Custom post-processing effects with new HDRP workflow

I tried following this tutorial that stated that the effects would work with the new Scriptable Render Pipelines, but I can't seem to find the effect under my Scene settings object with a Volume script.

https://github.com/Unity-Technologies/PostProcessing/wiki/Writing-Custom-Effects

Is it still possible to write custom image effects with the new workflow and if yes, what am I missing?

 

Hi, I am in desperate need for custom post processing effect too.
In roughly which iteration of the 2019.3a will the custom post processing be supported?

 

Hi remi,

Given 2019.3 is already in alpha, can you please expand on how custom effects implementation will (broadly) require changes? I assume you guys already have an idea, and any information you can share would be greatly appreciated by the number of developers who create third party post-processing effects for users.

 

Hi , any updates on this ? i am currently looking to implement my own custom effects but seems like the new way doesn't allow to access the classes needed due to protection level , i tried inheriting from the "VolumeComponent" class but it only adds the custom effect's name and doesn't expose a "Render" function to override to do the stuff needed , any kind of info would be appreciated

 

I am also in the desperate need of custom post processing in hdrp in 2019. Can we please get an update or some info at least?

 

Just posting to add my voice to this. I want to make a custom post-processing effect with the new HD Renderpipeline. But I don't really know where to start. Are there any tutorials on how to work with custom post-processing effects in HDRP?

I'm guessing that is what Remi means by they are working on it for 2019.3. Unity doesn't have the "infrastructure" to customize the post-processing effects yet?

 

This is currently a huge hole in HDRP and keeps it from being a serious system for game development. Without custom post-process capability HDRP will remain nothing but a shiny toybox.

 

I posted it elsewhere but Keijiro has come up with a technique. Not sure where on the "sane" to "hacky" spectrum it sits: https://github.com/keijiro/HdrpAovTest

Any official word from Unity on whether this is good way forward would be nice. (any official word on post processing would be nice right now)

 

In case that anyone needs custom post processing & hdrp in 2019.X - I wrote small step-by-step tutorial how to achieve this by actually modifying the pipeline itself: https://medium.com/another-angle/custom-post-processing-using-hdrp-in-unity-2019-x-60302a2fa1e0

 

Thanks @nehvaleem !

 

It doesn't look like its implemented in 2019.3b (beta). Are we sure this is coming in 2019.3? Or has it been pushed to a later release?

 

Yeah, I would like to know as well. I dont' like the fact that it has not been mentioned in any release log yet.

 

@remi_unity163 Any news on this one? Will custom pfx be available as the HDRP goes out of preview?

 

I managed to get it working this morning: https://github.com/IxxyXR/HDRP-Custom-Post-Processing-Test

I had to edit manifest.json to get the next version 7.1.1 of HDRP a bit early and comment out a block of XR related code that was causing an error - but custom PP works in HDRP as of today!

 

Any documentation?

 

I belive it is using custom passes that recently were merged into hdrp on github. More info is available here: https://github.com/Unity-Technologies/ScriptableRenderPipeline/pull/4317

 

I'm not entirely clear myself at the moment (I'm writing this from memory as I'm not near my Unity laptop now) but I think Custom Passes are slightly different from Custom Post Processing Effects with the latter being slightly simpler to set up.

Here are the three files to refer to in my repo:

https://github.com/IxxyXR/HDRP-Custom-Post-Processing-Test/blob/master/Packages/manifest.json

https://github.com/IxxyXR/HDRP-Custom-Post-Processing-Test/blob/master/Assets/NewPostProcessVolume.cs

https://github.com/IxxyXR/HDRP-Custom-Post-Processing-Test/blob/master/Assets/New Post Process Shader.shader

Procedure was something like:

1. Edit manifest.json to reference 7.1.1 of "com.unity.render-pipelines.high-definition" and "com.unity.shadergraph" as that version doesn't currently show up in the package manager UI. After Unity finishes loaded those packages find there is an #if block in one of the scripts that might throw an error - I just commented it out for now as it was XR related

2. Right click and create a new Post processing script (it's a specific option in the create menu) and a PP shader (or use the scripts in my repo as an example). Check the shader references the script name correctly (see line 21 in mine)

3. Go to Project Settings/HDRP Defaults and scroll down to the bottom. Add the effect to the section (
Before Rendering/Before Transparent/Before PostProcess) that corresponds to what you put in your cs script (see line 16 in mine)

4. Add a Volume in your scene. Your effect should now appear in "Add overrides" as a new item under Post Processing/Custom

I think this should work on 2019.3 but I used the 2020 alpha.

I'll try and remember check this later for accuracy and edit if I've missed a step.

 

2019.3b4 is now out and with it HDRP 7.1.1 now appears in the package manager: https://docs.unity3d.com/Packages/c....high-definition@7.1/changelog/CHANGELOG.html

"Added Custom Post Processes with 3 injection points: Before Transparent, Before Post Process and After Post Process"

I'm just testing it works as expected now (waiting for the damn shaders to compile!)

 

Great news, is this same as custom forward render structure in LWRP ?

 

Don't think so. This is very specific to post-processing. The custom renderer stuff in URP/LWRP seems broader (although to be fair I don't currently quite understand what it's capable of)

 

Ok, thanks for the info, i hope porting effects will not be hard

 

There is separate Custom Pass on HDRP now as well.

 

@andybak is there anything specific this setup needs? I just started digging more into HDRP and dl'ed your example, which seemed to work fine, saw the depth step effect. However, now that I created a new shader and post effect via the menu in a new Unity project in 2019.3.0b6, nothing seems to happen. I've been looking at your scene and settings but so far I haven't managed to figure out what is the reason that nothing happens. Copied your files over to the project and the same result, nothing happens. I wonder if it's the HDRP version, HDRenderPipelineAsset settings or what exactly that causes this to fail.

 

Ok, now I got it. The very last place where I checked was the solution. You have to add the custom effect in the "Custom Post Process Orders" in HDRP Default Settings. I'd imagined if such list exists, they would go there automagically as they did with Stack v2 in 2018. Oh well. 1.5 hours wasted...

 

Yeah. That was the bit that held me up for the longest time too. (I did mention it in my post above as point 3.)

 

Too bad I missed it.

 

It was surprisingly painless to convert a few Stack v2 effects to this new setup, but still quite frustrating as too many things require using new this and that... I spent hours just trying out stuff to see what works. And that HDRP documentation is somewhat lacking for novices like myself. Hard to guess if I've done something totally wrong or not.

 

have you maybe ported v2 bloom using new setup?

 

To avoid confusion, meant my own effects. But I don't think it would be that hard to create almost similar/clone of the old bloom. That new one does not look good.

 

Keijiro has just updated Kino for HDRP: https://github.com/keijiro/Kino

 

These are very simple effects and there is a tone of stuff missing! Where are the DOCS? How do we generate 'World space normals! ' , how to access motion vectors, These are all rudimentary to say the least.

 

You can find HDRP documentation at:
https://docs.unity3d.com/Packages/com.unity.render-pipelines.high-definition@6.5/manual/index.html
And scripting API documentation here:
https://docs.unity3d.com/Packages/com.unity.render-pipelines.high-definition@6.5/api/index.html

Yes I know, they are not leading you by the hand but I think you can already find some solid information there, if you want to get started with HDRP. At least you see what methods are available and so on, if not clearly stated purpose for each thing (which is something I too would like to see.)

 

@LIVENDA_LABS was specifically talking about custom post-processing - and he's right - there is currently no documentation on that.

Although to be fair it's only been out for a couple of weeks. (Not sure that's really an excuse. For most software "not having docs" is a blocker for release)

 

Well yes, but the entry point is probably the issue if you want to get started (i.e. how to get your stuff to screen, even if it's just an invert color effect.) And I too am wondering why the documentation is what it is...

 

Spent this afternoon converting the old bloom to HDRP, it's definitely doable, got it working already. I think I got a few small glitches still as I really don't know what all the macros do that existed in that v2 version.

 

Can anyone help us get worldspace normals (not normals generated from depth) and motion vectors with the new HDRP PP pipeline would be greatly appreciated

 

@LIVENDA_LABS I did some digging last night... Just in case you still need help with this issue. I'm interested in developing HDRP content too so I thought I'd take a look.

I did some source code reading, looks like DebugViewMaterialGBuffer.shader file has interesting information and same goes for ScreenSpaceReflections.compute. I just used Notepad++ and did file search in the HDRP package folder for words like 'normal'. Very handy. Then just search for these files inside HDRP package folder. Anyway;

When you got your default volume effect and shader templates ready, include:

Code (HLSL):

1. #include "Packages/com.unity.render-pipelines.high-definition/Runtime/Material/Material.hlsl"
2. #include "Packages/com.unity.render-pipelines.high-definition/Runtime/Material/Lit/Lit.hlsl"

Then, you find GetNormalAndPerceptualRoughness method in the ScreenSpaceReflections.compute.
You can rip out the stuff you don't need but now you should be able to access normals.

Just tried it out and I got the normals on screen.

The motion vectors are then the next thing to tackle... Hope this helps?

 

@LIVENDA_LABS ScreenSpaceReflections.compute has also a section:

Code (HLSL):

1. float2 motionVectorNDC;
2. DecodeMotionVector(SAMPLE_TEXTURE2D_X_LOD(_CameraMotionVectorsTexture, s_linear_clamp_sampler, min(hitPositionNDC, 1.0f - 0.5f * _ScreenSize.zw) * _RTHandleScale.xy, 0), motionVectorNDC);

It looks like this provides motion vector data? I got something to my screen when I set camera to spin around an obj.

I'm not sure if I did it correctly, but I can't invest more time into this at the moment. Anyway, I just replaced hitPositionNDC with input.texcoord and then I got this blue/cyan and purple thing on the screen which I suspect might look correct.

And depth (even if you didn't need it atm) you can get with:

Code (HLSL):

1. // Get depth
2. float depth = LOAD_TEXTURE2D_X(_CameraDepthTexture, positionSS).r;

 

I know I'm probably talking to a wall here, but can anyone at Unity ( @remi_unity ?) actually give us developers some clarity as to how "locked" the API is at the moment?

Right now, anyone wanting to develop a maintainable post-processing system in HDRP has Keijiro's hobby project to go off, no official documentation, no other word from Unity on what will change, when it will change, etc. And forgive me for having to ask, but for a developer such as myself who maintains a 2000+LoC full post-pro subsystem, given Unity's track record of changing their PP API every time the wind changes direction, I'd like to have some clarity, as I'm sure other asset developers would.

I also don't see how Unity can be happy with the extensibility of HDRP post-processing in its current state, which is why I fear it will be changed again. @SebLagarde said the new post-processing allows for "better integration with PBR", "better quality", "better memory usage", "better performance" - but quite frankly, the design of the new C# effect-authoring side of post-processing is garbage. A 3000 LoC blob is Unity's idea of a modern, extensible post-processing system? How on earth does having to wade through 43 references to vignette in a C# file until you finally find the correct method 2000 lines down make sense, for those who want to tweak it? We are talking about the simplest effect in post-processing, something that could be achieved in Unity 4 or 5 in literally six lines of C# and a pixel shader, for the same quality, same memory usage, and same performance - and now it's part of this inextensible monstrosity. How is that a step forward?

David Helgason's ethos back when he was CEO was for Unity to democratise game development, to save developers time and let us focus on actually making stuff. This new HDRP stack goes completely against that. Writing effects takes longer. Editing existing effects is source control suicide. Hell, developers can't even write one effect once and have it work on mobile (URP) and HDRP - how is that a benefit for anyone?

 

This whole thing is one step forward in versatility and like a million steps back in every other way imaginable from what i see so far, the only hope is that they keep the standard pipeline and not force this new exponential complexity to every project, at least until is mature enough

 

The whole point of extending this from Unity's perspective is that they expose the injection points for custom passes and postprocessing passes. You are not meant to go tweaking existing effects unless you really can't do without. I dunno if there's ever been a game engine that would let you do what you are suggesting here (making each PP effect extendable out of the box). But even if you do need to tweak these effects, modifying the existing HDRP PP isn't THAT hard. It's just that since it's integrated, it does mean you have to mod it in the HDRP package.

Docs for the Custom PP and Custom Passes:
https://docs.unity3d.com/Packages/c...ml?subfolder=/manual/Custom-Post-Process.html
https://docs.unity3d.com/Packages/c...index.html?subfolder=/manual/Custom-Pass.html

 

Thanks for the docs links - if nothing else, the detail they've put into these makes me slightly more confident Unity won't throw out the current system in the very near future!

 

Does custom effects work at all? I've a similar issue with LWRP and Android as described in this thread.
Thank you in advance for your reply

 

They do work just fine if you write them for HDRP. But you can't use post processing stack v2 effects with HDRP.

See the documentation, it explains majority of the details quite well:
https://docs.unity3d.com/Packages/c...efinition@7.3/manual/Custom-Post-Process.html