Now we need some floor shadows in our scene. Create a floor plane that is large enough to capture shadows in the scene.
Shadow Matte
Create and assign a shadow_matte shader to the floor plane.
Image Plane
Select the render camera and under 'Environment', create a new image plane. Open the photographic backplate within the image plane as below. In this example, we will be using '103.jpg'.
Open image plane in Maya
Render the scene. You should see the spheres rendered against the image plane with a shadow created by the shadow_matte shader.
If the reflections appear incorrect, rotate the skydome_light until it matches the backplate.