]
.Scatter(ray, hitPoint.Value.Hitpoint, new Color(color.Value));
if (++depth > 50)
{
return(new Color(new Vector3(0.0f)));
}
return(ThrowRay(rayScattered.Scattered, minParameter, hitPoint.Value.Hitpoint.T, rayScattered.Color,
depth));
}
return(color);
}
public Option <EntityRayHitpoint> TryHit(Ray ray, RayParameter bottomBoundary, RayParameter topBoundary)
{
var hasHit = false;
var candidateParameter = topBoundary;
var candidateHitpoint = new EntityRayHitpoint();
foreach (var(id, hitable) in _hitables)
{
var contact = hitable.TryHit(ray, bottomBoundary, topBoundary);
if (contact.HasValue && contact.Value.T < candidateParameter)
{
candidateParameter = contact.Value.T;
candidateHitpoint = new EntityRayHitpoint(id, contact);
hasHit = true;
}
}
return(hasHit
? new Option <EntityRayHitpoint>(candidateHitpoint)
: Option <EntityRayHitpoint> .Empty);
}
public bool Hit(Ray ray, RayParameter bottomBoundary, RayParameter topBoundary)
{
return(_computer.Hit(_bounds, ray, bottomBoundary, topBoundary));
}
public Option <EntityRayHitpoint> TryHit(Ray ray, RayParameter bottomBoundary, RayParameter topBoundary)
{
return(_hitableStructure.TryHit(ray, bottomBoundary, topBoundary));
}
public Option <RayHitpoint> TryHit(Ray ray, RayParameter bottomBoundary, RayParameter topBoundary)
{
return(_computer.TryHit(_sphere, ray, bottomBoundary, topBoundary));
}