How to fix the HDR Lightning problem.

There must be at least ONE light on the map in the HAMMER program

It need to be any type of light. [Eg. : light, light_spot ]

Your map MUST NOT contain any LEAKS

A leak occurs when a prop or displacement is not separated from the void. [The part that surrounds the entire map.]

Use Hammer++ to detect leaks and to preview the lights on the map that you've set up in Hammer.

I've noticed that Hammer++ doesn't generate HDR meshes even when the HDR option is selected, which is why SFM doesn't detect them. In that case, you need to use the OLD, standard version of Hammer. In that version, selecting the HDR option works without any issues.

It's pretty simple—you'll need to use the BSP Source program to unpack the map.

And follow the steps outlined above in the guide.

DevWiki BspSource

Download[github.com]

Open BSP Source and select map that u want. Before u hit decompile button go to OTHER
and select Extract embedded files. [ This option allows to extract custom models textures.]

https://www.youtube.com/watch?v=slJvCLQhoQI&t=197s

https://www.youtube.com/watch?v=JqxgYuEyc8s

I used my two different maps as examples.

Thanks for checking out my guide. I hope someone finds it useful!