/// <summary>
/// 根据焦距和透镜半径计算光线
/// </summary>
/// <param name="x"></param>
/// <param name="y"></param>
/// <param name="sampler"></param>
/// <returns></returns>
private Ray GetThinLensRayFromPixel(int x, int y, SamplerBase sampler)
{
if (renderTarget == null)
{
throw new System.NullReferenceException();
}
var sample = sampler.SampleUnitSquare();
double px = (renderTarget.width - 1 - (sample.x + x)) / renderTarget.width * 2 - 1;
double py = (sample.y + y) / renderTarget.height * 2 - 1;
px *= m_Width;
py *= m_Height;
double per = focal / near;
px = px * per;
py = py * per;
Vector3 p = position + right * px + up * py + forward * focal;
Vector2 disk = sampler.SampleUnitDisk();
Vector3 ori = position + right * disk.x * radius + up * disk.y * radius;
Vector3 dir = (p - ori).normalized;
return(new Ray(ori, dir));
}
public override Vector3 Sample(SamplerBase sampler)
{
Vector2 pos = sampler.SampleUnitDisk();
return(position + right * (pos.x) + up * (pos.y));
}
