//sceneRoot.marsMatrix = sceneRoot.resetMatrix(sceneRoot.marsMatrix)
                var matrix = Qt.matrix4x4()
                matrix.translate(Qt.vector3d(mars.x, mars.y, mars.z))
                matrix.rotate(mars.tilt, tiltAxis)
                matrix.rotate(mars.roll, rollAxis)
                matrix.scale(mars.r)
                return matrix