What is Going On With This Depth Buffer?

[OnlyTaffingCowardsHide]

Specifically around fires and torches in the game, they show up as strange cascading blocks/arrows in the buffer.

It's making it very difficult to apply Ambient Occlusion and Global Illumination effects without it looking weird on flames.

[stgatilov]

Depth is OK at the moment when it is copied into texture, so in-game SSAO works fine:

The heatHaze effect (more specifically material textures/sfx/vp3) is rendered without disabling depth writes, and we get this:

Nobody has ever thought about it, because this depth buffer will be thrown away.

Now, if you have some tool that hooks into the game and intercepts depth buffer at the end of the frame, then it has problems.

[datiswous]

What program is that?

[stgatilov]

22 minutes ago, datiswous said:

What program is that?

It is RenderDoc.
With r_useDebugGroups 1.

[OnlyTaffingCowardsHide]

9 hours ago, stgatilov said:

Depth is OK at the moment when it is copied into texture, so in-game SSAO works fine:

The heatHaze effect (more specifically material textures/sfx/vp3) is rendered without disabling depth writes, and we get this:

Nobody has ever thought about it, because this depth buffer will be thrown away.

Now, if you have some tool that hooks into the game and intercepts depth buffer at the end of the frame, then it has problems.

Oh neat, so can we disable depth writes for the heat haze without breaking things? 
The problem with the in game AO is that it's based on technology that is quite deprecated now, and could even be called performance heavy for what it is. It doesn't apply to nearly as many surfaces/crevices as MXAO, it's noisy/inaccurate, and it takes similar performance as running MXAO AND global illumination. That image I posted in the op is taken directly from MXAO's output before it is mixed to the frame. So you can see just how much lighting detail it's adding to the game, that's all ambient occlusion from the shader, just applied on top of the depth buffer.
Reshade can be heavy on Opengl, but I've since upgraded to an RX6600 and I'm seeing excellent results enabling modern shading techniques in TDM without significant performance loss. Not just better ambient occlusion but also global illumination, ambient light, and SMAA/Temporal AA solutions are available that work better and offer better performance. I can imagine higher end rigs can get 100+ frames no problem with Reshade and it does end up looking a lot better.
I'm ready to upload the mod but if there was something that can be done to fix this last remaining issue...

Edited April 20 by OnlyTaffingCowardsHide

[stgatilov]

I'll try to do something about it.

But I'll be away from computer on the next week.

[stgatilov]

@OnlyTaffingCowardsHide, I think it would be easier to add an internal cvar that would copy back depth from the copied texture into the depth buffer. The performance hit for extra blit should be minor, but it would be much more reliable that trying to block depth writes everywhere after the copy.

UPDATE: Actually, I'm not thinking whether TDM translucent materials write to depth or not. There might be reason to write depth even while rendering translucents...

[OnlyTaffingCowardsHide]

So i guess this isn't viable to fix?
Not a big deal I suppose, I've found some issues with the shaders being drawn over readables as well, so I suppose there are going to be some issues with immersion either way.
I'll release it as a proof of concept for now, and if people like it maybe some of the shaders/code can one day be integrated into The Dark mod directly.