HDRP Support

[TomGillen]

Wet Stuff currently does not support the High Definition Render Pipeline. There are a few issues that need to be resolved:

• An alternate gbuffer shader needs to be written, to account for the different gbuffer layout of the HDRP. The new layout is still compatible with how Wet Stuff works, and we can even continue to avoid most buffer copies with careful blend states.
• Rendering code will need to be updated to account for different gbuffer source textures.
• Wet Stuff needs to be hooked into the HDRP.

The final issue is the only major blocker here. Currently, the HDRP does not respect Camera.AddCommandBuffer, nor does it have its own equivalent API. We may need to submit our own PR to Unity to add this functionality ourselves. Alternatively, we may need to provide instructions for users on how to import the HDRP from source and make the modifications themselves, or fork the HDRP ourselves.

Forum thread regarding Camera.AddCommandBuffer: https://forum.unity.com/threads/hdrp-how-to-render-anything-custom.592093/

Updates

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[Tanshaydar]

May be a late update but what you're looking for is here:

https://github.com/Unity-Technologies/ScriptableRenderPipeline/pull/4317

It's already merged into 7.x

[martindevans]

Unfortunately that's not quite what we need (yet). The custom passes can only be injected into the pipeline at certain points and none of the currently supported points (Before Rendering, Before Transparent & Before PostProcess) are suitable for WetStuff - we need something after rendering to the GBuffer and before calculating reflections.

We talked to some Unity engineers at the Unite conference about this and they're not very keen on adding new points at the moment. Their view is that each new point in the pipeline reduces their future flexibility because they have to keep those points consistent - they couldn't rearrange the render pipeline without breaking passes injected at these points. They said that once HDRP is released fully stable they might consider adding more points.

[Tanshaydar]

I see, sorry then.

I really loved wet stuff plugin, and I want to use it in every project I have, but HDRP is a real dealbreaker at the moment. I hope it gets sorted out.

The link I provided solved a custom PP for my current project, so I thought it would solve it for wet stuff, too, but I should've considered the reflection pass too. I thought it just got it from reflection probe.

[martindevans]

Even if it's not quite what we needed, thanks very much for pointing it out to us! ❤️

[danilofaugusto]

Any plans to support URP?

[martindevans]

Unfortunately I don't think it's possible at the moment. The way that Wet Stuff works fundamentally requires a "Deferred" renderer, but URP is currently a "Forward" renderer.

According to the FAQ there are plans to support a deferred mode for URP. When that is released we might be able to support it (it depends on exactly how the deferred renderer is implemented, if we can access/modify the data needed to apply the effect).

[danilofaugusto]

Oh that's unfortunate. Thanks for the quick response :)

[Hoxydev]

2 years later still nothing on URP or HDRP .

[RuchirRajOld]

Why isn't HDRP supported yet? it has a Deferred renderer and there is also an LTS version available

[martindevans]

Unfortunately it's not as simple as HDRP having a deferred renderer. The renderer also needs to store information in a way that's compatible with the effect and available for the effect to modify in an efficient way. For a long time HDRP didn't allow access to that data, we think that it does now but we still need to investigate in detail.

We have another asset coming out soon. Our plan is that when that's released we'll start working on investigating WetStuff:HDRP in detail.

[StarChick971]

What about URP too? This is also a main blocker for most of new Unity projects...

[martindevans]

URP does support a deferred renderer, so in theory it's possible but the same caveat about efficient access still applies of course. We'll probably investigate URP support after looking into HDRP.

[slacker-jake]

Any chance this will ever be supported in URP and forward rendering?

[martindevans]

Unfortunately it almost certainly won't ever work with forward rendering - the way the effects works is by accessing and modifying the gbuffer (an important part of a deferred renderer). We'd have to come up with a completely new technique to work with a forward renderer.