//-----------------------------------------------------------------------------
// Computes ambient lighting along a specified ray.
//-----------------------------------------------------------------------------
void CalcRayAmbientLighting(
const Vector &vStart,
const Vector &vEnd,
Vector color[MAX_LIGHTSTYLES],
Vector &colorSum )
{
Ray_t ray;
ray.Init( vStart, vEnd, vec3_origin, vec3_origin );
directlight_t *pSkyLight = FindAmbientSkyLight();
colorSum.Init();
CLightSurface surfEnum;
if (!surfEnum.FindIntersection( ray ))
return;
// This is the faster path; it looks slightly different though
if (surfEnum.m_pSurface->dispinfo == -1)
{
ComputeLightmapColorFromAverage( surfEnum.m_pSurface, pSkyLight, color, colorSum );
}
else
{
ComputeLightmapColorDisplacement( surfEnum.m_pSurface, pSkyLight, surfEnum.m_LuxelCoord, color, colorSum );
}
}
//-----------------------------------------------------------------------------
// Computes ambient lighting along a specified ray.
// Ray represents a cone, tanTheta is the tan of the inner cone angle
//-----------------------------------------------------------------------------
void CalcRayAmbientLighting( int iThread, const Vector &vStart, const Vector &vEnd, float tanTheta, Vector color[MAX_LIGHTSTYLES] )
{
Ray_t ray;
ray.Init( vStart, vEnd, vec3_origin, vec3_origin );
directlight_t *pSkyLight = FindAmbientSkyLight();
CLightSurface surfEnum(iThread);
if (!surfEnum.FindIntersection( ray ))
return;
// compute the approximate radius of a circle centered around the intersection point
float dist = ray.m_Delta.Length() * tanTheta * surfEnum.m_HitFrac;
// until 20" we use the point sample, then blend in the average until we're covering 40"
// This is attempting to model the ray as a cone - in the ideal case we'd simply sample all
// luxels in the intersection of the cone with the surface. Since we don't have surface
// neighbor information computed we'll just approximate that sampling with a blend between
// a point sample and the face average.
// This yields results that are similar in that aliasing is reduced at distance while
// point samples provide accuracy for intersections with near geometry
float scaleAvg = RemapValClamped( dist, 20, 40, 0.0f, 1.0f );
if ( !surfEnum.m_bHasLuxel )
{
// don't have luxel UV, so just use average sample
scaleAvg = 1.0;
}
float scaleSample = 1.0f - scaleAvg;
if (scaleAvg != 0)
{
ComputeLightmapColorFromAverage( surfEnum.m_pSurface, pSkyLight, scaleAvg, color );
}
if (scaleSample != 0)
{
ComputeLightmapColorPointSample( surfEnum.m_pSurface, pSkyLight, surfEnum.m_LuxelCoord, scaleSample, color );
}
}
