Cube Mesh Improvement

I want to know if hiding/delete a face of a cube witch is not visible by the player will increase performance or it will slow down to frame rate because it need to calculate wich face are not visible…

It will slow down your performance. Changing a mesh dynamically has quite a bit of overhead as the new mesh data has to be uploaded into GPU memory each time you change something.

Apart from that a single cube consists only of 12 triangles. The GPU is designed to perform millions of calculations per frame. It’s optimised to execute the same instructions on a large amount of data.

Next thing is most shaders use backface culling. So all triangles that have a counter-clockwise winding order aren’t rasterized at all. So while the vertex shader does still transform all vertices into screenspace, those triangles that doesn’t face the camera won’t be drawn so no fragment shader will run for those triangles.