Unity Billboard Demo

Note: this project uses Unity 4.6.1. Created to answer this question.

It has 3 scripts:

• Rotate: on the sphere. It rotates the sphere.
• BillboardToCamera: on each Canvas. Makes them always face the camera.
• FadeAlphaByDistance: on each Text. Makes them fade out when they're far from the camera. Caveat: have to manually set minDistance and maxDistance, values which represent the text's minimum and maximum distances from the camera. Uncomment Debug.Log(distance) and watch the console in the editor to get a sense of appropriate values.