[gotoxy av-media]

i thought by posting those issues it would be helpful for NL to improve their render-engine!

i have found some more issues, which i would like to post in this forum...but i won`t, due to a lack of response...

regards

[dariolanza]

Hello renbry,

I'm not sure if the Material ID (being a material identifies) should present antialiasing.
I'll let you know what do we come with.

Greetings

Dario Lanza

[tom]

i thought by posting those issues it would be helpful for NL to improve their render-engine!

Could you please render the same scene with an improved engine and post the results to see what kind of improvement we need here?

i have found some more issues, which i would like to post in this forum...but i won`t, due to a lack of response...

Of course, you're free to do that. It's already our part to improve it and not your obligation.

[zdeno]

....

i have found some more issues, which i would like to post in this forum...but i won`t, due to a lack of response...

regards

DECOY !

nice try ! respect !

[Bubbaloo]

Wouldn't antialiasing at material ID edges create hue shifts that would defeat the purpose of a material ID in the first place?

[gotoxy av-media]

first of all thank you for the feedback!

@Dario Lanza

What is the reason for NOT having the same AA as the alpha-channel?

@tom

There is no need to render with other engines, this is no competition!
It`s all about maxwellrender and how to get the best results by understanding how things work.
Take a look at the top of page 1 and here are my questions:

...would you please tell me what i did wrong?
...how to get useful mat/obj-id that doesn`t differ in AA in comparison to the Alpha-channel?!
...or what is the intention of these channels? ...and how to use them correctly?

@bubbaloo

what is the purpose of mat/obj-id?

[bograt]

Vray had the same issues, as frustrating as it is material ID has never been great for making masks.
I think Bubbaloo highlighted what may be the problem; AA would surely blend the different hues rather than the luminosity.. maybe its time someone developed a 'multi-alpha'

[Bubbaloo]

@bubbaloo

what is the purpose of mat/obj-id?

I use it for subtle hue shifts/corrections post render.

I think if you are looking for individual masks, you should isolate objects and make alpha masks.

[gotoxy av-media]

@bubbaloo

yes, i use it for modifications in post, too!
It is limited for very thin lines...(AA)

and

yes, i had to render several alpha-passes for the different objects, which is very time/energy-consuming when you need an animation sequence!

...

@bograt

multi-alpha sounds nice!
just like the shadow-pass, which saves separate files for each light, but for mxms (mat-id) and for objects (obj-id)

[tom]

Unlike Alpha Channel, Id Channels are not receiving the same implementation of pixel subsampling driven by the sharpness parameter. So, currently the antialiasing coming from Id Channels cannot perfectly match Alpha Channel. Naturally the difference is more evident in thin lines where antialiasing is heavily visible. In other words, Id Channels are not tied to Sharpness. Maybe I can make a suggestion if you tell more about your scene, aim and workflow. Rendering a grid of thin mesh and complaining about "Id coverage of this object is not matching with alpha coverage ruins my work." sounds senseless.

[eric nixon]

Hmmm, I havent read the whole thread but I would like to add something constructive on the general subject.

- Use matt id, not object id, because it renders clean by sl6, theres no reason to render higher as far as I can tell.
- Render matt id's for stills after the main render, because its better to concentrate on the main render when we press 'render'.
- Use pure R,G,B for matt id's to avoid colour bleed between id's, so its generating 3 id's per render, (theyre very quick renders - sl6). So therefore its neccesary to set off extra renders to get extra masks, I usually need 2 matt id passes.
- Use Photoshop with gausian blur 0.3...!

And then they look like this;



The shift lens is making the thin lines vertical ofcourse which helps.... In some 'wireframe' situations an extra alpha pass would be needed as has been mentioned.

Hope this info helps someone... Just wondering why object ID renders slowly, does that have full AA? is it less slow if rendered with the main render? probably...

[gotoxy av-media]

Unlike Alpha Channel, Id Channels are not receiving the same implementation of pixel subsampling driven by the sharpness parameter. So, currently the antialiasing coming from Id Channels cannot perfectly match Alpha Channel. Naturally the difference is more evident in thin lines where antialiasing is heavily visible. In other words, Id Channels are not tied to Sharpness.

well summarized!
so, if i don`t touch the sharpness parameter (which i did!) - i would expect the same AA in Alpha and ID channels...

Rendering a grid of thin mesh and complaining about "Id coverage of this object is not matching with alpha coverage ruins my work." sounds senseless.

hmm, i don`t know what you are talking about?!

Hmmm, I havent read the whole thread but I would like to add something constructive on the general subject.

thank you!

[renbry]

Thanks for the explaination Tom,

I might have problem in the misunderstanding that a pixel (think a bucket of information) shouldn't have pixel-filter-matched sub channels (AOVs) There might only be a few exceptions to not having pixel-filter-matched sub channels such as integer-based AOVs for diagnostic purposes (cpuID for a distributed bucket renderer)

I would always expect to have 'samples aligned' whenever i'd like to have an R,G,B or visibility A, or materialID, or objectID etc etc. Those values must sit in the same 'bucket' and be sample aligned; whether i'm rendering a wire grid or not...

Vray has AOV controls for 'filtering enabled' which lets the user not filter the pass in the case of z-depth or velocity.

Please make sure the samples are filtered and aligned from the beauty, through the AOVs otherwise they're fundamentally useless.

[tom]

Matt, you're absolutely right and we're going to improve it.

[gotoxy av-media]

aha!