Eye Shading Model renders Emissive unexpectedly when using a FloatRGBA scene format

This appears to be caused by the colour format. It only occurs when the scene format has an alpha channel. FloatRGB (format 3) doesn’t exhibit these issues. Unfortunately, format 4 is the default for Epic and Cinematic engine scalability.

1. Create two spheres
2. Create a material using the eye shading model
3. Add a 1,0,0 emissive to it
4. Apply it to a sphere
5. Create another material, set it to use the default lit model
6. Add a 1,0,0 emissive to it
7. Apply it to the other sphere
8. r.SceneColorFormat 4