How to Inject .HDR textures - matyalatte/UE4-DDS-Tools GitHub Wiki
[!Warning] This is an old method. The tool supports
.hdrnow!
UE4 uses BC6Hu (not BC6Hs!) as the format for HDR textures.
But most texture tools do not support it.
The only confirmed method is the one introduced here.
0. Requirements
* We can't use other texture tools. I haven't test all tools, but at least, GIMP and Paint.net won't work.
1. Edit .hdr
Edit .hdr with Photoshop.
* I don't have PS, so can't explain how to edit.
2. Make a Batch File for texconv
We will convert .hdr to BC6Hu with texconv.
But it doesn't support GUI.
So, we need to make a batch file to run it first.
Copy the text below and save as to_BC6Hu.bat with notepad.
@echo off
@if "%~1"=="" goto skip
@pushd %~dp0
texconv.exe -f BC6H_UF16 -y "%~1"
@popd
pause
:skip
Then, put the .bat into the same directory as texconv.exe.

3. Convert .hdr to BC6Hu
Drop .hdr onto to_BC6Hu.bat.
BC6Hu texture (.dds) will be generated.
4. Inject .dds
Inject the .dds with my DDS tool.
We won't get warnings about the format.