GetPatchNormals Method

Gets a collection of coordinates representing the vertices of the normals for the specified patch (part).

Syntax

C#
Visual Basic (Declaration)

public void GetPatchNormals( 
   int patchIndex,
   ref ICollection<Coordinate3D> normals
)

Public Sub GetPatchNormals( _
   ByVal patchIndex As Integer, _
   ByRef normals As ICollection(Of Coordinate3D) _
)

Parameters

patchIndex: The index of the patch. Must be greater than or equal to zero and less than PartCount.
normals: The collection into which the coordinates are copied. If normals is null, then a list is allocated.

Exceptions

Exception	Description
System.ArgumentException	The patch index must be >= 0.
System.ArgumentException	The patch index must be less than the number of patches (parts) in the multipatch.
System.InvalidOperationException	This multipatch does not have normals.

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>
public void DoSomethingWithNormalCoordinates(Multipatch multipatch)
{
  if (multipatch.HasNormals)
  {
    // Allocate the list only once
    int numPoints = multipatch.PointCount;
    ICollection<Coordinate3D> normals = new List<Coordinate3D>(numPoints);

    // The parts of a multipatch are also called patches
    int numPatches = multipatch.PartCount;

    for (int patchIndex = 0; patchIndex < numPatches; patchIndex++)
    {
      multipatch.GetPatchNormals(patchIndex, ref normals);

      // Do something with the normals for this patch.
    }
  }
}

Requirements

Target Platforms: Windows 10, Windows 8.1

Reference

Multipatch Class
Multipatch Members