Skybox uses 1.7k Tris and 5.0k Verts even if occluded?

In Unity 5.0.0f4, if I start a new project, the empty default scene is listed as having the following in Stats: Batches: 2, Tris: 1.7k, Verts: 5.0k

(In an existing project, Batches won’t go below 6 in an empty scene. I’m not sure what causes the difference.)

Anyway, changing the camera’s Clear Flags to Solid Color reduces Batches, Tris and Verts to 0, so it must be caused by the skybox. However, if I use six primitives to enclose the camera in the middle of a hollow cube, the Stats remain unchanged (except that Batches increases).

My questions are:

  1. Why does the skybox need so many polygons?
  2. Is there a way to cull areas of the skybox that aren’t visible? (Or the entire skybox?)
  3. Is there any sort of simpler, high-performance skybox render method available for mobile development?

Thanks!

@Daniel-F Sorry i’m 2 years late, I know just the answers you’re looking for.

  1. the default skybox is a sphere with a procedurally created texture. Spheres are high in verts, so naturally an empty scene will have 5k verts used.
  2. I do not think that would work out well, you may need to write your own skybox shader to allow culling, but i do not currently know how that would work.
  3. I know that switching to a cubemap will bring verts down to 40, I’m working on a shader that makes the whole skybox a single color, so it takes up very little verts.
    Switching to a cubemap made my empty scene’s 70-80 fps go up to as high as 512 fps with nothing in it. Therefore, swithing to a cubemap would be the best skybox for mobile development.

You’re welcome-Zak Kaioken