Jagged lines in Arnold high res render

[Anonymous]

Hi, I wonder if anyone can help?

I am learning Arnold and 3DS max. When I rendered this image in low res I didn't get any jagged lines but now I am rendering in High res I am getting these jagged lines on some of the objects like this chrome pole.

Does anyone know why this would happen?

I don't think it can be samples as I have these super high! - Camera - 10 Diffuse - 7 Spec - 7 Transmission - 6 (is it possible to have samples too high? I am still trying to work out the magic number for a high res image with this scene)

Samples on lights are 5.

Any help would be really appreciated.

Thanks so much. 

Hannah

[ryaanj]

I'm posting to keep this alive.  I'm having the same issue, just wondering if anyone else has seen this, or if you ever got it resolved.  Using AOV's I've verified it's in the specular direct and indirect.  You really see it stand out on the specular highlights.

If I increase the Sample (Pixel) Filter width the highlight gets thicker (correspondingly) but still has jagged edges, until I get to ridiculously large values.  It seems that this should blur the highlight, not make it thicker but still jagged.  This is very frustrating.  The jagged edges are way larger than the pixels in the image.  It looks to me like it's the same thing in the sample image @Anonymous posted.  Any ideas out there?  Images attached from my scene.

[madsd]

I am not able to reproduce with either cpu or gpu without having to significantly lowering AA, on a test model here.

Any chance you can attach that can top so we can inspect it? ( including the light map, I dont need anything else )

[ryaanj]

Archive of the scene I've been testing with attached.

[madsd]

Just had a quick look.

You use very small lights with a very high intensity, so the highlights sits a good portion above 1.0 ( pure white ) that results in aliasing of the highlights.
So and I can remove this aliasing by bringing the highs down.

I am able to fiddle a bit with intensity and get sharp reflective edges with no overcranked values.
So it is a matter of adjusting the highlights while still maintaining the overall look.

There is no safeguard against overcranked values for highlights, so you can go way overboard and make everything look very jagged easily if you push it too much.
I see you set indirect clamp to 5 from default 10. You can have a go at the direct and adjust that as well to make sure you are just touching the border.

[madsd]

Had one more go in between bbq is getting ready for ox beef ^^



And a screencast video. Note I use the GPU for faster result on my machine.
Fractionally broader lamps gives some nice edges without completly destroying everything.

[ryaanj]

Wow, playing with 3ds Max during bbq?!  That's dedication @madsd .  

Thanks for the tip on the lights!!  I'm coming from Mental Ray so I'm used to lights having physical units and those huge values would be normal.  I cranked my lighting waaaayyy down and switched to Physical Camera Exposure Control.  I also increased the size of the lights and moved them around a bit.  I think the lighting is way more balanced now.  

However, still was getting lots of aliasing.  My renders do not match your results.  (side note:  I cannot get the GPU to render activeshade.  I also cannot get the denoiser from the denoise tab to work at all.  As soon as I switch it on, it just doesn't render anything.  I'd really like to get that working because there are hundreds of images/labels to render and cranking the indirect specular samples up is obviously very expensive.  I downloaded a sample scene you uploaded on this forum post and it won't render either..  I may have to look into the graphics card or driver or something.)

Even after adjusting the lighting and setting the clamping back to default values, I'm still getting aliasing.  I think I have traced it to the roughness, or rather the lack of roughness.  I did a lot more playing around and loaded some other materials to compare.  Here was my current result from just adjusting lighting and stuff:

Pretty good, but definitely still has some jagginess.

I tested a satin metal that had a bit higher roughness and it actually looked better.  So I decided to play with that for a while.  See the image here, roughness at zero:

Super jaggy-looking.  I cranked the roughness up to match my satin material:

Better!  I added some anistropy:

Then rotated the angle of the anistropy:

This still needs some work, but I'm feeling pretty ok with these results.  The lighting was a big help, defo.  So thanks for that.  However, on my end it appears that the jagginess is coming from the specular highlights if the material is completely un-rough.  I still don't know why that would be the case, but I can work with cranking the roughness up I think.  

I do have some glass and plastic materials that are very glossy and will be another story, hoping I don't run into this again there.  I have worked with Autodesk on other issues with those models for quite a while.

Thanks for the input and the weekend time!  One of these days I hope I'll get Arnold figured out like I did that other renderer..

[madsd]

Looks HOT 🙂

Better for sure.

Yes, it's when those very high values lies close to darker areas, black and so on with no filterting, so as you now know there are different ways to get that smoothing going, good job so far.

For the GPU and OptiX denoiser, you would need a GFX card from NVIDIA!