【讨论】UF_CURVE_create_trim函数怎么使？

struct UF_MODL_vector_s
Overview
  
The following structure allows definition of a vector
with a variety of options. Note that associativity to
any data is not maintained unless otherwise specified.
  
Data Members
reverse_vector
int reverse_vector
Indicates if the vector calculated should then be reversed before being used. If zero, the vector is not reversed. Any other value will reverse the vector.
  
vector_type
UF_MODL_vector_type_t vector_type
Indication of which structure is being used to define the vector.
  
defined_by
UF_MODL_vector_defined_by_union_t defined_by
The definition of the vector.
  
  

UF_MODL_vector_type_e
enum UF_MODL_vector_type_e  
  
The following enum is used in the UF_MODL_vector structure
to specify how the vector is being defined.
  
UF_MODL_VECTOR_DIRECTION   
   
UF_MODL_VECTOR_AXIS   
   
UF_MODL_VECTOR_FACE_NORMAL   
   
UF_MODL_VECTOR_TWO_POINTS   
   
UF_MODL_VECTOR_PLANE_OF_CURVES   
   
UF_MODL_VECTOR_FACE_NORMALS   
   
UF_MODL_VECTOR_DIRECTION_EXACT_GEOMETRY   
   
UF_MODL_VECTOR_AXIS_EXACT_GEOMETRY   
   
UF_MODL_VECTOR_FACE_NORMALS_EXACT_GEOMETRY