Bug: some volumetric model are dimmer than DX8

[kiddu25]

Describe the bug

As you can see, models such as vol_light128x256 start to be buggy when with the DX9 version of Half-Life 2 has been out.

So the issue might be whether it's possible to make the DX11 models work as expected, just like they do in the DX8

renderer.DX11(p2ce) :

DX8(HL2) :

To Reproduce

1.open hl2 with steam launch option (+mat_dxlevel 80) and p2ce
2. open d1_trainstation_02
3. Compare the results

Issue Map

1. any with these types of model but it's d1_trainstation_02

Expected Behavior

1. volumetric should be more louder

Operating System

windows 11

[GrubPL]

From what I remember hearing
DX9 is the main way HL2 is meant to be played, it was there since launch last I checked
And the DX8 mode that is there is just DX9 with features disabled, at least that's what l I've heard from Misyltoad (the contractor behind bringing TF2 code to the 2013 SDK)

If I has to guess, DX8 mode is the one that's producing unintended visuals, not DX9

[kiddu25]

even on DX9 seem like it's dimmer on sdk2013 that it's was on launch hl2 version (seem like strata source one
and seem like on DX11 is even less visible than DX9)