/// <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));
}
private Vector3 SampleLocalPosition(SamplerBase sampler)
{
double rand = sampler.GetRandom();
double areaRand = rand * (m_Area0 * 2.0 + m_Area1 * 2.0 + m_Area2 * 2.0);
Vector2 sample = sampler.SampleUnitSquare();
if (areaRand < m_Area0)
{
return(new Vector3(-scale.x * 0.5 + scale.x * sample.x, -scale.y * 0.5 + scale.y * sample.y, -scale.z * 0.5));
}
else if (areaRand >= m_Area0 && areaRand < m_Area0 * 2.0)
{
return(new Vector3(-scale.x * 0.5 + scale.x * sample.x, -scale.y * 0.5 + scale.y * sample.y, scale.z * 0.5));
}
else if (areaRand >= m_Area0 * 2.0 && areaRand < m_Area0 * 2.0 + m_Area1)
{
return(new Vector3(-scale.x * 0.5, -scale.y * 0.5 + scale.y * sample.x, -scale.z * 0.5 + scale.z * sample.y));
}
else if (areaRand >= m_Area0 * 2.0 + m_Area1 && areaRand < m_Area0 * 2.0 + m_Area1 * 2.0)
{
return(new Vector3(scale.x * 0.5, -scale.y * 0.5 + scale.y * sample.x, -scale.z * 0.5 + scale.z * sample.y));
}
else if (areaRand >= m_Area0 * 2.0 + m_Area1 * 2.0 && areaRand < m_Area0 * 2.0 + m_Area1 * 2.0 + m_Area2)
{
return(new Vector3(-scale.x * 0.5 + scale.x * sample.x, -scale.y * 0.5, -scale.z * 0.5 + scale.z * sample.y));
}
else
{
return(new Vector3(-scale.x * 0.5 + scale.x * sample.x, scale.y * 0.5, -scale.z * 0.5 + scale.z * sample.y));
}
}
public override Ray GetRay(int x, int y, SamplerBase sampler)
{
if (useThinLens)
{
return(GetThinLensRayFromPixel(x, y, sampler));
}
var sample = sampler.SampleUnitSquare();
return(GetRayFromPixel(sample.x + x, sample.y + y));
}
