Imagination PowerVR SDK Blog

Cube Map Face Order


#1

Hello everyone,

I´m trying to use PVRTexLib for cube map compression, but can´t find any documentation on the face order. (e.g. +X -X +Y -Y +Z -Z) Also I´m missing information about how to set the surface number in the texture header. Is it one surface per face or is the library handling the whole cube map as one surface?

Kind regards and thanks in advance.



#2

Hi Joe,

The cube face order should be the following:
+y,-y,-z+z,+x,-x.

It should be noted that when compressing to an OGL format, these faces are shuffled into +X -X +Y -Y +Z -Z for deployment. The shuffled order is only for loading in the first place and for DirectX/OpenVG.

Whilst this isn’t strictly a bug; both DirectX and OpenGL use +X -X +Y -Y +Z -Z as a standard, so future versions of PVRTexLib will switch to using this as well.

Thanks,

Tobias