public void BuildProbabilities(double _CameraTheta, ParametrizedSpace _Probas)
{
Vector ViewTS = new Vector(Math.Sin(_CameraTheta), 0.0, Math.Cos(_CameraTheta));
Vector LightTS = new Vector(0, 0, 0);
double L = 2.0 * _CameraTheta / Math.PI;
Vector2 Center = new Vector2(0, L); // We choose the center to be (0,ThetaD0)
// Vector2 U = new Vector2( L, -L ); // U direction goes down to (ThetaH0,0)
Vector2 U = new Vector2(0.5 / L, -0.5 / L); // U direction goes down to (ThetaH0,0)
// Vector2 V = new Vector2( 1-L, 1-L ); // V direction goes up toward (PI/2, PI/2) (singularity when _CameraTheta=PI/2 !)
// Vector2 V = new Vector2( 0.5 / (1-L), 0.5 / (1-L) ); // V direction goes up toward (PI/2, PI/2) (singularity when _CameraTheta=PI/2 !)
Vector2 V = new Vector2(1.0 / (1 - L), 1.0 / (1 - L)); // V direction goes up toward (PI/2, PI/2) (singularity when _CameraTheta=PI/2 !)
double Normalizer = 100.0 / (SAMPLES_COUNT_PHI * SAMPLES_COUNT_THETA);
Vector2 ST = new Vector2(0, 0);
Vector2 Delta = new Vector2(0, 0);
Vector2 UV = new Vector2(0, 0);
_Probas.Clear();
int ScaleAngle = Math.Min(89, (int)(90 * L));
for (var Y = 0; Y < SAMPLES_COUNT_PHI; Y++)
{
var PhiL = Math.PI * ((double)Y / SAMPLES_COUNT_PHI - 0.5);
var CosPhiL = Math.Cos(PhiL);
var SinPhiL = Math.Sin(PhiL);
for (var X = 0; X < SAMPLES_COUNT_THETA; X++)
{
// var ThetaL = 0.5 * Math.PI * X / SAMPLES_COUNT_THETA;
var ThetaL = Math.Asin(Math.Sqrt((double)X / SAMPLES_COUNT_THETA)); // Account for cosine weight of samples
var CosThetaL = Math.Cos(ThetaL);
var SinThetaL = Math.Sin(ThetaL);
LightTS.x = SinThetaL * SinPhiL;
LightTS.y = SinThetaL * CosPhiL;
LightTS.z = CosThetaL;
var Half = (ViewTS + LightTS).Normalize();
var ThetaH = Math.Acos(Half.z);
var ThetaD = Math.Acos(ViewTS.Dot(Half));
// Normalize in ST space
ST.x = 2 * ThetaH / Math.PI;
ST.y = 2 * ThetaD / Math.PI;
// Transform into UV space
Delta = ST - Center;
UV.x = Delta.Dot(U);
UV.y = Delta.Dot(V);
// Find scaling factor
int ScaleX = Math.Max(0, Math.Min(PROBA_ARRAY_SIZE - 1, (int)(PROBA_ARRAY_SIZE * UV.x)));
double Scale = m_Scales[ScaleAngle, ScaleX];
UV.y *= Scale;
_Probas.Accumulate(UV, Normalizer);
}
}
}
public void BuildProbabilities( double _CameraTheta, ParametrizedSpace _Probas )
{
Vector ViewTS = new Vector( Math.Sin( _CameraTheta ), 0.0, Math.Cos( _CameraTheta ) );
Vector LightTS = new Vector( 0, 0, 0 );
double L = 2.0 * _CameraTheta / Math.PI;
Vector2 Center = new Vector2( 0, L ); // We choose the center to be (0,ThetaD0)
// Vector2 U = new Vector2( L, -L ); // U direction goes down to (ThetaH0,0)
Vector2 U = new Vector2( 0.5 / L, -0.5 / L ); // U direction goes down to (ThetaH0,0)
// Vector2 V = new Vector2( 1-L, 1-L ); // V direction goes up toward (PI/2, PI/2) (singularity when _CameraTheta=PI/2 !)
// Vector2 V = new Vector2( 0.5 / (1-L), 0.5 / (1-L) ); // V direction goes up toward (PI/2, PI/2) (singularity when _CameraTheta=PI/2 !)
Vector2 V = new Vector2( 1.0 / (1-L), 1.0 / (1-L) ); // V direction goes up toward (PI/2, PI/2) (singularity when _CameraTheta=PI/2 !)
double Normalizer = 100.0 / (SAMPLES_COUNT_PHI * SAMPLES_COUNT_THETA);
Vector2 ST = new Vector2( 0, 0 );
Vector2 Delta = new Vector2( 0, 0 );
Vector2 UV = new Vector2( 0, 0 );
_Probas.Clear();
int ScaleAngle = Math.Min( 89, (int) (90 * L) );
for ( var Y=0; Y < SAMPLES_COUNT_PHI; Y++ )
{
var PhiL = Math.PI * ((double) Y / SAMPLES_COUNT_PHI - 0.5);
var CosPhiL = Math.Cos( PhiL );
var SinPhiL = Math.Sin( PhiL );
for ( var X=0; X < SAMPLES_COUNT_THETA; X++ )
{
// var ThetaL = 0.5 * Math.PI * X / SAMPLES_COUNT_THETA;
var ThetaL = Math.Asin( Math.Sqrt( (double) X / SAMPLES_COUNT_THETA ) ); // Account for cosine weight of samples
var CosThetaL = Math.Cos( ThetaL );
var SinThetaL = Math.Sin( ThetaL );
LightTS.x = SinThetaL * SinPhiL;
LightTS.y = SinThetaL * CosPhiL;
LightTS.z = CosThetaL;
var Half = (ViewTS + LightTS).Normalize();
var ThetaH = Math.Acos( Half.z );
var ThetaD = Math.Acos( ViewTS.Dot( Half ) );
// Normalize in ST space
ST.x = 2*ThetaH/Math.PI;
ST.y = 2*ThetaD/Math.PI;
// Transform into UV space
Delta = ST - Center;
UV.x = Delta.Dot( U );
UV.y = Delta.Dot( V );
// Find scaling factor
int ScaleX = Math.Max( 0, Math.Min( PROBA_ARRAY_SIZE-1, (int) (PROBA_ARRAY_SIZE * UV.x) ) );
double Scale = m_Scales[ScaleAngle,ScaleX];
UV.y *= Scale;
_Probas.Accumulate( UV, Normalizer );
}
}
}
