Bad HDR Lighting from HDR Map

Hi,

I can't seem to import a custom lat/long HDR map into Unity without it applying awful ambient lighting to my objects. The ambient lighting is completely inconsistent with other programs using the same HDR for image-based lighting.

I get similar blown out light curve values with other HDRs. When I convert them to LDR, of course, they look as they should.

What are the correct settings and use case for HDR and EXR files in unity 5.3? What am I missing?

 

I am testing with a new project in 5.3... can you screen shot your texture import settings on that hdr?

 

I think something is iffy here...

Can you try adding a light probe group that encloses that sphere? Does that make the lighting very flat?

 

My test worked fine. If you zip your project, I can verify it.

 

Something is wrong.

Both look wrong to me. One is way too contrasty and the other is very flat. And they should look almost identical. The difference is one has lightprobes and the other doesn't (but it should be lit by the global ambient source, which is the skybox, which should result in the same lighting)

 

(I over-exposed the cubemap because it exaggerates the problems)

Light probes look too flat for me (I would expect the left side to be somewhat darker, like the static example looks).

And Ambient just plainly looks wrong. At the very least, that one's a bug for sure.

It's case : 751864

 

Thanks for verifying and posting the bug guys!

Here is my project packaged up:

http://www.qt-ent.com/WIP/IBLIssue.unitypackage

 

Thanks for the file. I can reproduce your saturated banding effect just by opening it.

 

The best results were to change RGBM encoding to off.
But, this still leaves us with that dark spot on bottom. I tried my HDR (a sun-lit parking garage) and it doesn't have such a dark spot. By the looks of your EXR in an image viewer, I don't see why it would be black underneath.

My next question is: do you have other EXRs that do this?
I tried converting to HDR and, as expected, produced no dramatic change.

 

The exr I gave it does it as well.

Also, yeah rgbm off improves it, but isn't that effectively turning hight dynamic range off?

 

Good question AcidArrow.. Docs are ambiguous. I wonder if turning encoding off leaves the data as is, which is true HDR.

Can you post your HDR here, AcidArrow?

I think this is a very important topic that requires clarity.

 

It's this one : http://hdrmaps.com/small-apartment

I don't see why it would be related to the exr file.

 

I have EXRs and HDRs. They all produce this bogus result.

 

It doesn't do it with my HDR files. And, I have LOTS of them. Unless this is something you noticed with 5.3.. I just started using it today.

 

Try a repro with these:

http://www.hdrlabs.com/sibl/archive.html

Each one also includes an LDR version. Make sure you use the HDRs.

 

This one's just plain wrong.

And light probes produce way too even lighting for the way this exr is set up.

I don't think the files have anything to do with it. This is a bug. I filed a bug report, I think we should just wait for now.

 

Thanks AcidArrow. Can you drop a link to the bug report (if one exists)?

 

I did tick "public" when reporting, but I don't see anything on the issue tracker. (maybe it takes a while for it to appear there? the latest issue I see there is from yesterday, and I find it hard to believe no one else posted a bug report today )

I'll post here when I have any updates.

 

Thanks for submitting that, AcidArrow.

QT: I just tried Arches_E_PineTree_3k.hdr from the link you sent. Looks fine. What does it look like for you? What I mean is: I don't see dark spots. This is just the ambient from the skybox on a Standard Specular shader.

 

How does it look if you add light probes to the scene?

(or if you over-expose the cubemap in the material?)

 

AcidArrow: light probe shot attached below. Looks as expected.


Overexposure matched the environment as expected also. It did not behave like the other EXR file, which had a dark spot where it was not expected.

 

Why does it look as expected? Isn't it supposed to capture the lighting of the environment? Which in an empty scene is practically the same thing that ambient does?

Also in your first image, I am pretty sure the sky color (on the sphere) is wrong. It looks much darker and way too saturated.

And the light probe image is way too evenly lit.

In short, your examples exhibit the same issues.

 

AcidArrow, are your observations something which occur only in 5.3?

 

Why?

(I believe so yes, but I don't explicitly remember testing this on other 5.x versions, so I could be wrong)

 

I wonder if you think this is an old problem.

QT: I assume this is a new problem, with regards to your original post? Or, have you had trouble with EXR files in earlier versions?

 

I've never had luck with HDRs in Unity 5, but I've never dug deep into why it is until now. Their tonemappers haven't been good so I never really went far with it until 5.3 came along with their new one.

 

(slightly off topic, does anyone knows what exactly happens when you tick "public" in a bug report? I was expecting the issue to show up on the issue tracker, but it's still not there)

 

AcidArrow, that is great news. Thanks. As long as they 'are on it'...

Now, I wonder if this is a new issue or not..

 

Considering the amount of people that reported on the forums that their ambient lighting started looking weird in 5.3, I'd say it's a new issue.

 

Great job, folks!

 

Very exciting. Thank you for such a complete response to the problem.

 

Guys this is still occuring in 5.3.1f1. I guess it hasn't been patched in?

 

I believe it was fixed in p1, not f1.

 

We are using 5.3.6p4 and still experiencing this issue.

We have been testing on iOS, android, and linux servers. our scenes use .hdr for ambient lighting, and they look decent on all the platforms, except iOS, the most important one in our case.

The more colorful the skybox, the darker and more distorted our colors appear, as if being multiplied.

Our short term fix is keeping the exposures low and saving the images out as .jpg, without exposure data, and using very low values of ambient lighting for the scene.

when we do this, we lose a lot of the nice color influence that the skybox provided, and often have to add additional dynamic lights to boost the scene.

Any help is much appreciated.