public float Trace(Ray ray)
{
List <ShapeNode> allShapeNodes = new List <ShapeNode>();
_scene.Root.GetChildren(allShapeNodes, true);
float bestDist = -1;
foreach (var v in allShapeNodes)
{
float dist = v.Trace(ray);
if (dist >= 0)
{
if (bestDist < 0)
{
bestDist = dist;
}
else
{
bestDist = SMath.Min(bestDist, dist);
}
}
}
return(bestDist);
}
public override float Trace(Ray ray)
{
//{ { t1 = - o.d - Sqrt[r ^ 2 + (o.d) ^ 2 - o.o]},{ t2 = - o.d + Sqrt[r ^ 2 + (o.d) ^ 2 - o.o]} }
// o = ray's origin
// d = ray's direction
// r = sphere radius
float o_dot_d = ray._origin.DotProduct(ray._direction);
float o_dot_o = ray._origin.DotProduct(ray._origin);
float r2 = _radius * _radius;
if (o_dot_d <= 0)
{
float delta = r2 + o_dot_d * o_dot_d - o_dot_o;
if (delta >= 0)
{
float sqrtDelta = SMath.Sqrt(delta);
float t1 = -o_dot_d - sqrtDelta;
if (t1 < 0)
{
float t2 = -o_dot_d + sqrtDelta;
if (t2 >= 0)
{
return(t2);
}
}
return(t1);
}
}
return(-1.0f);
}
public bool Normalize(float tolerance = SMath.SmallNumber)
{
float squareSum = DotProduct(this);
if (squareSum > tolerance)
{
float scale = SMath.InvSqrt(squareSum);
x *= scale; y *= scale; z *= scale;
return(true);
}
return(false);
}
public Ray GenerateRay(float x, float y)
{
float fovHalfRadianY = SMath.ToRadian(_camera.FOV * 0.5f);
float fovHalfRadianX = fovHalfRadianY * _camera.Aspect;
float sx = SMath.Tan(fovHalfRadianX) * _camera.Near * x;
float sy = SMath.Tan(fovHalfRadianY) * _camera.Near * y;
Vector3 o = _cameraTransform.Translation;
Vector3 right = _cameraTransform.RightVector;
Vector3 forward = _cameraTransform.ForwardVector;
Vector3 up = _cameraTransform.UpVector;
float d = _camera.Near;
Vector3 dir = right * sx + up * sy + forward * d;
dir.Normalize();
return(new Ray(o, dir));
}