uint8_t num_ucps; /* also set to max if ClipDistance is used */
uint8_t edgeflag; /* attribute index of edgeflag input */
bool need_vertex_id;
uint8_t num_ucps; /* also set to max if ClipDistance is used */
uint8_t edgeflag; /* attribute index of edgeflag input */
bool need_vertex_id;