public virtual bool Hit(Ray ray, float min_distance, float max_distance, ref HitData hit_data)
{
Vector3 v = ray.Origin - Translation;
float a = Vector3.Dot(ray.Direction, ray.Direction);
float b = Vector3.Dot(v, ray.Direction);
float c = Vector3.Dot(v, v) - Radius * Radius;
if (b * b - a * c > 0)
{
if (FillHitData((-b - (float)Math.Sqrt(b * b - a * c)) / a, ray, min_distance, max_distance, ref hit_data))
{
return(true);
}
if (FillHitData((-b + (float)Math.Sqrt(b * b - a * c)) / a, ray, min_distance, max_distance, ref hit_data))
{
return(true);
}
}
return(false);
}
public Vector3 Emit(IMaterial material, Ray ray, HitData hit_data)
{
return(Vector3.Zero);
}
public Vector3 Emit(IMaterial material, Ray ray, HitData hit_data)
{
DiffuseLightMaterial diffuse_light_material = material as DiffuseLightMaterial;
return(diffuse_light_material.Emit.Value(hit_data.UV.X, hit_data.UV.Y, hit_data.Point));
}
public bool Scatter(IMaterial material, Ray ray, HitData hit_data, ref Vector3 attenuation, ref Ray scattered)
{
return(false);
}
protected bool FillHitData(float root, Ray ray, float min_distance, float max_distance, ref HitData hit_data)
{
if (root < min_distance || root > max_distance)
{
return(false);
}
hit_data.Distance = root;
hit_data.Point = ray.PointAt(root);
hit_data.Normal = (hit_data.Point - Translation) / Radius;
hit_data.Material = Material;
float phi = (float)Math.Atan2(hit_data.Point.Z, hit_data.Point.X);
float theta = (float)Math.Asin(hit_data.Point.Y);
hit_data.UV.X = 1 - (phi + (float)Math.PI) / (float)(2.0f * Math.PI);
hit_data.UV.Y = (theta + (float)Math.PI / 2.0f) / (float)Math.PI;
return(true);
}