typedef     struct SprObject3D {
     Uint16 no; / * Object number * /
     Uint16 dispFlag / * Display flag * /
     Uint16 vertCount; / * Number of vertices * /
     Uint16 surfaceCount; / * Number of surfaces * /
     MthXyz * vertPoint; / * Vertex coordinate table * /
     MthXyz * vertNormal; / * Vertex normal vector table * /
     SprSurface * surface; / * Surface definition table * /
     MthXyz * surfaceNormal; / * Surface normal vector table * /
     MthXyz * surfaceVert; / * Surface representative point coordinate table * /
     Uint16 ** shdIdxTbl; / * Shading index table * /
     Fixed32 surfNormK; / * Surface normal vector calculation correction value * /
     SprObject3D * next; / * Next 3D object * /
} SprObject3D;

no is for user callback routines to identify the object table and is optional.

 dispFlag b15, b14 = 00: Polygon display
                 = 10: Polyline display 

             b12 = 1: Double-sided polygon 

           b9, b8 = 00: No shading
                   01: Flat shading
                   10: Gouraud shading 

              b4 = 1: Inter-object connection polygon object 

 vertNormal: Set when performing Gouraud shading.
surface: Pointer of the table that defines the vertices constituting the surface and color information for each surface
surfaceNormal: table pointer that defines normals for each surface
surfaceVert: Sets the pointer of the representative point (center point) coordinate table of the surface to be referenced when calculating the brightness of the surface.
              Set. If 0 is set, the first vertex of the surface definition is used as the representative point.
shdIdxTbl: When performing flat shading with a shading table, shading
              Set the table index table. When Gouraud shading is specified,
              ∙ When this parameter is specified, shdIdxTbl [0] is set to Gouraud shading gray code.
              This is a table. Flat shading and surface definition drawing mode is texture
              If this parameter is specified when specified, shdIdxTbl [0] is set to flat shaded.
              グ Gray code table.
surfNormK: Calculates the surface normal vector for this object using the SPR_3SetNormVect () routine.
              When calculating, or when this object is an inter-object connected polygon object
              Specify in. For details, see sur on the MTH_ComputeNormVect () routine of the mathematical calculation library.
              Refer to the fNormK parameter.
              ∙ Specify a negative value for inter-object connection polygon objects.