HDRP - Batching does not work

Hello, trying to get batching to work with no results

Have a simple scene with single prefab (mesh + material) being rendered with HDRP Lit material. Material is set to use GPU Instancing. Number of batches: 6

Each time I duplicate prefab, number of batches goes up, and up, and up - by 6 each time.

Material has one diffuse map and one emission map.

No scripts, no custom shader, all standard stuff (apart from mesh and textures).

Unity v. 2019.1.7f1, HDRP v. 5.16.1

What am doing wrong?

Screenshots:

Two prefabs are there (one duplicated off another), second one is disabled:


After enabling rendering for second one:


Prefab setup:

 

Bump - anyone? It seems that GPU instancing is not working here. I red through manual and tutorials on batching topic and everything is set up as it should be but still no result.

No particular information can be found also in profiler or frame debugger.

GPU Instancing works however in standard Unity rendering pipeline.

What's happening?

 

Also happening for me.

 

OK, after more testing (because I have nothing more interesting to do than investigating what's wrong: Unity rendering or Unity documentation....) it seems that docs are not updated.

Batching works, but:

- when material is checked to use GPU Instancing and SRP Batcher is enabled there's no "draw instanced" calls in the frame debugger visible and Stats display batched calls with - sign

- when material is checked to use GPU Instancing and SRP Batch is disabled, you can observe "draw instanced" calls in the frame debugger and Stats displays batched calls properly, as documented in the manual

Anyone from Unity Dev team please comment on this - is my understanding is correct?

 

Use the SRP Batcher? https://docs.unity3d.com/Manual/SRPBatcher.html

 

Hi,

I use the HDRP Lit shader and enabled GPU instancing for objects copied and scaled - rotated around, but the batches are still enormous (like 3000) and "saved by batching' metric reports a minus -2000, is this meaning the batching is working ?

 

Does the documentation need to be updated ? I don't see an advanced options in the HDRP asset.

 

In March 2020 I have no idea- that whole thing with SRP transitioning is a one huge mess, on unity side.

Maybe some big customers with dedicated support from unity have any understanding of how to properly and efficiently use new rendering pipeline.

Little guys like myself are left with nonexistent or outdated documentation, confusing blog posts and sponsor videos, completely unhelpful forum and bug report replies. It's hit and miss game.

Great that there's raytracing tech you can show off, but not being able to properly investigate performance, without using some loose scripts, posted somewhere on the forums (because I have too much free time I can spend on hacking around instead of developing my game...) its just pathetic. And this is just a tip of the iceberg of missing or broken things in the new pipeline.

I should have stayed with built in renderer. It's at least two years, if not more, before srp become ready to production use. I wish somebody would mentioned that in multiple blog posts and videos they advertised srp in.

 

Also still waiting on figuring out whether my batching works or not. It says 48 batches and -48 saved. Does that mean that I have successfully messed up every single instancing-attempt I have done, or does it mean that it works?

I'm sorry, but I have to agree. It's impossible to do any real work here, without creating all the building blocks to fit into Unity to make it work. How is there not a single particle-shader for HDRP yet? Yes, I've tried the beta-package they made, but those don't support colors, so you have to write those yourself. That's such a weird choice to me.

 

I am using Unity 2019.37f1, HDRP.

I still have this problem about batching, I have a lot of objects with the exact same material and texture on them, the are not marked as static batch since they are moving, and the material is mark to GPU Instance batch. Guess what? I get exactly the same result that you guys: A high number in "Batches" and a negative number as high in "Saved by batching".

I don't find any place in Settings or HDRP asset to turn on/off SRP batching neither!

Could someone from Unity shine a real light here? Please

Regards,
Carlos

 

+1 to this. In frame debugger it shows that SRP Batcher works and batches things, however, if you try and use RenderDoc, you'll see that in fact absolutely nothing gets batched, even static stuff. Unity 2020.1b8, HDRP 8.1.0





Making the boxes non static and enabling GPU instancing on their material does nothing as well. Theres still one drawcall per box.

cc @arnaud-carre

 

Look in detail on the draw call and the definition of SRP batching you'll see the difference .It indeed does 1 draw call each but reduced the states changes from 5-10 to 1. That's what SRP batcher does, reducing CPU overhead by reducing the state changes that occurs when you change the shader.



Without SRP


With SRP



Still 2 draw calls, but overhead for each is significantly reduced.

regards

JP

 

Can someone please provide me with how to use batching properly in HDRP I have looked at all the documentation and it's either all outdated or very difficult to follow. Static batching no longer works in HDRP and GPU instancing seems to be causing trouble with certain people.

I have an RTX 3070 and I am getting 500 batches on simple scenes and 20K batches on larger but medium sized scenes I cannot release a game like this if profiling it is broken as the fps count is very low.
I was told about the SRP batcher but I can't find it in HDRP and the docs don't help or are telling me to use scripts and such and such. I thought HDRP was production ready?

 

After working with both pipelines for long time now, I think SRPs are nowhere even close to near production ready, URP not even has point light shadows and both URP and even more HDRP are generally extremely slow comparing to standard, both pipelines are largely useless imo for any serious project atm, i give it 1-2 years to be fully realized, if ever can be with such complexity and overhead.

 

That's a real shame because I was just getting to like HDRP. I can't go back however because of things like Subsurface Scattering and the beauty of the shaders. A lot of what you say is right and particle effects aren't working in HDRP properly and other stuff but there hasn't been anything serious until the batching issue.

Though I still didn't get an answer to my question about how to use the batching?
I will have to bring out mesh combine studio if the batching is really that bad because it uses its own batching system and works on all pipelines.
If all else fails I'll have to go back to standard but we'll see I've come to far to turn back now.

 

If you want/need to use it - then use it. Sure, its not an ideal solution, but its really good nevertheless. We use it for our project btw:

They do, you just need to use HDRP compliant particle shaders.

Static batching still works, i dont know where you got the information that it does not. SRP Batcher is enabled by default in HDRP and can only be disabled through scripting. Anyways, batches is just one of performance metrics, open up GPU profiler and look at what exactly is taking the most time. And if you think something takes more than it should - file a bug report.

 

I find only one easy way to force HDRP to use instancing - import hybrid rendering package to project, and throw all static geometry in to the entity world.

 

You are probably right it's probably a bug because if the Batcher it's enabled by default then it means Unity just can't handle so many objects and they need to be combined..

In regards to the particles it looks like they are listed in the package manager instead of out of the box.

Congratulations on getting onto the PS5!

 

Ah I just looked up the Hybrid Renderer and I understand now. Thanks for that at first I didn't understand what you meant by Hybrid Renderer I was thinking is this a new renderer that combines HDRP and URP but nope it's just some troll at Unity who should get a pay cut for naming it something other than DOTS.

 

Update My results agreed with what @arnaud-carre said
However I could not disable it in HDRP in the asset it's not there only via the script I did it.

My results agree with what the above Unity Personnel said.
So I got the SRP Batcher Profiler script and put it on my camera and found out that GPU instancing is disabled while SRP Batcher is enabled and only one will be enabled at a time. It's important to know that HDRP does not support regular static batching so only SRP batching or GPU instancing are options here.
So the problem is it gets weird:

Scene1:
In my scene with 3000 standard with a new HDRP standard material applied to the cubes the SRP Batcher performs at 120fps while disabling SRP the GUP instancing starts working giving me 130 fps basically saving 1 MS which is good and it shows 2700 saved by batching which is huge.

Scene2:
However in another scene with an asset pack i bought with similar props and only color in the material the srp batcher
performs the best 55fps in the 26000 batches while disabling it and putting GPU instancing on I get only 3000 batches and saving 23000 batches but the performance is even worse now with only 47fps. That doesn't make any sense.
By having GPU instancing off completely and SRP off completely I get 52 fps.
I can't figure this out because GPU instancing is meant to support a very high number of objects where here the GPU instancing fails hard over having it disabled....

Scene3:
Running this in another scene that is more complex with many buildings and materials shows that the SRP
batcher really is the better option with it being turned on saving 80% of the set pass calls.
Again the GPU instancing performs garbage here with a good 20fps worse than the SRP batcher despite saving many 80% of the batches in this 16000 batch scene.

So Basically having the SRP batcher enabled which is the default behavior most of the time gives the best results but other people have said that the GPU instancer is very finicky and unreliable and after seeing what I saw I do agree.

However my video card is one of the best out there and other people have reported similar fps that I have when it comes to drawing such dense levels so my only assumption here is that maybe to get more performance I will have to look elsewhere past the materials and likely into the shadows, occlusion culling, backface culling or probably the most effective one-mesh combining.

I am pretty sure that if I was to combine those 2 thousand cubes into 1 mesh I would get the most performance here at the cost of disabling culling.

FINAL UPDATE: I combined the meshes of the Scene1 using a free tool on the asset store and yes the performance gain is enormous giving me about 100+fps.
https://assetstore.unity.com/packages/tools/modeling/mesh-combiner-157192
Now I feel kind of silly looking at Scene 2 and realizing the modular castle is not combined
and looking at scene 3 however I need something different because mesh combining will output 1 material so unless the houses will all be atlassed it won't work that is why Mesh Combine studios grid system will work for that.

 

You also can manually batch your objects with BatchRendererGroup API

 

@arnaud-carre OK, so one question about "Stats" window and SRP Batcher. As I can see here - "stats" still does not properly display the batching metric:



In the frame debugger I see that for drawing opaque objects I have these 4 SRP batches. Regardles of the performance discussion above I'd like to know how this compares to 357 batches that you can see in the stats window, to the right?

Because SRP batcher does not actually limits number of draw calls, is this the reason why I am seeing those 357 batches in the "stats" window?

If it's correct way of understanding, what's the benefit of the SRP Batcher then? Whenever you read or listen about graphics pipeline optimization there's this mantra being repeated all over everywhere - bring down drawcalls. If this is not how SRP Batcher works, as you mentioned above it's also bypassing instancing path - what's the purpose of it?

Last question - what would be the best approach to render hundreds of objects with the same material (shader) but different parameters (i.e. color) in URP?

Following up your response to SilverStorm - then using SRP Batcher in URP and hunderds of objects (before moving to ECS/DOTS) should I use renderer copy of the material, not the "sharedmaterial", let's say referenced in the Start, to change individual parameters of that copy of the object (i.e. change it's color)?

Sorry for the long post but maybe, if answered it could bring all those questions / discussions / answers related to the SRP batcher / instancing in one place so peoples can learn from it little bit better way than just going through multiple blog posts and vidoes, all of those touching subject but none of those actually providing a comprehensive look at the subject.

Thanks!
S.