@Prodipo, let me expand on what @syntheticmagus said about the file formats.
.hdr is one of the few file formats that has an option to store 32-bit data which is necessary for high dynamic range. The
.dds file format is one of those options for 32-bit data, but also allows storage of mip-maps which is how we simulate roughness in our PBR rendering. Rather than calculating a specular lobe from the roughness value of a surface and sampling and averaging many pixels from the IBL, we instead correlate the roughness level with a particular mip level and do a texture look up from the
.dds. This is much faster than all of the extra calculation which is a must for rendering on low end devices.
In your normal asset creation workflow, you would continue to use
.hdr files in your DCC tools. The
.env format is specific to Babylon IBL for rendering. The
.dds format can be used for either cubemap environment lighting or simply as compression for your model textures. If you are looking to compress your model textures, you can use the
.dds format and a tool like the Nvidia Texture Tools Exporter can compress your textures in either a stand alone app or a plugin for Photoshop. Syntheticmagus is right in that the
.dds format is not the easiest to use as the tools to save and open it are limited.
For environment IBL, you will always need to pre-compute your
.hdr to align with our PBR calculations using Lys, preferably as it matches exactly with our algorithm. IBLBaker can also be used, but is not an exact match for our algorithms. In a pinch it can work, but the lighting will be slightly different though may still be acceptable. The link you mentioned do contain the exact steps in each software to do the conversion. Unfortunately, there just aren’t more options out there than these two that we have found that can work.
If you have specific questions about the conversion process in those two packages, I can help answer them, but start with that documentation page as your first stop. Those will get you to the
.dds file and then further down the page shows you how to use our inspector to save out an 8-bit RGBD
.env file which will save you a lot of file size to speed download. Realize though, that you won’t be able to easily open that
.env file for edits as it is basically an optimization only for file size so will only work for rendering in Babylon.js.
The best workflow is to keep your
.hdr source file for edits and pass any iterations through Lys or IBLBaker and then convert to
.env in the Babylon.js inspector each time you need to make a change. This will give you the best results rather than trying to edit a pre-computed mip chain in the
.dds or deconstructing the