Babylonjs在彼此的顶部加载两个图像，第二个图像是透明的

I am using babylonjs to load up two images. One is a standard jpg image and teh second is a png image with transparent background When i load both the image loads on top of each other but the jpg image doesnt show through the area that should be transparent. Anyone know how i can do this.I am using babylonjs to load up two images. One