Texture Coordinates in a Cube Map

[mshukun]

Thank you very much for your reply. I would like to draw all vertices onto each cube face image and then save them as new image files (in order to record and display where a user throws a ball in a 360 degree interactive environment). By analogy, in Google maps one can create place marks and store it as an image file. In my case, I am trying to perform the same essential function in a cube map (since place marks are added using HMD, users freely look around and add place marks onto 360 panorama images). All place marks x, y and z coordinates are then stored in database to populate all place marks and save them as a new image file for each face for later analysis -- at least that is my goal of what I would like to accomplish.

I would like to apply 2D texture coordinates (s and t) instead of 3D so I was thinking bottom left [0,0], bottom right [1,0], top left [0,1] and top right [1,1] for each face image should serve my needs, and I thought this would be the default texture coordinate system for a cube map, but it appears I was incorrect. Therefore, how do I set 2D texture coordinates for a cube map? I suspect the answer will require considering axis direction (e.g. Positive X : -Z(s), -Y(t), Positive Z: +X(s), -Y(t) and so on).

I believe finding the texture coordinate is the best method to achieve my purpose, but if you have any suggestion or guidance, it would be greatly appreciated.

Thank you again.