public override V3 GetNormal(V3 intersection = null)
{
V3 normal = Normal;
if (!HasBump())
{
normal.Normalize();
return(normal);
}
V3 AB = PointB - PointA;
V3 AC = PointC - PointA;
V3 AI = intersection - PointA;
float u = ((AC ^ Normal) * AI) / (AB ^ AC).Norm();
float v = ((Normal ^ AB) * AI) / (AC ^ AB).Norm();
BumpTexture.Bump(u, v, out float dhdu, out float dhdv);
V3 T2 = AB ^ (dhdv * normal);
V3 T3 = (dhdu * normal) ^ AC;
V3 normalBump = normal + (BumpIntensity * (T2 + T3));
normalBump.Normalize();
return(normalBump);
}
/// <summary>
/// Calcul la normale a partir d une intersection
/// A partir de cette intersection on va calculer u et v
/// </summary>
/// <param name="intersection">L intersection</param>
/// <returns>La normal par rapport a l intersection</returns>
public override V3 GetNormal(V3 intersection = null)
{
Tools.InvertCoordSpherique(FindSpherePoint(intersection), Radius, out float u, out float v);
V3 normal = GetNormal(u, v);
if (!HasBump())
{
normal.Normalize();
return(normal);
}
float uTexture = u / Tools.TAU;
float vTexture = -(v + Tools.PI2) / (Tools.PI2 + Tools.PI2);
BumpTexture.Bump(uTexture, vTexture, out float dhdu, out float dhdv);
V3 T2 = FindPointDerU(u, v) ^ (dhdv * normal);
V3 T3 = (dhdu * normal) ^ FindPointDerV(u, v);
V3 normalBump = normal + (BumpIntensity * (T2 + T3));
normalBump.Normalize();
return(normalBump);
}