typedef int PK_facet_go_parameters_t; This field can take any one of the following values. PK_facet_go_parameters_no_c : do not output surface parameter data PK_facet_go_parameters_d0_c : output surface params at vertices PK_facet_go_parameters_d1_c : output surface params + first derivatives PK_facet_go_parameters_d2_c : output surface params + all second derivs