Author Topic: Corona Bump is so broken  (Read 7955 times)

2022-12-10, 21:10:35

Basshunter

  • Active Users
  • **
  • Posts: 279
    • View Profile
« Last Edit: 2022-12-11, 16:29:53 by Basshunter »

2022-12-10, 22:23:36
Reply #1

dj_buckley

  • Active Users
  • **
  • Posts: 872
    • View Profile
Is this behaviour the same when your texture is plugged into a Corona Bump Converter?  Not infront of 3DS Max to test it

2022-12-11, 16:29:26
Reply #2

Basshunter

  • Active Users
  • **
  • Posts: 279
    • View Profile
Is this behaviour the same when your texture is plugged into a Corona Bump Converter?  Not infront of 3DS Max to test it
The result is worse. For some reason, even lowering the filtering of the noise node (as it is suggested in the video) gives you a bad result when using bump Converter node.
« Last Edit: 2022-12-11, 17:53:11 by Basshunter »

2022-12-11, 17:48:27
Reply #3

aaouviz

  • Active Users
  • **
  • Posts: 882
    • View Profile
    • Another Angle 3D
Actually very interesting...
Nicolas Pratt
Another Angle 3D
https://www.instagram.com/anotherangle3d/

2022-12-11, 20:13:19
Reply #4

lupaz

  • Active Users
  • **
  • Posts: 951
    • View Profile
This always annoyed me about Corona.
Following...

2022-12-12, 01:08:31
Reply #5

dj_buckley

  • Active Users
  • **
  • Posts: 872
    • View Profile
Probably explains why my floors always look nice when I'm testing using 2d pan and zoom, nice matt look with visible grain, then when I zoom out to render, they look flat and shiny.  Then I end up tweaking the shader so it looks right at normal resolution.

So in effect, we get it looking realistic, then we have to break the shader and make it unrealistic, just to make it look realistic again.  Make it make sense .  Sigh.

Be a good time for the devs to jump in.  I'd hate to think all these speed increases we've been getting over the years are all at the sacrifice of something else.

2022-12-12, 01:29:16
Reply #6

Basshunter

  • Active Users
  • **
  • Posts: 279
    • View Profile
Probably explains why my floors always look nice when I'm testing using 2d pan and zoom, nice matt look with visible grain, then when I zoom out to render, they look flat and shiny.  Then I end up tweaking the shader so it looks right at normal resolution.

So in effect, we get it looking realistic, then we have to break the shader and make it unrealistic, just to make it look realistic again.  Make it make sense .  Sigh.

Be a good time for the devs to jump in.  I'd hate to think all these speed increases we've been getting over the years are all at the sacrifice of something else.
I completely feel you.

Hard to believe the devs didn't know this was happening from the beginning. It's so disappointing.

2022-12-12, 02:20:55
Reply #7

lupaz

  • Active Users
  • **
  • Posts: 951
    • View Profile
Probably explains why my floors always look nice when I'm testing using 2d pan and zoom, nice matt look with visible grain, then when I zoom out to render, they look flat and shiny.  Then I end up tweaking the shader so it looks right at normal resolution.

So in effect, we get it looking realistic, then we have to break the shader and make it unrealistic, just to make it look realistic again.  Make it make sense .  Sigh.

Be a good time for the devs to jump in.  I'd hate to think all these speed increases we've been getting over the years are all at the sacrifice of something else.
I completely feel you.

Hard to believe the devs didn't know this was happening from the beginning. It's so disappointing.

There are many threads about this. Micro detail was discussed several times. I've never seen a good explanation from devs why this is so hard to do in corona.

2022-12-12, 02:42:44
Reply #8

Basshunter

  • Active Users
  • **
  • Posts: 279
    • View Profile
Yeah, I can see there's been couple of threads mentioning this problem in the past.



I Always knew something was wrong with my materials when looked from a distance but wasn't sure what is was until now. Man, you just get a completely different material when you zoom out! The only way to get a proper bump that still works in the distance is to set Blur to the lowest value possible. However, doing this would increase render time.

This is a big deal in my opinion! How is it that one of the best render engines for archviz can't just handle bump properly?!




« Last Edit: 2022-12-12, 02:55:26 by Basshunter »

2022-12-12, 10:19:22
Reply #9

dj_buckley

  • Active Users
  • **
  • Posts: 872
    • View Profile
Turns out I investigated this in 2019 - 3 whole years since I've been tweaking materials to combat this issue - https://forum.corona-renderer.com/index.php?topic=23230.0

2022-12-12, 13:00:41
Reply #10

maru

  • Corona Team
  • Active Users
  • ****
  • Posts: 12711
  • Marcin
    • View Profile
Hi all, first of all, I would really appreciate changing the thread title. "So broken" is not really true.

The current behavior of bump/normal map filtering is expected in Corona. We do however have some user reports where it is clearly not optimal, so we will do our best to improve it in future versions. On the other hand, we are not getting many reports like this, so it can't be that bad. ;) 

There are some reasons for bump filtering, for example imagine that you have an object with strong, sharp bump far away from the camera and you animate it (either the object or the camera). You would like to see smooth movement, but with low or no filtering you will see strong high-frequency flickering of the bump map. Filtering "blurs" the texture so the result will be more acceptable.

You can negate that kind of high-frequency flickering, for example with output clamping (which AFAIK - I may be wrong - happens in fstorm by default), but we do not want it as we always choose rendering quality over heavy bias.

There are also some other fixes/improvements possible to implement in Corona, but they will require a lot of research and development from us.

If you have some examples where the current behavior fails, please send them over - we are always happy to investigate, offer some workarounds, and log specific cases for our devs to review.
Marcin Miodek | chaos-corona.com
3D Support Team Lead - Corona | contact us

2022-12-12, 13:57:14
Reply #11

Juraj

  • Active Users
  • **
  • Posts: 4743
    • View Profile
    • studio website
Yeah microdetail is always problematic. Reduce filtering in either map (native or Corona, or bumpconverter node) and you get possible artifacts. Don't, and your detail is very much angle and resolution dependent. I don't like any filtering (I don't do animations though) but Bump/Normal can stop functioning without filtering. I've also been interested in Vray's elliptical filtering mode.

A solution that worked for me is to render quite high-res. You don't need to multiply your render-time in order to do so, down-sampling of noisier high-res files to lower resolution clears some of that noise. Also, denoised high-res file for most part looks better then undenoised lower-res file.

Possible solution for accurate detail vs animation smoothness is to use Devel/Debug menu override between these modes. There is no filtering option which can be default for stills.

I also don't use native max noise in bump, or much at all. I rather triplanar noise bitmap for more consistent result across resolution. The F-Storm is using its own noise map for good reason.
« Last Edit: 2022-12-12, 14:01:32 by Juraj »
Please follow my new Instagram for latest projects, tips&tricks, short video tutorials and free models
Behance  Probably best updated portfolio of my work
lysfaere.com Please check the new stuff!

2022-12-12, 15:10:41
Reply #12

lupaz

  • Active Users
  • **
  • Posts: 951
    • View Profile
Before Fstorm's example of the pot with real (not from texture or fake anisotropy) brushed metal I'd have never expected rays coming from a camera trying to find light would catch up such small detail.
Fstorm got a better implementation first and it would be great to have it in Corona too.
EDIT: IMO it should be a per-object solution so render times don't increase much.
This example is here.




« Last Edit: 2022-12-12, 15:14:36 by lupaz »

2022-12-12, 15:20:18
Reply #13

dj_buckley

  • Active Users
  • **
  • Posts: 872
    • View Profile
Hi all, first of all, I would really appreciate changing the thread title. "So broken" is not really true.

The current behavior of bump/normal map filtering is expected in Corona. We do however have some user reports where it is clearly not optimal, so we will do our best to improve it in future versions. On the other hand, we are not getting many reports like this, so it can't be that bad. ;) 

There are some reasons for bump filtering, for example imagine that you have an object with strong, sharp bump far away from the camera and you animate it (either the object or the camera). You would like to see smooth movement, but with low or no filtering you will see strong high-frequency flickering of the bump map. Filtering "blurs" the texture so the result will be more acceptable.

You can negate that kind of high-frequency flickering, for example with output clamping (which AFAIK - I may be wrong - happens in fstorm by default), but we do not want it as we always choose rendering quality over heavy bias.

There are also some other fixes/improvements possible to implement in Corona, but they will require a lot of research and development from us.

If you have some examples where the current behavior fails, please send them over - we are always happy to investigate, offer some workarounds, and log specific cases for our devs to review.

With regards specific examples, it should be pretty clear from the initial video.  But when I'm walking around my house, my matt black metal cabinet looks like matt black metal regardless of whether I'm stood next to it or looking at it from the bottom of the garden.  As demonstrated in the video, this isn't the case in Corona.  It might like look matt black metal up close, but gloss black metal from far away.  Unless of course you start adjusting blur values.  The key here is that the other engines, FStorm and Scanline give consistent results regardless of the blur value.  The problem is highlighted when we're creating shaders using things like 2D Pan and Zoom, making sure the material is looking nice, only then to zoom back out to normal render resolution and it looks completely different and all that nice detail/finish that you've spent a while getting right, is gone.  Regardless of blur value, a material shouldn't look like a completely different finish depending on the distance they're viewed from imo.

2022-12-12, 15:27:33
Reply #14

lupaz

  • Active Users
  • **
  • Posts: 951
    • View Profile
Regardless of blur value, a material shouldn't look like a completely different finish depending on the distance they're viewed from imo.
Are you willing to accept a massive spike in render times?
In Fstorm they reduce blur too to achieve this, if I'm not mistaken. You can't remove filtering on everything by default. That's insane.

2022-12-12, 15:32:56
Reply #15

dj_buckley

  • Active Users
  • **
  • Posts: 872
    • View Profile
I'd take accuracy over speed every time.

Or should I say "for an engine that has a strong focus on realism, i'd take realism over speed every time"
« Last Edit: 2022-12-12, 15:36:44 by dj_buckley »

2022-12-12, 16:07:37
Reply #16

Basshunter

  • Active Users
  • **
  • Posts: 279
    • View Profile
Hi all, first of all, I would really appreciate changing the thread title. "So broken" is not really true.
Corona bump looks completely off once you move the camera away form the object and you say it's not broken?

On the other hand, we are not getting many reports like this, so it can't be that bad. ;)
Wow

If you have some examples where the current behavior fails, please send them over - we are always happy to investigate, offer some workarounds, and log specific cases for our devs to review.
Did you even see the video?

2022-12-12, 16:12:44
Reply #17

dj_buckley

  • Active Users
  • **
  • Posts: 872
    • View Profile
Did you even see the video?

Lol, that was my first thought.  Erm .... every example

2022-12-12, 16:44:22
Reply #18

TomG

  • Administrator
  • Active Users
  • *****
  • Posts: 5434
    • View Profile
Yes, the video was watched - it just helps speed things if you already have an existing scene where the problem is known to occur for sure, rather than have us set out trying to create something from scratch (also it often helps if it is a "real world" case scenario so we know we are testing within the kinds of situations users run into, versus "here's a teapot on a plane").
Tom Grimes | chaos-corona.com
Product Manager | contact us

2022-12-12, 16:45:55
Reply #19

TomG

  • Administrator
  • Active Users
  • *****
  • Posts: 5434
    • View Profile
On the broken, it is not broken, it is as intended for render speed, so it was a choice we made back in the day. That said, sometimes that isn't the balance a user wants between speed and result, so we can take a look into the (non-trivial, actually quite complex) situation on what could be done instead.
Tom Grimes | chaos-corona.com
Product Manager | contact us

2022-12-12, 16:47:00
Reply #20

piotrus3333

  • Active Users
  • **
  • Posts: 230
    • View Profile
As @Juraj mentioned - you can just turn off tex filtering. This used to be my solution to this issue for years in VRay. I can't see how Corona would have more trouble with lack of filtering than VRay did.
Marcin Piotrowski
youtube

2022-12-12, 17:55:50
Reply #21

maru

  • Corona Team
  • Active Users
  • ****
  • Posts: 12711
  • Marcin
    • View Profile
Hi all, first of all, I would really appreciate changing the thread title. "So broken" is not really true.
Corona bump looks completely off once you move the camera away form the object and you say it's not broken?

If it was "broken" then we would be getting tens of reports about it every day. It has been working like this since 2014 (or maybe even earlier) and still there are artists creating awesome works using Corona.

Quote
On the other hand, we are not getting many reports like this, so it can't be that bad. ;)
Wow
I agree.


Quote
If you have some examples where the current behavior fails, please send them over - we are always happy to investigate, offer some workarounds, and log specific cases for our devs to review.
Did you even see the video?

Yes, I watched the whole thing. Did you read my whole previous post?

Quote
Did you even see the video?

Lol, that was my first thought.  Erm .... every example

Once again:

- This is already reported. Our developers are aware of it. It is an issue and the current behavior can be improved - I completely agree.
- Let me repeat: If you have some examples where the current behavior fails, please send them over - we are always happy to investigate, offer some workarounds, and log specific cases for our devs to review.
- The more scenes and examples we have, the higher the chance the we will improve something faster. It has always been that way.


Thanks in advance!
Marcin Miodek | chaos-corona.com
3D Support Team Lead - Corona | contact us

2022-12-12, 18:13:42
Reply #22

dj_buckley

  • Active Users
  • **
  • Posts: 872
    • View Profile
Maru - without getting petty ...

Your point about getting tens of reports every day is very naive.  We're busy people, I generally don't have time to sit and prepare scenes and log reports etc etc.  And when I do, it's at the end of the day and I just want to shut down for the day.  I'd guess a lot of people are seeing the issue but come up with their own workarounds/temporary fixes - this doesn't mean the problem doesn't exist. 

I've mentioned it a number of times in the past (including my own thread that I linked to with lots of examples querying the filtering etc etc). 

It's quicker to 'fudge' things ourselves, than it is to prepare/upload a scene, log a report and wait for a response/fix.  Admittedly we should make time to log reports after the fact, but using myself as an example, that can be weeks later, by which time I've forgotten about it because I "fixed" it myself weeks ago.  I then only remember it the next time I encounter the issue, but by that point I'm back at the start of the cycle and I'm mid-project, don't have time etc etc.  A lot of us don't have teams we can rely on to complete the work, while we spend days troubleshooting issues, so a temporary fudge is the next best thing.

Not only that, but some people either won't notice or won't care.  But again this doesn't mean it doesn't exist.

And yes, I did read your whole post, it doesn't mention the video or watching the video anywhere in it, so apologies for the incorrect assumption that you might not have watched it.

EDIT: I should have some time this evening, so I'll try and prepare an example
« Last Edit: 2022-12-12, 18:20:17 by dj_buckley »

2022-12-12, 18:56:47
Reply #23

Basshunter

  • Active Users
  • **
  • Posts: 279
    • View Profile
In fact, waiting for tens of reports before something can be called a problem or broken (you name it) is actually very unrealistic. Sometimes people can't just detect the source of a problem even when they feel something is wrong. Some of them don't even use this forum.

I have a wonderful designer on my charge and after checking that video, he mentioned that he had always felt something was wrong with the materials. He couldn't get consistent results after putting the assets in the scene. They just looked bland and too polished sometimes, even when he had just spent a lot of time tweaking them. But he didn't know exactly what the problem was. The same thing happened to me all this time too. We just couldn't tell what was wrong. We never imagined that Corona could be sacrificing so much accuracy and realism in order to make the engine faster.

 
« Last Edit: 2022-12-12, 19:29:18 by Basshunter »

2022-12-12, 19:24:19
Reply #24

dj_buckley

  • Active Users
  • **
  • Posts: 872
    • View Profile
I have another thread on here called 'Sharpness' or something along those lines.  It's the same issue but at the time I couldn't pin point it.  So Basshunter is right I guess.

I feel a lot of corona renders lack a certain 'clarity' and it's coming from things like this.

As I've already highlighted, when you're building and testing materials close in, you get them looking nice only for them to change in the final render.  When you've done this across an entire scene and then you zoom out for the final render it's quite apparent.

Why do zoom in on objects to build shaders?  Because I'm often looking at a physical sample in my hand and can put it as close to my face as I want to see the detail, grain, how it reacts to light at different angles etc.  I'm rarely building shaders whilst looking at a finished building/interior from the perspective of my CGI camera as a reference.

2022-12-13, 00:57:46
Reply #25

shortcirkuit

  • Active Users
  • **
  • Posts: 307
    • View Profile
Would have to agree here - i often comment to colleagues about how things look Muddy at times.  This puts some clarity behind the issue.


I have another thread on here called 'Sharpness' or something along those lines.  It's the same issue but at the time I couldn't pin point it.  So Basshunter is right I guess.

I feel a lot of corona renders lack a certain 'clarity' and it's coming from things like this.

As I've already highlighted, when you're building and testing materials close in, you get them looking nice only for them to change in the final render.  When you've done this across an entire scene and then you zoom out for the final render it's quite apparent.

Why do zoom in on objects to build shaders?  Because I'm often looking at a physical sample in my hand and can put it as close to my face as I want to see the detail, grain, how it reacts to light at different angles etc.  I'm rarely building shaders whilst looking at a finished building/interior from the perspective of my CGI camera as a reference.

2022-12-13, 13:49:14
Reply #26

Maybejensen

  • Active Users
  • **
  • Posts: 43
  • MaybeJensen - Denmark
    • View Profile
    • Maybejensen
Yeah microdetail is always problematic. Reduce filtering in either map (native or Corona, or bumpconverter node) and you get possible artifacts. Don't, and your detail is very much angle and resolution dependent. I don't like any filtering (I don't do animations though) but Bump/Normal can stop functioning without filtering. I've also been interested in Vray's elliptical filtering mode.

A solution that worked for me is to render quite high-res. You don't need to multiply your render-time in order to do so, down-sampling of noisier high-res files to lower resolution clears some of that noise. Also, denoised high-res file for most part looks better then undenoised lower-res file.

Possible solution for accurate detail vs animation smoothness is to use Devel/Debug menu override between these modes. There is no filtering option which can be default for stills.

I also don't use native max noise in bump, or much at all. I rather triplanar noise bitmap for more consistent result across resolution. The F-Storm is using its own noise map for good reason.
Very interesting. What do you consider high-res, 6k+?
MAYBEJENSEN I Working on something I  Ryzen 3950x / RTX 3080

2022-12-17, 08:01:33
Reply #27

DPS

  • Active Users
  • **
  • Posts: 118
    • View Profile
+1 for not agreeing with the “if people aren’t complaining then it must be ok”.

In this instance I can at least see why it was done but sometimes we just assume it works.

Sometimes it’s a stupid thing like uvw randomisation doesn’t work with certain shader setups. You’ll spend an age dicking around and then eventual give up and fudge it and assume that it must be user error.
Specs: AMD 1950X, Aorus Gaming 7 x399, 64GB RAM, 1080ti. Win10, Max 2017, Corona 1.7.3

2022-12-19, 08:09:14
Reply #28

danio1011

  • Active Users
  • **
  • Posts: 361
    • View Profile
+1 for not agreeing with the “if people aren’t complaining then it must be ok”.

In this instance I can at least see why it was done but sometimes we just assume it works.

Sometimes it’s a stupid thing like uvw randomisation doesn’t work with certain shader setups. You’ll spend an age dicking around and then eventual give up and fudge it and assume that it must be user error.

Yes, agreed. For better or for worse my assumption often is that the software is right and I am wrong.  Plus I am busy, so I can’t report a hypothetical issue.

For what it’s worth we always tell junior staff to be careful with Bump in Corona because it’s unpredictable and not that great.  Don’t get me wrong, we LOVE corona and all its features and it’s our primary engine.  But bump is not its highlight in our experience.  When I reduce blur it is better but sometimes kind of ‘rough.’  Anyway, would be cool to see this revisited by the dev team…maybe an alternate filtering method?

2022-12-19, 11:14:06
Reply #29

maru

  • Corona Team
  • Active Users
  • ****
  • Posts: 12711
  • Marcin
    • View Profile
+1 for not agreeing with the “if people aren’t complaining then it must be ok”.

Yes, agreed. For better or for worse my assumption often is that the software is right and I am wrong.  Plus I am busy, so I can’t report a hypothetical issue.

Guys, can you please explain who and where exactly said "if people aren't complaining then it must be ok"?

Can you please carefully read my whole post here https://forum.corona-renderer.com/index.php?topic=38682.msg207109#msg207109
and here (especially the bold points at the end) https://forum.corona-renderer.com/index.php?topic=38682.msg207147#msg207147

I literally said that we are aware of this issue and would love to fix it. The only thing I do not agree with is calling bump mapping technique in Corona "so broken".


Marcin Miodek | chaos-corona.com
3D Support Team Lead - Corona | contact us

2022-12-19, 11:55:40
Reply #30

piotrus3333

  • Active Users
  • **
  • Posts: 230
    • View Profile
Yes, agreed. For better or for worse my assumption often is that the software is right and I am wrong.  Plus I am busy, so I can’t report a hypothetical issue.

For what it’s worth we always tell junior staff to be careful with Bump in Corona because it’s unpredictable and not that great.  Don’t get me wrong, we LOVE corona and all its features and it’s our primary engine.  But bump is not its highlight in our experience.  When I reduce blur it is better but sometimes kind of ‘rough.’  Anyway, would be cool to see this revisited by the dev team…maybe an alternate filtering method?

How about explaining clearly how texture filtering works? I bet this would be much more beneficial to junior staff than „it’s unpredictable and not that great”.
Marcin Piotrowski
youtube

2022-12-19, 12:28:07
Reply #31

philipbonum

  • Active Users
  • **
  • Posts: 73
    • View Profile
I've also noticed this, and it was very apparent when I compared a metal ball with scratches in "identical" scenes with F-storm, Corona, and Octane. I don't remember how Octane fared, but I do remember how well F-Storm did bump mapping, and even renders it faster because of a seemingly superior adaptive sampler(?)

I would also like this to be better in Corona if possible. I'm not sure if I tested this with low filtering, so it might be that this fixes everything, but maybe

On the other hand, I've had a lot more luck when using normal maps instead of bump maps.

PS: I'm not saying FStorm is faster at rendering, but it was faster on this very specific high contrast scenario(dark interior box, 1 strong light coming from a "window") And as far as I know, FStorm is still missing a denoiser...

« Last Edit: 2022-12-19, 12:38:12 by philipbonum »

2022-12-19, 13:09:49
Reply #32

dj_buckley

  • Active Users
  • **
  • Posts: 872
    • View Profile
+1 for not agreeing with the “if people aren’t complaining then it must be ok”.

Yes, agreed. For better or for worse my assumption often is that the software is right and I am wrong.  Plus I am busy, so I can’t report a hypothetical issue.

Guys, can you please explain who and where exactly said "if people aren't complaining then it must be ok"?

Can you please carefully read my whole post here https://forum.corona-renderer.com/index.php?topic=38682.msg207109#msg207109
and here (especially the bold points at the end) https://forum.corona-renderer.com/index.php?topic=38682.msg207147#msg207147

I literally said that we are aware of this issue and would love to fix it. The only thing I do not agree with is calling bump mapping technique in Corona "so broken".

In post #10 on this thread, the very one you just linked to, you said "On the other hand, we are not getting many reports like this, so it can't be that bad. ;) " - appreciate the winky face at the end suggests it's said tongue in cheek, but still ...

I assume people are saying Corona bump is broken is purely because that's how it's presented in the initial video.  In which case, it does indeed look broken wehn compared to FStorm and even Scanline, where it works consistently and exactly as I'd expect it to work.

To reiterate, a shader shouldn't look like a completely different finish (gloss or matt) depending on how close to it you are or what your filtering settings are.  This is what is happening in Corona, in the FStorm and Scanline examples, the finish looks the same regardless which is how it should be.  Gloss is gloss and matt is matt.

2022-12-19, 13:50:18
Reply #33

philipbonum

  • Active Users
  • **
  • Posts: 73
    • View Profile
Recreated my scratched chromeball scene again, and:
Fstorm:
A lot better looking bump, much more fine details, only creates bugs when bump is way beyond any normal use case
It does not seem like there's any filtering/blur on textures by default. Turning this up creates similar bump as in Corona, but without disappearing from far away.
Adaptive sampling is very aggressive on the scratches, making them show up almost immediately, but slower at removing the fine noise all over the image

Corona:
Filtering on by default, turning it "off" (0,01) produces much better results, and keeps it looking correct from far away
Not as good bump, trying to match the amount of bump/scratches in FStorm produces a "ring" effect
Adaptive sampling not really focusing on the scratches(?), so it needs a lot more samples, but at the same time the entire image becomes progressively better.

So in short:
Turning "off" filtering on textures is as always a good thing to do, maybe get in the habit of always doing this on bump? Increased rendertimes?
Room for improvement on bump in Corona in general. Take a look at the competition, always good to have something to work towards.
Maybe improve on the Adaptive sampler, it's very handy if it focuses on texture details like the scratches, aka quick feedback when editing materials

PS: Not sure if it's the Adaptive sampler that is deciding what to focus on when rendering, but that is my understanding of the feature.

2022-12-19, 15:34:45
Reply #34

Basshunter

  • Active Users
  • **
  • Posts: 279
    • View Profile
To reiterate, a shader shouldn't look like a completely different finish (gloss or matt) depending on how close to it you are or what your filtering settings are.  This is what is happening in Corona, in the FStorm and Scanline examples, the finish looks the same regardless which is how it should be.  Gloss is gloss and matt is matt.

This. I could not agree more.

2022-12-19, 17:14:31
Reply #35

danio1011

  • Active Users
  • **
  • Posts: 361
    • View Profile
Yes, agreed. For better or for worse my assumption often is that the software is right and I am wrong.  Plus I am busy, so I can’t report a hypothetical issue.

For what it’s worth we always tell junior staff to be careful with Bump in Corona because it’s unpredictable and not that great.  Don’t get me wrong, we LOVE corona and all its features and it’s our primary engine.  But bump is not its highlight in our experience.  When I reduce blur it is better but sometimes kind of ‘rough.’  Anyway, would be cool to see this revisited by the dev team…maybe an alternate filtering method?

How about explaining clearly how texture filtering works? I bet this would be much more beneficial to junior staff than „it’s unpredictable and not that great”.

We do explain filtering, too, of course.  That's kind of the point of this whole thread and also my comment:  even with a basic understanding of filtering, bump at glancing angles still acts in such a way as to deserve special treatment\explanation\occasional avoidance.  I'm thinking specifically about tree leaves.  We often leave bump off altogether for distant trees because we can get a natural look without it and find it to be more predictable when it comes to specularity (not to mention faster).  Again, YMMV but that's our experience and it seems I'm not the only one.

2022-12-20, 12:34:42
Reply #36

l.croxton

  • Active Users
  • **
  • Posts: 60
    • View Profile
Coming from FStorm and moving over to Corona (various reasons) I complete agree that the texture filtering/blurring as its currently defaulted too is more of hinderance than a net positive in my experience. Simply put I couldn't figure out why my renders were just looking better/sharper and then I just happened to try removing the blur and viola it was all good again. Not to say I don't use the blur in any of my renders in Corona, I tend to use it to help smooth out displacement/bump if I need them to be smoother but outside of that, I pretty much just remove filtering on anything.

Maybe a request could be made in the Corona converter that there is a "remove blur value" or "set blur to 1 or 0.1 or 0.01" ? which could also be tied to, all of scene or just selected.

2022-12-20, 13:56:19
Reply #37

romullus

  • Global Moderator
  • Active Users
  • ****
  • Posts: 8779
  • Let's move this topic, shall we?
    • View Profile
    • My Models
Maybe a request could be made in the Corona converter that there is a "remove blur value" or "set blur to 1 or 0.1 or 0.01" ? which could also be tied to, all of scene or just selected.

Discover Batch Material Editor and you will barely need anything else. https://forum.corona-renderer.com/index.php?topic=12857.0
I'm not Corona Team member. Everything i say, is my personal opinion only.
My Models | My Videos | My Pictures

2023-01-21, 22:27:13
Reply #38

mrsacan

  • Active Users
  • **
  • Posts: 120
    • View Profile
I was planning to create a thread about this but I learned the reason when I see this thread, as I see it was mentioned before.
I was wondering why one of my materials look different when distance (so, resolution) changes.



But in my case, this is not default value, it's the opposite way, I changed blur value to 20 (to smooth a sharper bump image), but I think it shouldn't depend on resolution/distance.
This is a serious issue imho.

2023-01-21, 23:46:56
Reply #39

romullus

  • Global Moderator
  • Active Users
  • ****
  • Posts: 8779
  • Let's move this topic, shall we?
    • View Profile
    • My Models
But in my case, this is not default value, it's the opposite way, I changed blur value to 20 (to smooth a sharper bump image), but I think it shouldn't depend on resolution/distance.
This is a serious issue imho.

I think you simply are using wrong feature. If you want blur that won't change its strength depending on resolution, then you need to set blur to the minimum and use blur offset instead. You will need to use Max bitmap though, since Corona bitmap doesn't have this feature.
I'm not Corona Team member. Everything i say, is my personal opinion only.
My Models | My Videos | My Pictures

2023-01-22, 11:26:00
Reply #40

mrsacan

  • Active Users
  • **
  • Posts: 120
    • View Profile
I think you simply are using wrong feature. If you want blur that won't change its strength depending on resolution, then you need to set blur to the minimum and use blur offset instead. You will need to use Max bitmap though, since Corona bitmap doesn't have this feature.

I'm not sure what you mean, blur option works as I expected. Getting different results from different distances/resolutions is a completely different issue.


2023-01-22, 16:01:58
Reply #41

romullus

  • Global Moderator
  • Active Users
  • ****
  • Posts: 8779
  • Let's move this topic, shall we?
    • View Profile
    • My Models
Did you even read my message above? It has attached screenshot too. I will repeat it again - you're using the wrong tool for your task. Despite the name, blur in 3ds Max bitmap (and Corona bitmap) is not the same as blur in Photoshop. It acts more like an antialiasing - the smaller your texture is in the rendered image, the more it gets blurred. As i already said, if you need blur in traditional sense, you should use blur offset, or simply use photoshop and blur the texture permanently.

You can read about blur and blur offset in 3ds Max documentation: https://help.autodesk.com/view/3DSMAX/2023/ENU/?guid=GUID-8AE3643F-BDB4-498B-B220-92646FC8A562
I'm not Corona Team member. Everything i say, is my personal opinion only.
My Models | My Videos | My Pictures

2023-02-03, 18:28:28
Reply #42

Juraj

  • Active Users
  • **
  • Posts: 4743
    • View Profile
    • studio website
Can fully second what Romullus says, the names are weird and not what is commonly used as terminology elsewhere. Offset is very finicky though but I use it for displacement maps.
Please follow my new Instagram for latest projects, tips&tricks, short video tutorials and free models
Behance  Probably best updated portfolio of my work
lysfaere.com Please check the new stuff!

2023-05-20, 17:42:34
Reply #43

Mr.Max

  • Active Users
  • **
  • Posts: 76
    • View Profile
I'm not sure if this was mentioned before but Renderman fixed it using a "Bump to Roughness" map that makes sure you will get good result from any distance.

also the recent update for VRay For Maya seems to introduce similar solution and according to Vlado when I've asked if it is the same and when we will see it in Max her replied
 " It is the same concept, yes - although the implementation is different. It is still experimental; if it works well, we will add it to other integrations."
https://docs.chaos.com/display/VMAYA/VRayBump2Glossiness

Simply, I love to put pixels together! Sounds easy right : ))
https://www.behance.net/NawrasRyhan

2023-05-22, 12:27:49
Reply #44

romullus

  • Global Moderator
  • Active Users
  • ****
  • Posts: 8779
  • Let's move this topic, shall we?
    • View Profile
    • My Models
+1 for Bump to Roughness. Seems very nice idea to me.
I'm not Corona Team member. Everything i say, is my personal opinion only.
My Models | My Videos | My Pictures

2023-05-22, 13:52:16
Reply #45

lupaz

  • Active Users
  • **
  • Posts: 951
    • View Profile
+1 bump to roughness

2023-05-22, 15:06:08
Reply #46

philipbonum

  • Active Users
  • **
  • Posts: 73
    • View Profile

2023-05-22, 22:15:02
Reply #47

marchik

  • Active Users
  • **
  • Posts: 256
    • View Profile
definitely +1 for bump to roughness!

2023-05-22, 23:57:10
Reply #48

Aram Avetisyan

  • Corona Team
  • Active Users
  • ****
  • Posts: 543
    • View Profile
We had this logged a while ago, in multiple ways/tasks.
Be sure that it is logged, and your votes can push it closer to better chances of actual implementation.
You can add/vote for it here: https://forum.corona-renderer.com/index.php?topic=96.0

(Internal ID=494856762)

Aram Avetisyan | chaos-corona.com
Chaos Corona Support Representative | contact us

2023-05-23, 19:31:24
Reply #49

Basshunter

  • Active Users
  • **
  • Posts: 279
    • View Profile
Be sure that it is logged, and your votes can push it closer to better chances of actual implementation.
You can add/vote for it here: https://forum.corona-renderer.com/index.php?topic=96.0

Does it even have an impact on what devs decide?
I mean, things like GPU/CPU hybrid rendering and Vantage support have been the most requested feature for a long a time but nobody seems to be listening to that.

2023-05-23, 20:08:46
Reply #50

TomG

  • Administrator
  • Active Users
  • *****
  • Posts: 5434
    • View Profile
It plays a part in what is decided, yes. But only a part, and there will be other reasons that play into what gets selected and what doesn't. That said your examples are about the worst to pick :) e.g. rewriting code to work on GPU is a massive undertaking, which obviously is a big negative against developing that, no matter how many vote for it. But always vote for what you want regardless of that, and know it does have an effect on what gets picked.
Tom Grimes | chaos-corona.com
Product Manager | contact us

2023-05-24, 18:54:09
Reply #51

lupaz

  • Active Users
  • **
  • Posts: 951
    • View Profile
We had this logged a while ago, in multiple ways/tasks.
Be sure that it is logged, and your votes can push it closer to better chances of actual implementation.
You can add/vote for it here: https://forum.corona-renderer.com/index.php?topic=96.0

(Internal ID=494856762)

I don't see this in the list. And I don't see a way of adding other items to the list.