LUT shader issue

I’m working with 8*8 Lut textures on other platforms such as spark ar or effect house all of may Luts are working good but my first try on deep AR studio v4 mac os the result is very low exposure (so dark ) not the same as other platforms why :weary:??
I tested it on Mac built in camera and on ios app tester

Hi, Abdo, could you send us some examoles of your LUT files and the Studio project so we can see how they are set up in the Studio?

We also use 8x8 LUTs.


this is My Lut texture on ios tester app it looks higher contrast and very low exposure
on other platforms or software it works !!
my phone iphone 11

note : I can not upload the project file here because i am new user

@jelena can you try this LUT please

testLut.deeparproj.zip (1.1 MB)
Uploading: Screen Shot 2022-09-30 at 14.31.33.png…

Here is a test project and screenshot with your LUT. Is this correct or do you have screenshots of how the LUT behaves on other platforms for reference?

@jelena
THIS how the LUT behaves on other platforms
and how the lut looks on deepAR tester app Or webcam
so dark and over saturated and contrast
I tried other LUTs but the same issue found

testLutEffects.zip (778.6 KB)
I think this might be due to importing LUT as color data into the studio. I have made 2 sample effects for you to try out. Is the nonColorLUT.deepar effect the color you were expecting.

If you confirm this is the issue I can share the workaround setup and we can change the expected color space for LUTs

yes non color data ( linear ) is more brighter than Lut as color data
but still over saturation
Are these TWO sample effects using my LUT (riko_0808) ??

Yes both are using your LUT

The issue for me is not in a specific LUT but in the way of applying the lut leading to this results .
as I said before I am working on other platforms (spark AR , lens studio and Effect house) that use GLSL shaders and I know that DeepAR studio use BGFX shders . IS this the Reason?


@jelena
For example some times ago i created this filter for a client with this attached LUT
with this Instagram filter link you can compare the result between sparkAR and DeepAR

I understand, I was trying to compare the results to understand the source of the issue.

Thank you for sharing a reference effect

@jelena
Any update about that issue??!

None yet The effect you’ve sent has other elements as well, our internal examples all seemed correct. Do you have a minimal example with LUT only where this difference would be visible?

i created this only simple lut effect on meta spark ar studio with this attached lut
i really hope that help you fix the shader issue
thanks Mr@jelena

Any update here? I’m having the exact same problem.

fix-lighting-01.deeparproj.zip (446.6 KB)

This is a simple project with a neutral LUT, which dramatically darkens the video when applied at 100% – but a neutral LUT should have NO effect at any percentage!

1 Like

Not yet but thank you for the example project we’ll have a look

You are correct there does seem to be an issue in the shader. This version requires a color data texture, but only works correctly with a non-color LUT texture

LUT-fix.deeparproj.zip (23.1 KB)

I have edited your project with a test fix you can use until we implement a permanent one.

Thank you again for providing a sample project

Thank you for the fixed version – that definitely helps! However, with all the non-neutral LUTs that I’ve cared about – basically, everything but a negative color one – there’s a significant problem in the color rendering – saturation and brightness, I think, but I’m not an expert here by any means.

See this example here, where DeepAR Studio is on the left, and Spark AR Studio output on the right, for the same LUT:

Here is the LUT:

Thanks again!
–randy

Thank you I will have a look at that one as well