public byte TransparencyPercent {get; set;}

var coords_face1 = new List<Coordinate3D>()
{
  new Coordinate3D(12.495461061000071,41.902603910000039,62.552700000000186),
  new Coordinate3D(12.495461061000071,41.902603910000039,59.504700000004959),
  new Coordinate3D(12.495461061000071,41.902576344000067,59.504700000004959),
  new Coordinate3D(12.495461061000071,41.902603910000039,62.552700000000186),
  new Coordinate3D(12.495461061000071,41.902576344000067,59.504700000004959),
  new Coordinate3D(12.495461061000071,41.902576344000067,62.552700000000186),
};

var coords_face2 = new List<Coordinate3D>()
{
  new Coordinate3D(12.495461061000071, 41.902576344000067, 62.552700000000186),
  new Coordinate3D(12.495461061000071, 41.902576344000067, 59.504700000004959),
  new Coordinate3D(12.495488442000067, 41.902576344000067, 59.504700000004959),
  new Coordinate3D(12.495461061000071, 41.902576344000067, 62.552700000000186),
  new Coordinate3D(12.495488442000067, 41.902576344000067, 59.504700000004959),
  new Coordinate3D(12.495488442000067, 41.902576344000067, 62.552700000000186),
};

var coords_face3 = new List<Coordinate3D>()
{
  new Coordinate3D(12.495488442000067, 41.902576344000067, 62.552700000000186),
  new Coordinate3D(12.495488442000067, 41.902576344000067, 59.504700000004959),
  new Coordinate3D(12.495488442000067, 41.902603910000039, 59.504700000004959),
  new Coordinate3D(12.495488442000067, 41.902576344000067, 62.552700000000186),
  new Coordinate3D(12.495488442000067, 41.902603910000039, 59.504700000004959),
  new Coordinate3D(12.495488442000067, 41.902603910000039, 62.552700000000186),
};

var coords_face4 = new List<Coordinate3D>()
{
  new Coordinate3D(12.495488442000067, 41.902576344000067, 59.504700000004959),
  new Coordinate3D(12.495461061000071, 41.902576344000067, 59.504700000004959),
  new Coordinate3D(12.495461061000071, 41.902603910000039, 59.504700000004959),
  new Coordinate3D(12.495488442000067, 41.902576344000067, 59.504700000004959),
  new Coordinate3D(12.495461061000071, 41.902603910000039, 59.504700000004959),
  new Coordinate3D(12.495488442000067, 41.902603910000039, 59.504700000004959),
};

var coords_face5 = new List<Coordinate3D>()
{
  new Coordinate3D(12.495488442000067, 41.902603910000039, 59.504700000004959),
  new Coordinate3D(12.495461061000071, 41.902603910000039, 59.504700000004959),
  new Coordinate3D(12.495461061000071, 41.902603910000039, 62.552700000000186),
  new Coordinate3D(12.495488442000067, 41.902603910000039, 59.504700000004959),
  new Coordinate3D(12.495461061000071, 41.902603910000039, 62.552700000000186),
  new Coordinate3D(12.495488442000067, 41.902603910000039, 62.552700000000186),
};

var coords_face6 = new List<Coordinate3D>()
{
  new Coordinate3D(12.495488442000067, 41.902603910000039, 62.552700000000186),
  new Coordinate3D(12.495461061000071, 41.902603910000039, 62.552700000000186),
  new Coordinate3D(12.495461061000071, 41.902576344000067, 62.552700000000186),
  new Coordinate3D(12.495488442000067, 41.902603910000039, 62.552700000000186),
  new Coordinate3D(12.495461061000071, 41.902576344000067, 62.552700000000186),
  new Coordinate3D(12.495488442000067, 41.902576344000067, 62.552700000000186),
};

// materials
var materialRed = new BasicMaterial();
materialRed.Color = System.Windows.Media.Colors.Red;

var materialTransparent = new BasicMaterial();
materialTransparent.Color = System.Windows.Media.Colors.White;
materialTransparent.TransparencyPercent = 80;

var blueTransparent = new BasicMaterial(materialTransparent);
blueTransparent.Color = System.Windows.Media.Colors.SkyBlue;

// create a list of patch objects
var patches = new List<Patch>();

// create the multipatchBuilderEx object
var mpb = new ArcGIS.Core.Geometry.MultipatchBuilderEx();

// make each patch using the appropriate coordinates and add to the patch list
var patch = mpb.MakePatch(PatchType.Triangles);
patch.Coords = coords_face1;
patches.Add(patch);

patch = mpb.MakePatch(PatchType.Triangles);
patch.Coords = coords_face2;
patches.Add(patch);

patch = mpb.MakePatch(PatchType.Triangles);
patch.Coords = coords_face3;
patches.Add(patch);

patch = mpb.MakePatch(PatchType.Triangles);
patch.Coords = coords_face4;
patches.Add(patch);

patch = mpb.MakePatch(PatchType.Triangles);
patch.Coords = coords_face5;
patches.Add(patch);

patch = mpb.MakePatch(PatchType.Triangles);
patch.Coords = coords_face6;
patches.Add(patch);

patches[0].Material = materialRed;
patches[1].Material = materialTransparent;
patches[2].Material = materialRed;
patches[3].Material = materialRed;
patches[4].Material = materialRed;
patches[5].Material = blueTransparent;

// assign the patches to the multipatchBuilder
mpb.Patches = patches;

// check which patches currently contain the material
var red = mpb.QueryPatchIndicesWithMaterial(materialRed);
//   red should be [0, 2, 3, 4]


// call ToGeometry to get the multipatch
multipatch = mpb.ToGeometry() as Multipatch;

var sr = MapView.Active.Map.SpatialReference;

var extent = MapView.Active.Extent;
var center = extent.Center;
var centerZ = MapPointBuilderEx.CreateMapPoint(center.X, center.Y, 500, sr);

// cube
multipatch = ArcGIS.Core.Geometry.MultipatchBuilderEx.CreateMultipatch(MultipatchConstructType.Cube, centerZ, 200, sr);
// tetrahedron
multipatch = ArcGIS.Core.Geometry.MultipatchBuilderEx.CreateMultipatch(MultipatchConstructType.Tetrahedron, centerZ, 200, sr);
// diamond
multipatch = ArcGIS.Core.Geometry.MultipatchBuilderEx.CreateMultipatch(MultipatchConstructType.Diamond, centerZ, 200, sr);
// hexagon
multipatch = ArcGIS.Core.Geometry.MultipatchBuilderEx.CreateMultipatch(MultipatchConstructType.Hexagon, centerZ, 200, sr);

// sphere frame
multipatch = ArcGIS.Core.Geometry.MultipatchBuilderEx.CreateMultipatch(MultipatchConstructType.SphereFrame, centerZ, 200, 0.8, sr);
// sphere
multipatch = ArcGIS.Core.Geometry.MultipatchBuilderEx.CreateMultipatch(MultipatchConstructType.Sphere, centerZ, 200, 0.8, sr);
// cylinder
multipatch = ArcGIS.Core.Geometry.MultipatchBuilderEx.CreateMultipatch(MultipatchConstructType.Cylinder, centerZ, 200, 0.8, sr);
// cone
multipatch = ArcGIS.Core.Geometry.MultipatchBuilderEx.CreateMultipatch(MultipatchConstructType.Cone, centerZ, 200, 0.8, sr);


// use the builder to add materials or textures
//   - create a cone with a material
builder = new MultipatchBuilderEx(MultipatchConstructType.Cone, centerZ, 200, 0.8, sr);

BasicMaterial faceMaterial = new BasicMaterial();
faceMaterial.Color = System.Windows.Media.Color.FromRgb(255, 0, 0);
faceMaterial.Shininess = 150;
faceMaterial.TransparencyPercent = 50;
faceMaterial.EdgeWidth = 20;

foreach (var patch in builder.Patches)
  patch.Material = faceMaterial;

multipatch = builder.ToGeometry() as Multipatch;

// Create BasicMaterial with default values
BasicMaterial material = new BasicMaterial();
System.Windows.Media.Color color = material.Color;         // color = Colors.Black
System.Windows.Media.Color edgeColor = material.EdgeColor; // edgeColor = Colors.Black
int edgeWidth = material.EdgeWidth;                        // edgeWidth = 0
int transparency = material.TransparencyPercent;           // transparency = 0
int shininess = material.Shininess;                        // shininess = 0
bool cullBackFace = material.IsCullBackFace;               // cullBackFace = false

// Modify the properties
material.Color = System.Windows.Media.Colors.Red;
material.EdgeColor = System.Windows.Media.Colors.Blue;
material.EdgeWidth = 10;
material.TransparencyPercent = 50;
material.Shininess = 25;
material.IsCullBackFace = true;