Mesh Topology Error C#

Rhino Developer
1

I have created a MeshBox Using its 8 Vertices. That I have in specific order.
But When I try to access the VertexTopology again in another component. it shows a different order of Points than the one I set it with.

Here is the Code

  {

    Plane mPlane = new Plane(basePlane, Plane.WorldXY.XAxis, Plane.WorldXY.YAxis);
    
    ICModule myModule = new ICModule(mPlane, width, depth, height);
    Mesh iModule = myModule.CreateBaseModule();

    A = iModule;
   // B = mPlane2;

  }

  // <Custom additional code> 

  public class ICModule
  {
    public Plane BasePlane = Plane.WorldXY;
    public double Width = 1.0;
    public double Depth = 1.0;
    public double Height = 1.0;

    //Create default constructor method/function
    public ICModule(double width, double depth, double height)
    {
      Width = width;
      Depth = depth;
      Height = height;
    }

    //Create method/function overload to be used in different situation
    //We can create more functions to make modules using the assigned variables with different inputs
    public ICModule(Plane basePlane, double width, double depth, double height)
    {
      BasePlane = basePlane;
      Width = width;
      Depth = depth;
      Height = height;
    }   

    public Mesh CreateBaseModule()
    {
      //Generate the Mesh Vertices
      List<Point3d> meshVertices = new List<Point3d>();
      {
        meshVertices.Add(BasePlane.Origin);                                                                                         
        meshVertices.Add(BasePlane.Origin + BasePlane.XAxis * Width);                                                               
        meshVertices.Add(BasePlane.Origin + BasePlane.XAxis * Width + BasePlane.YAxis * Depth);                                     
        meshVertices.Add(BasePlane.Origin + BasePlane.YAxis * Depth);                                                               
        meshVertices.Add(BasePlane.Origin + BasePlane.ZAxis * Height);                                                              
        meshVertices.Add(BasePlane.Origin + BasePlane.XAxis * Width + BasePlane.ZAxis * Height);                                    
        meshVertices.Add(BasePlane.Origin + BasePlane.XAxis * Width + BasePlane.YAxis * Depth + BasePlane.ZAxis * Height);          
        meshVertices.Add(BasePlane.Origin + BasePlane.YAxis * Depth + BasePlane.ZAxis * Height);                                    
      }
      Mesh outModule = Mesh.CreateFromBox(meshVertices, 1, 1, 1);


      return outModule;
    }
  }

  // </Custom additional code> 
}

Here in the image you can see the vertex topology on right(Expectation) on left( actual)

image
image1008×870 54.1 KB

Any Idea how to fix it.

Attached is the Script.MeshTopologyExercise.gh (5.9 KB)
MeshTopologyExercise.3dm (36.7 KB)

2

Hi @su.lwpac,

If you want to control the order of mesh vertices, then you’ll want to create the mesh yourself. Mesh.CreateFromBoxis somewhat of a black box, so it won’t provide you the control you want.

Here is an alternative method:

public Mesh CreateBaseModule()
{
  var plane = BasePlane;
  var rect0 = new Rectangle3d(plane, Width, Depth);

  plane.Origin = plane.Origin + (plane.ZAxis * Height);
  var rect1 = new Rectangle3d(plane, Width, Depth);

  var mesh = new Mesh();

  mesh.Vertices.Add(rect0.Corner(0));
  mesh.Vertices.Add(rect0.Corner(1));
  mesh.Vertices.Add(rect0.Corner(2));
  mesh.Vertices.Add(rect0.Corner(3));
  mesh.Vertices.Add(rect1.Corner(0));
  mesh.Vertices.Add(rect1.Corner(1));
  mesh.Vertices.Add(rect1.Corner(2));
  mesh.Vertices.Add(rect1.Corner(3));

  mesh.Faces.AddFace(0, 1, 5, 4);
  mesh.Faces.AddFace(1, 2, 6, 5);
  mesh.Faces.AddFace(2, 3, 7, 6);
  mesh.Faces.AddFace(3, 0, 4, 7);
  mesh.Faces.AddFace(0, 3, 2, 1);
  mesh.Faces.AddFace(4, 5, 6, 7);

  mesh.Normals.ComputeNormals();

  return mesh;
}

– Dale

1 Like
3

Hi Dale,
Yes I was looking for the way to control the order.
That works awesome.
Thanks!