message: Can't use static variables in device functions
diff: @@ -33,7 +33,7 @@ public:
  U tr(vector<3, U> const& wo, vector<3, U> const& wi) const
  {
  // TODO: calculate w/ high precision and add to math/constants.h
  - static const U one_over_four_pi = U(1.0) / (U(4.0) * constants::pi<U>());
  + const U one_over_four_pi = U(1.0) / (U(4.0) * constants::pi<U>());
  U cost = dot(wo, wi);
  