Outputs, and using them
The project's formats lists what render writes:
| Format | Files | |
|---|---|---|
exr-faces | NAME_px.exr .. NAME_nz.exr | linear HDR, half float, the faces |
exr-equirect | NAME_equirect.exr | linear HDR, equirectangular |
ktx2 | NAME.ktx2 | linear HDR cubemap, RGBA16F, loads into GL or Vulkan as it is |
png-faces | NAME_px.png .. NAME_nz.png | 8-bit, display-referred |
png-cross | NAME_cross.png | 8-bit, a horizontal cross |
png-equirect | NAME_equirect.png | 8-bit, equirectangular |
The HDR is the sky itself, unclipped: take it if your engine tonemaps. The PNGs are derived from it through the display curve the look was designed on.
Directions
Faces follow the GL cube map convention every engine's cubemap loader uses (px nx py ny pz nz, first row at the top). The cross is laid out -x +z +x -z across,
+y above +z, -y below. The equirectangular map is centred on +z, with +x
a quarter turn to the right and +y up.
Orientation and the key light
yaw, pitch and roll in the project's [orientation] turn the sky on export:
positive yaw carries +z toward +x, positive pitch +z toward +y, positive
roll +x toward +y.
Beside the images, NAME.json gives the key light -- the light the sky's form
is lit by -- as a direction, as azimuth and elevation, and as light_travels:
point your scene's directional light that way and it agrees with the sky. The sky
has no sun in it; your game adds its own.