Parent module: Topology Module

group a3d_brepdata

Entity type is kA3DTypeTopoBrepData.


Here are some important points about A3DTopoBrepData entity orientation:

  • Edges are implicitly oriented from the Start vertex toward the End vertex.

  • 3D curves referenced by edges are oriented from the Start vertex toward the End vertex.

  • Co-edge has two flags that describe orientation:

    • Orientation with loop, which relates to the corresponding edge.

    • Orientation UV with loop, which relates to the space parametric curve attached to the co-edge, if defined.

  • Loop is oriented regarding Ampere rule (in surface parametric space).

  • Surface is oriented with the shell so that normals point from the material to the void.

Generally, a face containing a hole is defined with two loops having the same orientation. The outside loop is defined by the m_uiOuterLoopIndex member of an A3DTopoFaceData structure, regardless of orientation. To get the real face normal vector, you must consider the surface normal vector and the m_pucOrientationWithShell member of the A3DTopoShellData structure.

sa A3DTopoBrepData, A3DTopoBrepDataData, A3DTopoBrepDataGet, A3DTopoBrepDataCreate

Data Structures


BrepData structure.



Populates the A3DTopoBrepDataData structure.


Creates an A3DTopoBrepData from an A3DTopoBrepDataData structure.


Return all A3DTopoFace from an A3DTopoBrepData .


Return all A3DTopoEdge from an A3DTopoBrepData .


Return the owning A3DTopoShell of the A3DTopoFace and the orientation between them inside the given A3DTopoBrepData .


Return the owning A3DTopoShell of the A3DTopoFace inside the given A3DTopoBrepData .


Return the owning A3DTopoFace of the A3DTopoLoop inside the given A3DTopoBrepData .