Antialiasing Issue for progressive vs bucket

[wessam]

Hi,
on GPU RTX
when I compare progressive vs bucket renders it is visible that the edges are not correct for the progressive method, and it is more visible when I render selected objects and try to compose the render over and existing image, this was happening for years on different workstations and I finally decided to ask
please advice.

[Muhammed_Hamed]

Hey Wessam,

Progressive is the recommended way to use V-Ray GPU, on a simple scene I cannot reproduce the antialising issue you mentioned
Do you have a screenshot or scene? we need to reproduce this on our end

Best,
Muhammed

[Joelaff]

I wonder if the OP is referring to the rough edges often seen (esp with progressive) on renders with Render Mask set. ??

[wessam]

I wonder if the OP is referring to the rough edges often seen (esp with progressive) on renders with Render Mask set. ??

yes, exactly

[Joelaff]

Not sure if there is a way to avoid. I usually don't use progressive. In fact, I hardly use progressive for anything.

It does put a warning in the log (with some interesting spelling):

 Warning : Render subsets and progressive sampling lead to artefacts along object edges.

[Joelaff]

You can make a matte in post (from a previous render's alpha perhaps) and expand the matte to render more than you need, then shrink and feather it when you composite. That is what I have done when I needed to render individual objects. But normally we just end up re-rendering the entire frame.

[fixeighted]

Not sure if there is a way to avoid. I usually don't use progressive. In fact, I hardly use progressive for anything.

It does put a warning in the log (with some interesting spelling):

 Warning : Render subsets and progressive sampling lead to artefacts along object edges.

Did you mean in the spelling of 'artefacts' ?

That's totally fine, as it's just the UK version.

It's the 'lead' that is incorrect, as it should be 'leads'.

Just saying

[Joelaff]

Chiefly British I did not recognize that was one of the British Flavours.

Given the subject is plural I would say “lead” is correct, rather than “leads.”

EDIT: But I suppose the meaning implies, "Render subsets with progressive sampling leads to artefacts along object edges," which would indeed be singular, and make "leads" correct, as well as be more clear.

EDIT REDUX: What the heck am I talking about? “Subsets” is still plural either way. So “lead” it is. Carry on.

[wessam]

You can make a matte in post (from a previous render's alpha perhaps) and expand the matte to render more than you need, then shrink and feather it when you composite. That is what I have done when I needed to render individual objects. But normally we just end up re-rendering the entire frame.

Thanks, though that’s a work around bur still not perfect, specially with high resolution renders and super picky clients

[wessam]

Hey Wessam,

Progressive is the recommended way to use V-Ray GPU, on a simple scene I cannot reproduce the antialising issue you mentioned
Do you have a screenshot or scene? we need to reproduce this on our end

Best,
Muhammed

Thanks, tbh it’s amazing how it is in the log like the previous post, and you guys are not able to reproduce. The issue been there for years, I want to help you with the investigation but I am on a tight deadline currently.

[fixeighted]

Chiefly British I did not recognize that was one of the British Flavours.

Given the subject is plural I would say “lead” is correct, rather than “leads.”

EDIT: But I suppose the meaning implies, "Render subsets with progressive sampling leads to artefacts along object edges," which would indeed be singular, and make "leads" correct, as well as be more clear.

EDIT REDUX: What the heck am I talking about? “Subsets” is still plural either way. So “lead” it is. Carry on.

I thought that 'render subsets' was the parameter/option label, so singular, but apparently not.

Given the statement implies that the two things, used together, produce artefacts, then leads is still correct I think, instictively (I'll check with my tame linguist later), but a simple
solution would be to use 'will lead to' or a variation thereof

I do love a bit of pedantry in the morning

Sorry OP...didn't mean to hijack

[wessam]

@Muhammed_Hamed
please check the screenshots attached,
Again the issue is worst when making a masked render, (like render selected)

[wessam]

Hi,
this remains a significant issue that needs to be fixed guys! it is amazing to be aware of an issue and it can easily be reproduced.

at the same time throughout your ecosystem, you always recommend progressive render like for cloud render, and yes, it is better and faster than bucket in most cases if not all.

[wessam]

a sample scene to check that reproduce the issue
https://drive.google.com/drive/folde...U_?usp=sharing

[Muhammed_Hamed]

We will see what could be done about this ASAP
For now we have been busy with V-Ray 7, I will get back to you shortly

Best,
Muhammed