HDRI Detection and Grouping

Gaffer's HDRI Handler attempts to figure out which HDR files are variations of the same image, such as different resolutions, blurred versions, etc. This allows you to have a clean list of HDRIs in Blender without any duplicates - you simply choose the HDRI you want, and then choose the resolution/variation.

Grouping the files together can be tricky, since most photographers who create HDRIs have their own system of naming their files and it's impossible to detect and support every such system.

Gaffer works by finding the last separator character (_, -, . and spaces) in the file name and thinking of everything before that as the base name, and everything after that as a kind of variation.

For example, here are some files:

• pretty_sky_01_2k.hdr
• pretty_sky_01_16k.hdr
• pretty_sky_01_blur.hdr
• abandoned-interior-large.exr
• abandoned-interior-small.exr
• sunset-4k-01.tiff
• sunset-8k-01.tiff
• sunset-4k-02.tiff
• sunset-8k-02.tiff

Gaffer will group those files like this:

• pretty_sky_01 with variations 2k, 16k and blur
• abandoned-interior with variations large and small
• sunset-4k with variations 01 and 02
• sunset-8k with variations 01 and 02

The first two HDRIs (pretty_sky_01 and abandoned-interior) are detected fine, but the last two are not because their file names are misleading: the resolution of the file (4k or 8k) is in the middle of the HDRI name. If they were named like sunset-01-4k instead of sunset-4k-01, they would have been grouped properly.

It's impossible for Gaffer to support every possible combination of naming conventions, so it's up to you to make sure the files are named properly.

You can see a list of files and how they are grouped together in the User Preferences:

If you have a lot of files to rename, look for a batch renaming program to help you out. On Windows, I'd recommend the Bulk Rename Utility.