Showcase HDRP Sponza, learning about HDRP

My "final" results here:

Old info (useful details)
Hi and good day.
Due to my latest HDRP project being damaged, i'm trying with this sponza scene that one guy from unity shared some time ago, i'm making little changes and trying to imitate a real photo i get from internet of the sponza palace.



Anyway, there are some things i do not understand:

1 - You can see in the original foto how light and color bounces (compare the original image with the following)



I'm trying to do that in unity but even with more bounces it does not work. Here is my attempt


Definitely not there. I had to fake it with lights which is not exactly good in all cases. Here is faked


Is not the same and is sutil because if i make the lights stronger then it looks very bad, but the effect i was looking for "is there". Yes i tried with reflection probes and even when i move the blend points to make it more smooth, it looks very flat. In fact i thing the lightmaper is making a very flat work, because the light is not bouncing (that is why i faked the bounce on the walls). So what can i do to make it work without faking it?

2 - The other thing that i do not understand is: When i clear or delete the lightmaps all the objects becames blue, like reflecting the sky, i look everywhere i changed the post proccesing effects for visual enviroment, sky, sky colors, probes, everything where a blue color is XD and is always the same. Is not a big deal but i want to know why is that.



Do you know something about it? what is your feedback?
Thank you...

 

UPDATE:
The SSGI is making a very decent work even in medium quality with a GTX1050, the effect is there with SSGI



I think the lightmaper is decent but without those bounce effects looks flat. Here is a front view without SSGI.

 

Not sure what you are trying to replicate but the materials and the colors are different and as such you will receive different results. Not to mention that it is not possible to make it the same with real lighting no matter what you try.

In 3d rendering and lighting, we manage to give the ILLUSION that it is the same. A convincing resemblance. But it obviously is not possible to exactly replicate the results of an unknown number of light rays interacting an unknown number of times though countless bounces with just some hundreds or thousands of samples. Not to mention the exact behavior of the materials. There is not enough computational power on our machines for that.

Another important aspect is, in HDRP, if your materials are not provided with all the correct basic data channels the lighting comes wrong. i.e. Mask needs to provide the correct metallness, smoothness, AO, etc. afaik, all Sponza models come with very basic textures. Usually just base/color, and rarely a few bump/normal maps.

 

Hi... I don't want to make a 100% identical image, i want to replicate the feeling, the lighting, light bounces, reflections and add my own thing, like the volumetric and bloom effect etc...

I'm not talking about infinite number of rays, i'm talking about rays bounces i do not know what 3d software you use for renders but in the one i use (lightwave) this is pretty basic stuffs, in fact i can replicate that effect with less rays, i don't even think about it when i make my renders, of course, those are 3d renders sorftware. I think is something i'm missing.

HI, I get it, thanks for the link

 

You got me fooling around with this scene.

In general you are right. The lightmapper creates a very flat GI result.
That has been my problem with Unity for a long time, and in my opinion, that is the main reason Unity lighting is inferior compared to Unreal. The GI solution is flat. Soft.

To improve it you need a lot of extra work with post-processing.

This is with a full stack of effects and plenty of tweaks.




This is without my exposure tweaks (default exposure)



Flat scene.
Just baked lighting and default effects. My starting point.

 

You see? i'm a 3d artist i make realistic renders and all that stuffs and that is something i can NOT just ignore for a lightmapper xD.
Your scene is not the same, you are using the new verion from intel (which is also good) i'm using an old version but i made some changes. But anyway it is the same problem, to achieve those effects i need to put other area and point lights and if you try with SSGI it makes a little better job which for me has no sense. It looks like the rays are not bouncing, something like unity is taking the light value to make an average illumination for the scene, for example, if you are using just 1 light (the sun light) it has no sense the amount of light in the area where the camera is, even with exposure settings, if you compare that area where the door is you can see that is not accurate. But maybe @pierred_unity can help us with this, he is a pro.

 

With 64 bounces we should definitely see more bounce lighting in that scene.
Especially in the gallery where the light comes through.

We do not know what they have done to optimize the performance of the lightmapper.
But it definitely does not work as expected. Perhaps there is a travel distance limit?

SSGI makes sense because it is a tool that was created for real time.
It is not perfect but works.

I am an old school 3D artist myself, and I have learned to work differently in offline 3D. These methods you mention we used them before GI was a thing, dome lights to produce soft lighting, second direct for bounces, fillers, negative point lights for dark spots etc. but real time with Unity requires a different approach. You should use the relevant tools provided for this kind of work not the methods you know from offline rendering. (Some can be used, and they work great, but others not so great.)

Unity is not an offline renderer, and these methods should be avoided as they are costly in terms of performance.

 

hahaha i was going to write that in my previous answer but i didn't because it would seen arrogant XD, but yeah exactly those are old school techniques, something that should be unnecessary by a modern game engine which is also baking lights xD and i said that about SSGI because is screen space and also in medium quality, so lightmaps should looks better it suposed to take geometries and color into consideration for bounces and bake better results than SSGI in medium quality lol it makes me laugh

 

In many cases, it works as expected.
But in this particular case for whatever reason it doesn't.
And that is for me a bigger issue. Stability of the features.
Working as expected, every time.

The way I typically work is, to light my scene in a way that the basic lighting is correct, then improve with the filters and effects, but this time the scene looks really bad and basic lighting is not helpful.

I suspect that even if I add all practical lights in my scene to help boost the amount of samples, and try to work in a typical ArchViz approach, it is not going to work.

 

now i have a question for you, how did you get the uv for the lightmapper? i tried with that sponza scene before and unity says that it does not have uv for lightmaps

 

Yes of course i'm aware of that but i do not thing that flash will affect so much the lighting back on that area where the sun is reflecting light and you are right is not a proper photo xD but to be fair, as i said before to @soleron who mentioned the same thing, i do not want a 100% replica of that photo, i want to achieve the ambience the lighting style, the bounces and reflections and my point is about the bounces of the light and the reflections on the wall and floor i can see that in any other photo but no in unity's lightmap. Maybe you don't understand my point, see the comparison on the images below, the white to black bar represents how the light is bouncing and reflecting on the wall.




So i do not think the asset is a problem here, i can do it with a 4 walls and a floor and still get the same lack of "bounces"(?), As a said before i'm not looking a 100% replica of a random photo, is not even about the color of the materials, is about the light.

Do not take me worng, i'm very proud of what i managed to do with my scene in 1 hour learning HDRP XD (the original scene looked very different and not good in my opinion) and yes i read all your answer and you are right, but something like that, i though it was basic stuffs for a lightmapper in a 2021 very popular game engine...
I can fake it that is not a problem at all for me i'm not gonna cry for that jajaja (in fact i already did it, see the 4 photo of my first post) but before, i want to know all the limitations, pros and cons of HDRP, also, you know @pierred_unity unity has many so many options and settings and i need to ask before try to reinvent the wheel, i mean i though maybe it was something i missed.

 

Valuable information in this thread, thank you!

 

I knew i was missing something! Thank you @pierred_unity you are really great...
Looks like it was the lightmap resolution (mine was at 28) now i have what i was looking for:
i take off the texture to make it more obvious

Now the bad news is that i use your Post processing values and it looks very different here i did not like it and then i forgot my values and now is a mess XD i need to reconfigure everything again to my liking but i'll do that later (and i'll also post the result here) BTW i think i'm using the same scene as you: https://github.com/radishface/Sponza i just changed some materials and hid some objects

yeah i saw that.. lol

i won't either

 

Ah ok, looks like you had barely done any preparation in the scene.

There are two ways to do that:

The Hard One: Properly unwrap each model that you plan to have lightmapped in your 3D application.
Make sure you are using UV Channel 2. (if you are using 3dsmax.)
This way you can have complete control over your Lightmap unwrapping.
Some claim it is the best, for most models I see ZERO difference just a lot of wasted time.

The Easy One: Use Automatic unwrapping in Unity.
(my favorite but in some complex models you need to tweak it a lot or even do it using the "Hard" method.)

After importing your model.
You can select all the models you imported, or even the entire building if you exported everything together.

In the inspector make sure you are in the Model Tab.
Scroll down and

1. Enable "Generate Lightmap UVs"
2. Depending on the complexity of your object, reduce the hard angle. (Default is 88.)
   Think of it as like 3dsmax Smoothing Groups. The more complicated the shapes, the lower angle. That results in your lightmap space breaking down into more pieces. For a box, 88 is great. For a complex sculpture, I choose around 30. It is the angle between two surfaces (i.e. polygons) that the program may consider as "continuous".
3. Match this value to the lowest amount you plan to use in your lightmap resolution.
   By default, it is 40, but in many cases, you do not need to have such high lightmap resolution. In low frequency spaces even 20-25 should be more than enough. For preview 5-10 is usually great. for final production it really depends on the scene.

This result is with Lightmap Resolution set at 10.



There is a way to interactively see the resolution of your lightmap changing as you tweak the Lightmap Resolution value. Do not make it too dense, after a certain point there is no ROI and just takes too long to produce lightmaps.

This way you can see the checker overlay that will help you understand how much you should increase your Lightmap Resolution. As you see in my case, LR value of 10 is not low.

If you have a GPU with at least 8GB RAM it is worth trying the GPU lightmapper.
It baked the lightmaps of my scene in 3 minutes. The CPU would take significantly longer.



As with offline 3D rendering, be careful if there are trees, do not make them static.

For that you will need to use other methods to apply Lighting data to the objects.
(i.e. Light Probes)

With a Lightmap Resolution of 40, you barely see any difference with all the effects on.



Although if you do not enable SSGI then you will need to increase this value.
Baking is important because there may be low spec machines that underperform with SSGI.

 

Another way Unity is better than using an offline renderer.
You can always create different configuration files of Post Effects and Sky setups and load them at will depending on your scene.

You didn't have to overwrite the old values.
You could have set up a brand-new configuration file for your Effects volume.
Switch between them and see which one you like best.

 

I was talking about the sponza from intel, which i guess is the fbx you are using, i tried that, it did not work so i keep working with the old one. Right now i'm using another fbx that one guy from unity shares some time ago and i change some textures.
I know how to use the "Generate lightmap UV" tool from unity, i also know how to create UV maps with my 3d software, that was not the problem about that point, my problem with that sponza fbx file is that it has its UVs but unity does not recognize it (at least not my version of unity) i'm using the Y-UP version.

You are maybe using: https://www.intel.com/content/www/us/en/developer/topic-technology/graphics-research/samples.html

I'm using: https://github.com/radishface/Sponza

IF you are talking about creating your own UV for lightmaps, trust me it is better if you make them, i had a lots o problems some months ago for that with my actual project and it is a low poly game -.-"
https://forum.unity.com/threads/lig...cific-area-of-my-object.1237444/#post-7887049

Anyway, the information can be useful for you in the same way, so i recommend you to read the previous answers

Now about the Post effects file, i also know that but i was very dumb and change my own file -.-"

 

Not sure I understand what you mean.
I am also using the Y Up file from intel and Unity does not give me any such errors.
Which version are you using?

I'm using 2021 LTS and 2022.2 Beta

As for the manual method, I have already created many hundreds, if not thousands of assets for all kinds of platforms. PC, Mobile, VR; it really does not make any difference in the vast majority of cases which are simple geometries.

Especially in low poly platforms like mobile. Another reason why it doesn't make too much difference even on larger more complex geometries, is because Unity repackages the UVs anyway to prepare them for baking.

It used to be bad in some older Unity versions, but it has improved quite a bit over the years.

 

This stuff is the stuff that sells Unity. Really great to look at!

 

@pierred_unity can u please tell how to achieve the same result with only APV baking ??! I am struggling with leaking, long baking times and noise..

 

i was using 2021 LTS but i delete that project and i'm working with the other version of the sponza... i tell you what, i'm going to download again that intel sponza file and create again the project and i will show you how it looks here, later.

some years ago i was struggling with light leaks too, i fixed that with more lightmap resolution. maybe that can help

 

I am asking about APV (Adaptive probe volume), the new baking tool which was used in enemies demo and bakes complete indirect lighting data inside probes, its much more suitable for bigger worlds

 

oh sorry i did not read it well, but maybe you should ask on a thread about adaptive probe volume, this is normal basic lightmap thread

 

@pierred_unity well, you get me interested in that technique now, i need to learn how to use them too

 

I guess we should use APV alongside SSGI (Medium or even low works well) to get the best results.

Although could somebody tell me if SSGI is viable on older GPUs like GTX 1050 or 900 series?

 

@Ruchir I've used SSGI and experimented with it and APV many times, with a laptop GTX 1070.
No matter what you do, SSGI will have a noticeable cost. That said, if you use it alongside APV, you can get away with fairly low settings and it'll help a lot with the noise APV doesn't handle.

For example, set quality level to low (or even beyond that, reduce number of rays yourself below 'low' until you find a good amount for yourself) but keep Full Resolution On. It'll give you acceptable performance, and help a lot with APV noise.

Disabling full res can lead to some noticeable flickering and other issues, but it does make a big perf difference.
Although, with APV In particular you can get away with low settings, as long as full res is on. Then again it depends on your project, so try with and without full res.

I don't remember the GPU cost number, been a while. Maybe 2-7ms depending on your settings.
SSGI by itself, without APV, is going to be harder to balance though.

If you intend to use SSGI, you might want to bake everything with APV. Since if you use lightmaps, SSGI will override it, doesn't work with lightmaps. And that lightmap object won't receive any APV lighting information, so it'll be SSGI only.

SSGI In general does better in exteriors. Terrain, vegetation, etc. Interiors are more difficult.
APV helps a lot though.

Honestly I wouldn't mind APV being more expensive for improved quality. Not having to worry about lightmap UVs is really nice, plus, dynamic

It's the way to go for sure. Can handle bigger scenes as well.
Unity's lightmapper was a pain to use for me.

Either way, as pier said, APV is a welcome addition. You can bake a lot of small things with APV, and only big/hero objects as lightmapped.

Reminds me of Bakery's own light probe system, which is seriously amazing. Makes light probes look.. bad

Much better lighting (compared to light probes) and basically automated.

 

although in your image, the pillar seems to be floating ... Does that have to do with the resolution as well?

(low resolution shadow?)

 

APV is almost always producing this dark blobs even on planar surfaces for some reason. Any chances this will be fixed in the future?

 

ah yes that makes sense

 

It would indeed be really helpful.

I currently have purchased bakery but never used it because it had some issue with HDRP in the past, and none of the sample scene worked for me, is it really good now?

 

Honestly it still feels a bit lacking in HDRP and unstable compared to URP/built-in, but so far it works for me after some issues (worst thing is they're random, no clear reason on why it happens.. or how I fixed it)
Make sure you use Optix 7, best denoiser for HDRP with bakery, it can handle the extreme light intensities HDRP uses.
Other denoisers can cause serious issues.

Although I like setting fixed exposure to 0, that way it's the same as URP/Built-in, where directional light is 1-2 intensity.
Depends on your needs/preferences and project since you lose the realistic light intensities/exposure.

Also, be sure to read the documentation, you probably know it but sky light can't be setup as URP/built-in, you have to bake the sky probe (from bakery's baking options) and then drag the texture into bakery's sky light component.

 

Today i had the time to improve my test with everything i've learned with @pierred_unity comments (thank you for your patience and dedication on this post )

I'm really happy with the results by now. But what do you think? after all this is for learning and feedback
(images updated because i forgot to put details in some materials)







There are other images attached with other post effects. I also tried the probe volumes stuffs and is not bad at all, it has its issues but i know is experimental right now, so.

If any of you think i can improve the image with other things i would like to know you ideas.
BTW, i used an online tool (Jimpl) to get the metadata of the reference image and use that for the physical camera in unity, for the ISO, Lens and all that stuffs

 

I don't really use high-quality shadow filtering that often, but I do feel that the denoising algorithm could be a bit better as it seems grainy even for medium sample counts at reasonable blur amounts. (or maybe I'm missing some settings)

I recently was taking a look at Nvidia's denoiser's implementation, they looked really good tbh:


(But I know they must be limited to Nvidia hardware )

EDIT: They support DX11, DX12 and Vulkan

 

Sorry for the long text...
I tried the different AA modes and i tried those settings based on one old video you did for 2019.x but do not forget that i'm working with a 1050 laptop haha and i want to take the best fps number i can get , so i leave at SMAA which is not that bad and does not jitter (like TAA in my case) because i also want to make a video showing the results.
The shadow resolution was at 4096 but at 30-35 fps. so i set the resolution to "ultra" which is 2048 at 40-48 fps. (yeah i know i need a better laptop for what i want)
The other thing i've been seeing is that i wanted to lower the saturation with "color adjusments" but that also lower the effect for the lightmaps i was crying before so i do not know if doing that is a good idea...

20 minutes later...
I think i know the problem with the shadows now, the "scene settings" objects has this "shadows" settings, i think i need to crank those settings, i will work with that later... thanks for showing that @pierred_unity

 

...Is making something weird with the shadows, i even disable the shadow cascades, i also set the "directional light shadows > resolution tier > max resolution to 4096 and set the shadow resolution in the light settings at 4096 too and is still doing this weird thing, when you are facing the object, the shadow looks better, but when that object is near the edge of the screen the shadow looks like dithering or granulated and also the shadow up there is disappearing
click the images below




BTW i edited the previous post because now i'm interested on this problem

 

I managed to fix the graininess on the shadows from the distance light and also the contact shadows. The first one was for the shadow cascades (maybe you can try that @Ruchir )
the second one was the contact shadows samples





But i still have the problem of the contact shadows disappearing when they are close to the edge of the camera

 

Contact shadows are just screen space shadows and therefore lacking offscreen information, so they blend out at the screen border (just like screen space reflections do).

 

I'm using TAA right now and i move the settings to make a balance between quality and not jittering, but is very blurry even when i stop for maybe 2 seconds.

 

We had done a similar learning situation a while ago, not to photo match or reverse engineer camera profiles but just to test more of our lighting workflows.

Building something on the scale of Pierre's Lotus post monthly would be lovely.
(Though having the Amalienborg Palace scene would make for lovely testing grounds )

But we did have the same initial photo in our pure ref file.
I have grabbed a few screens.

Feel free to dig in.

 

I believe this is also the flashy ref scene-style