HDRI images need to follow a special naming convention so the correct transformations can be applied on load.
DELTAGEN supports two types of HDRI images: Longitude Lattitude and Vertical Cross.
Longitude Lattitude images look like panoramic images unwrapped from a sphere with increasing distorsion on the top and bottom parts of the image. This is the most commonly used HDRI type. To be properly interpreted by DELTAGEN they use the suffix “_LL” in the filename (e.g. example_LL.hdri ).
Vertical Cross images combine one picture per viewing direction (top, bottom, left, right, front, back) into a single picture. They look like an unfolded cube and unused areas are black. These images need to use the suffix “_VC” or “_ZVC” in the filename (e.g. example_VC.hdri ).