void Update()
{
UpdateLights();
if (!_render)
{
return;
}
if (_photons == null)
{
_photons = new Photon[maxPhotons];
}
// add new photons
if (_lights.Length > 0)
{
for (int i = 0; i < _photons.Length; i++)
{
if (!_photons[i].alive)
{
float u = Random.value * _totalLightSurfaceArea;
LightSource light = null;
float cdf = 0f;
for (int li = 0; li < _lights.Length; li++)
{
cdf += /*_lights[li].intensity **/ _lights[li]._surfaceArea;
if (u <= cdf)
{
light = _lights[li];
break;
}
}
if (light == null)
{
light = _lights[_lights.Length - 1];
}
light.MakePhoton(ref _photons[i]);
_photons[i].alive = true;
}
}
}
// trace photons
for (int i = 0; i < _photons.Length; i++)
{
//// the should all be alive - no branch needed
//if( !_photons[i].alive )
// continue;
RaycastHit hitInfo;
if (Physics.Raycast(_photons[i].position + 0.01f * _photons[i].next_dir, _photons[i].next_dir, out hitInfo))
{
_photons[i].intensity /= 1f + (hitInfo.point - _photons[i].position).magnitude * 0.1f;
//_photons[i].intensity /= Mathf.Max( 1f, (hitInfo.point - _photons[i].position).sqrMagnitude );
//if( Random.value < 0.2f )
// Debug.DrawLine( _photons[i].position, hitInfo.point, new Color( 1f, 1f, 1f, _photons[i].intensity.magnitude*0.1f ), 1f );
Color existingRadiance = Color.black;
LightFlood lf = hitInfo.collider.GetComponent <LightFlood>();
if (lf)
{
lf.Hit(ref _photons[i], ref hitInfo, out existingRadiance);
}
// cosine rule for energy loss
_photons[i].intensity *= Vector3.Dot(hitInfo.normal, -_photons[i].next_dir);
//_photons[i].intensity += 0.1f * new Vector3( existingRadiance.r, existingRadiance.g, existingRadiance.b );
_photons[i].intensity = new Vector3(_photons[i].intensity.x * lf.color.r, _photons[i].intensity.y * lf.color.g, _photons[i].intensity.z * lf.color.b);
// add whatever radiance was there before as well
_photons[i].position = hitInfo.point;
if (Vector3.Dot(_photons[i].next_dir = Random.onUnitSphere, hitInfo.normal) < 0f)
{
_photons[i].next_dir = -_photons[i].next_dir;
}
if (_photons[i].intensity.sqrMagnitude < 0.01f)
{
_photons[i].alive = false;
}
}
else
{
//Debug.DrawLine( _photons[i].position, _photons[i].position + 100f * _photons[i].next_dir, new Color( 1f, 1f, 1f, _photons[i].intensity * 0.01f ), 1f );
// photon escaped scene
_photons[i].alive = false;
}
}
}