/// <summary>
        /// Creates a <see cref="Mesh3DGroup" /> from the loaded file.
        /// </summary>
        /// <returns>A <see cref="Mesh3DGroup" />.</returns>
        public Mesh3DGroup CreateModel3D()
        {
            Mesh3DGroup modelGroup = null;

            modelGroup = new Mesh3DGroup();
            var g  = this.CreateMeshGeometry3D();
            var gm = new Object3D
            {
                Geometry = g,
                Material = this.DefaultMaterial,
            };

            modelGroup.Add(gm);
            return(modelGroup);
        }
        /// <summary>
        /// Builds the model.
        /// </summary>
        /// <returns>The model.</returns>
        public Mesh3DGroup ToModel3D()
        {
            Mesh3DGroup modelGroup = new Mesh3DGroup();
            int         i          = 0;

            foreach (var mesh in this.Meshes)
            {
                var gm = new Object3D
                {
                    Geometry = mesh.ToMesh(),
                    Material = this.Materials[i]
                };
                modelGroup.Add(gm);
                i++;
            }
            return(modelGroup);
        }