ArcGIS Pro 2.7 API Reference Guide
HasNormals Property (Multipatch)
Example 

ArcGIS.Core.Geometry Namespace > Multipatch Class : HasNormals Property
Gets a value indicating if this multipatch has normals.
Syntax
public bool HasNormals {get;}
Public ReadOnly Property HasNormals As Boolean
Remarks
The normals of a 3D object are used for lighting. They define the direction that each face will reflect light. They are usually perpendicular to the geometry but can also be defined in other directions.
Example
// <summary>
// This method gets the normal coordinate of a multipatch and does something with it.
// This method must be called on the MCT. Use QueuedTask.Run.
// </summary>
// <param name="multipatch">The input multipatch.</param>
// <param name="patchIndex">The index of the patch (part) for which to get the normal.</param>
public void DoSomethingWithNormalCoordinate(Multipatch multipatch, int patchIndex)
{
  if (multipatch.HasNormals)
  {
    // If the multipatch has normals, then the number of normals is equal to the number of points.
    int numNormals = multipatch.GetPatchPointCount(patchIndex);

    for (int pointIndex = 0; pointIndex < numNormals; pointIndex++)
    {
      Coordinate3D normal = multipatch.GetPatchNormal(patchIndex, pointIndex);

      // Do something with the normal coordinate.
    }
  }
}
Requirements

Target Platforms: Windows 10, Windows 8.1

See Also

Reference

Multipatch Class
Multipatch Members