message: Fix total internal reflection
diff: #define VSNRAY_BRDF_H 1
  #include "math/constants.h"
  -#include "math/limits.h"
  #include "math/vector.h"
  #include "fresnel.h"
  #include "sampling.h"
  @@ -304,17 +303,11 @@ public:
  U(1.0) - reflectance[0]
  );
  - auto result = select(
  + return select(
  u < reflectance[0],
  reflectance * spectrum<U>(cr * kr),
  (spectrum<U>(1.0) - reflectance) * spectrum<U>(ct * kt)
  ) / abs(dot(N, wi));
  -
  - return select(
  - length(refracted) < numeric_limits<U>::epsilon(),
  - spectrum<U>(0.0),
  - result
  - );
  }
  };
  