float BerconGradient::getGradientValueNormal(ShadeContext& sc) {
switch (p_normalType) {
case 0: { // View
return -DotProd(sc.Normal(), sc.V());
}
case 1: { // Local X
return (sc.VectorTo(sc.Normal(), REF_OBJECT)).x;
}
case 2: { // Local Y
return (sc.VectorTo(sc.Normal(), REF_OBJECT)).y;
}
case 3: { // Local Z
return (sc.VectorTo(sc.Normal(), REF_OBJECT)).z;
}
case 4: { // World X
return (sc.VectorTo(sc.Normal(), REF_WORLD)).x;
}
case 5: { // World Y
return (sc.VectorTo(sc.Normal(), REF_WORLD)).y;
}
case 6: { // World Z
return (sc.VectorTo(sc.Normal(), REF_WORLD)).z;
}
case 7: { // Camera X
return sc.Normal().x; //(sc.VectorTo(sc.Normal(), REF_CAMERA)).x;
}
case 8: { // Camera Y
return sc.Normal().y; //(sc.VectorTo(sc.Normal(), REF_CAMERA)).y;
}
case 9: { // Camera Z
return sc.Normal().z; //(sc.VectorTo(sc.Normal(), REF_CAMERA)).z;
}
case 10: { // To Object
if (sc.InMtlEditor() || !p_node)
return -DotProd(sc.Normal(), sc.V());
return DotProd(sc.Normal(), FNormalize(sc.PointFrom((p_node->GetNodeTM(sc.CurTime())).GetTrans(),REF_WORLD) - sc.P()));
}
case 11: { // Object Z
if (sc.InMtlEditor() || !p_node)
return -DotProd(sc.Normal(), sc.V());
return DotProd(sc.Normal(), FNormalize(sc.VectorFrom(p_node->GetNodeTM(sc.CurTime()).GetRow(2),REF_WORLD)));
}
}
return 0.f;
}
// perpendicular to N, in the U (reference) direction
Point3 GetTangent( ShadeContext &sc, int uvChan )
{
// Point3 basisVecs[ 3 ];
// sc.DPdUVW( basisVecs, uvChan ); // 0 is vtxclr, 1..n is uv channels, max_meshmaps in mesh.h
// Point3 U = Normalize( basisVecs[0] );
Point3 U = sc.VectorFrom( Point3( 0.01f, 0.0f, 1.0f ), REF_OBJECT );
//Retry:
U = Normalize( U );
Point3 N = sc.Normal(); //assumed normalized
// the line between the tip of vec[0] and its projection on N is tangent
float UN = Dot( U, N );
// if ( Abs(UN) > 0.9999999f ){
// U = sc.VectorFrom( Point3( 0.01f, 1.0f, 0.0f ), REF_OBJECT );
// goto Retry;
// }
Point3 T = U - N * UN;
T = Normalize( T );
return T;
}