| tag_t （tag_t类型） | feature_tag | Input（输入） | Feature tag |
| UF_MODL_linked_ext_p_t | ext_data | Output to be freed 输出并释放 | Feature data. The caller defines the UF_MODL_linked_ext_t structure, and pass in a pointer to it. This routine will fill in the structure based on the feature tag. The caller is responsible for freeing any data returned in arrays. |
| int * (整数型指针) | num_groups | Output（输出） | Number of groups this feature owns |
| tag_t * * | groups | Output to be freed 输出并释放 | Groups this feature owns (may be null) |
| int * (整数型指针) | num_subfeats | Output（输出） | Number of subfeatures this feature owns |
| tag_t * * | subfeats | Output to be freed 输出并释放 | Subfeatures this feature owns (may be null) |
| double (实数型) | mass_props [ 47 ] | Output（输出） | Mass properties (same as UF_MODL_ask_mass_props_3d) [0] = Surface Area [1] = Volume [2] = Mass [3-5] = Center Of Mass (COFM), WCS [6-8] = First Moments (centroidal) [9-11] = Moments Of Inertia, WCS [12-14] = Moments Of Inertia (centroidal) [15] = Spherical Moment Of Inertia [16-18] = Inertia Products, WCS [19-21] = Inertia Products (centroidal) [22-30] = Principal Axes, WCS [31-33] = Principal Moments (centroidal) [34-36] = Radii Of Gyration, WCS [37-39] = Radii Of Gyration (centroidal) [40] = Spherical Radius Of Gyration [41-45] = Unused [46] = Density |
| UF_MODL_linked_ext_p_t | ext_data | Input（输入） | Feature data |
| tag_t * (tag_t型的指针) | feature_tag | Output（输出） | Feature tag |
| tag_t （tag_t类型） | feature_tag | Input（输入） | Feature tag |
| UF_MODL_linked_ext_p_t | ext_data | Input（输入） | Feature data |
| int (整数型) | num_bodies | Input（输入） | Number of tags in the bodies array. |
| tag_t * (tag_t型的指针) | bodies | Input（输入） | Array of body tags to identify faces from. |
| tag_t * (tag_t型的指针) | xforms | Input（输入） | Array of xforms. One for each body, determines the position of the body relative to its source geometry. NULL_TAG implies no transformation. |
| int (整数型) | num_dirs | Input（输入） | Number of directions |
| double (实数型) | direction [ ] [ 3 ] | Input（输入） | Direction to apply hidden line solution from |
| double (实数型) | chordal_tol | Input（输入） | Chordal tolerance for edges |
| int (整数型) | resolution | Input（输入） | Determines how many hatch lines drawn per face. May be one of: UF_LINKED_HL_RES_COARSE UF_LINKED_HL_RES_NORMAL UF_LINKED_HL_RES_FINE UF_LINKED_HL_RES_VERY_FINE |
| int * (整数型指针) | num_faces | Input / Output | Number of tags in the faces array. If input is > 0 will reallocate and add external faces to existing output arrays |
| tag_t * * | faces | Output to be freed 输出并释放 | Array of face tags. |
| int * * | body_index | Output to be freed 输出并释放 | Array of indices giving the body/xform the face came from. |
| int (整数型) | num_bodies | Input（输入） | Number of tags in the bodies array. |
| tag_t * (tag_t型的指针) | bodies | Input（输入） | Array of body tags to identify faces from. |
| tag_t * (tag_t型的指针) | xforms | Input（输入） | Array of xforms. One for each body, determines the position of the body relative to its source geometry. NULL_TAG implies no transformation. |
| double (实数型) | origin [ 3 ] | Input（输入） | Point to fire rays from from when ray_type = UF_LINKED_RAY_FROM_POINT |
| double (实数型) | chordal_tol | Input（输入） | Chordal tolerance for edges |
| int (整数型) | ray_type | Input（输入） | Determines orign of rays fired at each face. May be one of: UF_LINKED_RAY_ALONG_NORMS UF_LINKED_RAY_ABOVE_NORMS UF_LINKED_RAY_FROM_POINT |
| int * (整数型指针) | num_faces | Input / Output | Number of tags in the faces array. If input is > 0 will reallocate and add external faces to existing output arrays |
| tag_t * * | faces | Output to be freed 输出并释放 | Array of exterior faces. |
| int * * | body_index | Output to be freed 输出并释放 | Array of indices giving the body/xform the face came from. |