# How to Judging a point is on the front side of the Earth, not is the back side?

How to Judging a point is on the front side of the Earth, not is the back side?
Help, Thanks!

Hi @ranxie,

I’m not sure what you mean by the “front side” or the “back side” of the Earth. Can you provide an image that explains what you mean?

America is on the front side of the earth， Asia is on the back side of the earth。
How to Judging a point is on the front side of the Earth, not is the back side?

Hi @ranxie,

I don’t know what your use case is. How is the point on the Earth being obtained?

As a generic answer, maybe you can try using the `LineTraceByChannel` function as explained here. If a line hits something, you can get the normal vector at the point of impact. This vector points perpendicular to the surface of whatever got hit. You can use this vector to test if it’s a location on the Earth that is facing towards or away from the user. The “front side” and “back side” of the Earth will change depending on where the camera is looking, so you would need to compare this to the camera’s view vector.