surface_normals_object_model_3dT_surface_normals_object_model_3dSurfaceNormalsObjectModel3dSurfaceNormalsObjectModel3d (Operator)

Name

surface_normals_object_model_3dT_surface_normals_object_model_3dSurfaceNormalsObjectModel3dSurfaceNormalsObjectModel3d — Calculate the 3D surface normals of a 3D object model.

Signature

Description

The operator surface_normals_object_model_3dsurface_normals_object_model_3dSurfaceNormalsObjectModel3dSurfaceNormalsObjectModel3dSurfaceNormalsObjectModel3d calculates the 3D surface normals for the object ObjectModel3DObjectModel3DObjectModel3DObjectModel3DobjectModel3D using the method specified by MethodMethodMethodMethodmethod. The calculated normals are appended to the input object and the resulting object is returned in ObjectModel3DNormalsObjectModel3DNormalsObjectModel3DNormalsObjectModel3DNormalsobjectModel3DNormals.

For MethodMethodMethodMethodmethod 'mls'"mls""mls""mls""mls", the normals estimation method Moving Least Squares (MLS) is applied. The MLS method for normals estimation is essentially identical with the MLS method used by smooth_object_model_3dsmooth_object_model_3dSmoothObjectModel3dSmoothObjectModel3dSmoothObjectModel3d with the exception that in surface_normals_object_model_3dsurface_normals_object_model_3dSurfaceNormalsObjectModel3dSurfaceNormalsObjectModel3dSurfaceNormalsObjectModel3d the 3D points are not smoothed, i.e., the original 3D points of ObjectModel3DObjectModel3DObjectModel3DObjectModel3DobjectModel3D remain unchanged. For more details on the MLS as well as a full list and descriptions of the supported MLS parameters refer to smooth_object_model_3dsmooth_object_model_3dSmoothObjectModel3dSmoothObjectModel3dSmoothObjectModel3d.

If the object ObjectModel3DObjectModel3DObjectModel3DObjectModel3DobjectModel3D contains triangles, the MethodMethodMethodMethodmethod 'triangles'"triangles""triangles""triangles""triangles" can be used to obtain point normals from the normals of the triangles neighboring a point. The normals of the neighboring triangles are weighted according to the angle which the triangle encloses at the point.

If the object ObjectModel3DObjectModel3DObjectModel3DObjectModel3DobjectModel3D contains a 2D mapping (for example a 3D object model that was created with xyz_to_object_model_3dxyz_to_object_model_3dXyzToObjectModel3dXyzToObjectModel3dXyzToObjectModel3d), the MethodMethodMethodMethodmethod 'xyz_mapping'"xyz_mapping""xyz_mapping""xyz_mapping""xyz_mapping" can be used to obtain point normals from the neighborhood of the points in the 2D mapping. In a 5x5 neighborhood of the points in the 2D mapping, a plane is fit through the corresponding 3D points. The normal of this plane then gets switched in a direction consistent with the 2D mapping, for example along the viewing direction of the sensor or in the opposite direction.

Note that for points where the normal vector cannot be estimated, it is set to the zero vector. This happens, for example, if the 3D object model contains an identical point more than 'mls_kNN'"mls_kNN""mls_kNN""mls_kNN""mls_kNN" times.

Execution Information

• Multithreading type: reentrant (runs in parallel with non-exclusive operators).
• Multithreading scope: global (may be called from any thread).
• Automatically parallelized on internal data level.

This operator supports cancelling timeouts and interrupts.

Parameters

Alternatives

smooth_object_model_3dsmooth_object_model_3dSmoothObjectModel3dSmoothObjectModel3dSmoothObjectModel3d

Module

3D Metrology