obi fluid + hdrp

[marad747]

Does obi fluid support hdrp render and waht me do if no? I need obi at hdrp pls help

[josemendez]

Does obi fluid support hdrp render and waht me do if no? I need obi at hdrp pls help

Hi,

Currently only built-in and URP are supported. We are working on HDRP support, but progress is very slow as there's basically zero documentation on how it works internally or how to hand-write shaders for it.

Any progress is made by reverse-engineering the HDRP to figure out how it works and bolting things one by one on top of it, in a trial-and-error fashion.

[marad747]

Hi. I can use HDRP + obifluid in VR project.
Dont perfect but work. I have problem, VR drawing at 2 eyes, and obi fluid rendered at left eye but dont rendered at right eye. How to fix it? I use settings from simple fluid exampleample.

[josemendez]

Hi. I can use HDRP + obifluid in VR project.
Dont perfect but work. I have problem, VR drawing at 2 eyes, and obi fluid rendered at left eye but dont rendered at right eye. How to fix it? I use settings from simple fluid exampleample.

Obi fluid is not compatible with HDRP yet. For VR, fluid rendering is not compatible with single-pass stereo rendering. You must use a separate camera for each eye. Both questions are answered in the FAQ:
http://obi.virtualmethodstudio.com/tutorials/

[zagoalie]

Is it possible to get a very rough estimate of when you expect obi fluid to work with HDRP? I am planning my next project and i would like to use both HDRP and obi fluid, so if its a few months kinds of thing then it will definitely be done in time for me, but if it's a year or 2 then I may need to look for other solutions.

[josemendez]

Is it possible to get a very rough estimate of when you expect obi fluid to work with HDRP? I am planning my next project and i would like to use both HDRP and obi fluid, so if its a few months kinds of thing then it will definitely be done in time for me, but if it's a year or 2 then I may need to look for other solutions.

Hi,

At this point it is unlikely it will be a few months, as Unity hasn't made available any kind of documentation on how to deal with and extend HDRP's shading pipeline and doesn't look like they will in the near future. This is currently the main bottleneck holding us back from adding HDRP support. We've tried to do this in the past by reverse-engineering the entire pipeline, but that got us nowhere.

Once there's more documentation available, I suppose a few weeks should be enough to implement HDRP support, but again this isn't entirely up to us.

[ibbybn]

Hi,

At this point it is unlikely it will be a few months, as Unity hasn't made available any kind of documentation on how to deal with and extend HDRP's shading pipeline and doesn't look like they will in the near future. This is currently the main bottleneck holding us back from adding HDRP support. We've tried to do this in the past by reverse-engineering the entire pipeline, but that got us nowhere.

Once there's more documentation available, I suppose a few weeks should be enough to implement HDRP support, but again this isn't entirely up to us.

Would love to get the fluids in my hdrp project also.
Have you taken a look at Jason Booth's Better Shaders already?
He just released a publisher workflow video for his 'meta' shader which converts to all pipelines:
https://www.youtube.com/watch?v=LFeVETnxm08
Perhaps this could speed things up.

Here's an overview: https://www.youtube.com/watch?v=eEUT-7ObapQ

[MostHated]

Edit - - My bad, I wrote that whole thing not realizing the fella above me said the same thing, lol.

Hey there,
    Have you guys looked into Jason Booth's "Better Shaders"? From what I understand, he wrote a new shader framework in which you write a shader once and it automatically creates the standard, URP, and HDRP shaders, without all of the "what the??" that the current SRP shader system has.

https://assetstore.unity.com/packages/to...drp-187838

I am no shader expert, so I don't know if Obi's shaders count as "surface shaders", but it does say this:

"If you've ever looked at the source to an HDRP shader graph shader and thought "12,000 lines of shader code, for a shader that just has a simple texture? What is all this?" then this is the asset for you. You can easily port Surface Shaders to Better shaders in minutes, and then use those shaders in any render pipeline. Code is written in standard HLSL, with a unified API across all 3 render pipelines, so you can write code and not worry about compatibility anymore. "

I do know that a few assets, such as Vegetation Studio Pro, are coming out with new updates that are going to be using this framework for their shaders, and I hear nothing but good things. Perhaps it might be of use?

I bought Obi Fluid over a year ago in hopes to be able to use it in my HDRP project instead of having to try and do blood in Houdini, export to Alembic, try and get things lined up so that it lands where it needs to land, etc. It has been a *huge* PITA. I would love for the HDRP version to come out! I see that it at least sort of renders now, there Is just no color for me. So fingers crossed it is fairly soonish. : )

Thanks,
-MH

[josemendez]

Hi there,

Obi's fluid renderer is quite unconventional. The technique it uses is called screen-space ellipsoid splatting. The closest relative I can think of is a deferred renderer: particle properties (depth, thickness, color) are splatted to a full-screen buffer, and smoothed out. Then normals are extracted from depth, a surface extracted from normals+depth+ thresholded thickness, and a final pass shades it. It all happens in screen-space.

I'm aware of Jason's frustration-fueled advances in providing a surface shader-like abstraction on top of all SRPs (which should have been a core, built-in part of the SRP architecture if you ask me), but I don't think they will help us in any way given that actual surface shaders didn't either. The fluid rendering pipeline unfortunately cannot be expressed as a surface shader.

Now that Obi 6.0 is out and stable, I will start round 2 against HDRP's shading pipeline and see if I can make sense of it all. Can't make any promises though. 

[tepat]

Hi Jose !

So do you succeed to make it work in HDRP ?    
We are really interested here !
keep up the good work !
Thanks !!