private static Model BuildPlane(System.Drawing.Color material)
{
var assembler = new Assembler {
Color = material
};
assembler.AddVertex(-1, 0, 1);
assembler.AddVertex(1, 0, 1);
assembler.AddVertex(1, 0, -1);
assembler.AddVertex(-1, 0, -1);
assembler.CreateTriangle(0, 1, 2);
assembler.CreateTriangle(2, 3, 0);
return(assembler.Compile());
}