How to modify the far edge of light

[lozn00]

Drift to the edge of the time when the transparency is gone, and I want a variety of, I do a boat slide in the fall of the effect of sliding. That the distance is not so wide, so it is not full screen.

[lozn00]

你看的懂中文，我就说了哈，就是是这样的比如我控制高宽为500 ，那么到边界的时候直接透明消失，不然很丑。能不能弄成这样的呀，怎么弄呢。

[lozn00]

另外就是控制颜色了。做船水花飘动效果 感觉你这个很适合，只要稍微把边界问题以及透明度还有灰色白色 弄一下就可以做我这个了。