Messages

346

[Max] I need help! / Re: Round Edges Map - Physical Material

« on: 2021-07-22, 12:41:01 »

Apologies if already asked but cant find it in the search.

If you were making a material with a clear coat would you put corona round edges map in the base layer, clear coat layer or both?

Thank you in advance

Hi RenoJ, Corona Round edges will mostly work with the base bump in a case where you want two or more surfaces to look uniform/welded , but there are also cases where you'll need to apply it for both bumps, like f.e. a box or cube that needs to have its edges chamfered through the use of corona round edges.

347

[Max] I need help! / Re: What would be reflect map over here?

« on: 2021-07-22, 12:23:38 »

Hello, new user here. I m downloading one material from quixel megascans but don't know what represents reflect map on their downlaod list (picture attached)?
Normally when I use Corona I only use bitmaps for diffuse/albedo, reflect, gloss, normal and displacement. Their download list is either missing reflect map or is it called something else over there?

That would be a specular map but it needs some treatment in order to be used for IOR, I would suggest using their bridge plugin it does a pretty good job converting their presets into Corona legacy material. If you are considering on using CoronaPhysical then the entire process is much easier with a single roughness map or Spec to IOR mode.  If you require any further assistance on this please don't hesitate asking.

348

[Max] Daily Builds / Re: New Corona Physical Material (PBR) playground!

« on: 2021-07-15, 18:11:36 »

In terms of physical correctness, the previous implementation allowed for non physically plausible results, you cannot have a single surface that's rough but also highly glossy at the same time.

That reminds me, does it now work if we apply different treatment (through material ID for example) to refractive glass (with real volume/thickness) ? Most frosted glass is simply sandblasted on one side and polished on other (when it's not glued to hide the sand-blasting in middle).

I remember this always created some kind of artifacts.

I believe it's doable with no issues but, I ll try it out :).

349

[Max] Daily Builds / Re: New Corona Physical Material (PBR) playground!

« on: 2021-07-13, 14:07:23 »

Hello,

How do you deal with flossy refraction (not reflection) with the new PBR material ? In legacymtl, you have the glossiness in the refraction, but it seems to be different in the new pbr materials.

thanks

In terms of physical correctness, the previous implementation allowed for non physically plausible results, you cannot have a single surface that's rough but also highly glossy at the same time.

To achieve a form of coated frosted/etched(even sandblasted) glass you simply have to enable clear coat within CoronaPhysicalMTL, here is an example of a coated/non-coated lamp with base roughness 0.9. : https://corona-renderer.com/comparer/szNYfS

I hope this helps.

350

[Max] Daily Builds / Re: New Corona Physical Material (PBR) playground!

« on: 2021-07-09, 10:12:51 »

Today I noticed for the first time a difference in reflections when I changed the roughness IOR from 0.00 to 0.01.

I am not sure if this is already known. So sorry if this is a double post.

Simple reflective plastic material is used with no clear coat.
Everything looks fine at IOR 0.00. Once it goes above 0.01, the reflections change. It reminds of switching the reflection mode in UE4 from nonRT to RT.
Normally this wouldn't bother me at all, but I very often use a value of 0.00 to get softer highlights like from the sun. So almost all my materials are at 0.01. But this example shows why I had problems when creating my physical materials.

Please focus on the BMW badge.

UPDATE:
Did more tests and I can narrow down the cause a bit. The material does reflect an HDR in Dome mode. When the mode is set to Spherical everything is fine.

In Dome mode it seems that the lower hemisphere is displayed as black for materials with a Roughness of >0.01

UPDATE 2:
Updated with new images showing the issue with dome mode.

This was a known issue and I believe it's already addressed, unless I am missing something. Which version of Corona DB or RC you are using in these examples?

(Report ID=CRMAX-436)
Dome - (Internal id=311287120)

351

[Max] Bug Reporting / Re: Nvidia Denoiser Issue, Glitchy Render

« on: 2021-07-06, 12:07:29 »

Hi, apologies I don;t think I can upload the scene due to Project NDA.

The GPU hardware I use is Zotac 2070 Super

Is it possible that you reproduce the issue in a non-NDA scene, or offer some reproduction steps?

Regards,

352

[Max] Resolved Bugs / Re: Caustics collapse into a pole/pinching when scene scale is huge

« on: 2021-07-01, 13:16:57 »

Sent you the team's compiled list of feedback :)

Once again thank you very much for the detailed feedback. Marcin is on it :).

353

[Max] Daily Builds / Re: New Corona Physical Material (PBR) playground!

« on: 2021-07-01, 12:19:05 »

In your freshdesck website you have considered:

0.70 μm for Red, 0,55 μm for Green, 0.45 μm for Blue

But for wideRGB gamut like that:

https://upload.wikimedia.org/wikipedia/commons/1/1d/CIExy1931_AdobeWGRGB.png

Green belongs to 0,52 and blue 0,390. why is there this discrepancy?

Thanks

I don't believe input values can be absolute, most approximations around the limits of the visible light spectrum will work just fine depending on, as said previously, "preferred visual outcome and on how much oxidation is introduced on the metal's surface" (excluding metal alloys - impure metals - although oxidization implies impurity, but let's just leave it at that).

Let's take the example of Pure Gold (Au) -  Generally, its electrons move at relativistic speeds (especially on its outer surface). The outer surface is responsible for its chemical behaviour and a lot of physical properties, including color. The human eye spectrum varies from wavelengths - approximately 390 nm (blue) to 700 nm (red), gold absorbs a lot of the low wavelengths (blue). So we’re left with the opposite (yellow - towards red when it's pure).

Pure Gold (au) does not get oxidised, hence pure gold should not appear green-ish, it should mostly reflect yellow with a minuscule tint of red. The following comparison showcases exactly just that, Complex IOR of Gold with 0.7-0.55-0.45 against sRGB limited values of 0.61-0.56-0.47: https://corona-renderer.com/comparer/RRnUev (Both outcomes can be described as Gold, but when thinking of recreating Pure Gold we should compensate for corresponding wavelength inputs, in order to remove the greenish tint)

So, to summarize, any approximations between 0.70 μm for Red, 0,55 μm for Green, 0.45 μm for Blue (~ +- within reason) will work great for most pure metals, in some cases, you might want to experiment with different wavelengths. I hope this helps, and it actually makes sense!

354

[Max] Daily Builds / Re: Corona Renderer 7 for 3ds Max - Daily Builds Discussion

« on: 2021-07-01, 09:25:42 »

https://photos.app.goo.gl/J9Bzt8fGwu53knvv9
Rc4 Error.

tested in several scenes!

Please submit a ticket, consider archiving a scene where the issue is reproducible for you and if possible include your 3dsMax minidump produced after the crash. For submitting a ticket please check the link on my footer below.

Thank you

355

[Max] Daily Builds / Re: New Corona Physical Material (PBR) playground!

« on: 2021-06-29, 10:36:32 »

Hello, how have you decided the wave values ​​for RGB that are put in the complex IOR that appear here https://coronarenderer.freshdesk.com/support/solutions/articles/12000079075-how-to-use-complex-ior-for -coronaphysicalmtl-? Shouldn't they be equivalent to the ends of the sRGB triangle where Red corresponds to 0.65nm for example? (see link of the image)

https://upload.wikimedia.org/wikipedia/commons/thumb/8/8f/CIExy1931_sRGB.svg/1200px-CIExy1931_sRGB.svg.png

Thanks!

Hi n2graf, please note that Corona is using color space with a wider gamut than sRGB, you will also find that approximations around 0.7-0.55-0.45 can produce a more favoured outcome depending on how much oxidation is introduced on the surface, and the type of metal.

356

[Max] Daily Builds / Re: Aerial Perspective Playground !

« on: 2021-06-25, 11:31:40 »

Using RC3 and the green tint is gone. However it tints now the scene in purple.. especially visible in refractions. Even if you activate the effect, then turn down to 0 the scene is still affected/tinted in purple slightly.

Thanks Duron, we are aware of the issue and it's being investigated further.

357

[Max] Resolved Bugs / Re: Caustics collapse into a pole/pinching when scene scale is huge

« on: 2021-06-25, 11:12:55 »

Good to know :) There's probably some specific things that the guys here could go into details on as well. I might ask around and get a little list together for you of issues we've found relating to caustics/dispersion specifically, if that would be helpful?

Cheers,

That would be very helpful, much appreciated! Feel free to contact me or anyone from the support team with the list and we will pass it through!

Cheers,

358

[Max] Resolved Bugs / Re: Caustics collapse into a pole/pinching when scene scale is huge

« on: 2021-06-24, 15:48:02 »

Excellent stuff. This has been a challenge on loads of current projects so it'd be great to get a fix!

While you're at it - we've found that it might be somewhat related to the photon count needing to be higher on higher-res scenes, or larger-scale scenes, where what you really want is to fire as many caustics photons into the immediate scene. I wonder if you could build in a distance/scale limit, so the vast majority of caustics are calculated in the camera's view, and anything beyond that, or beyond a distance we can control, start to fall off.

And as above, when you go from a 2k test to a full res render, it seems you need to really crank the number of photons to get a good, clear result. This should not be necessary, and would ideally also be fixed.

Cheers!

Lastly, as a PS... I know it's been requested a thousand times, but we really would looooove a simple include/exclude mode for receiving caustics. Or perhaps you could consider some kind of "caustics blocker" material. We actually tried making one, which does work, using a kind of invisible-to-camera approach, but it doesn't fully work, and it ends up darkening inside water and wouldn't work for most use cases. But something like your corona portal that does a similar thing for caustics and controls them not to fire past the object might help if a proper include/exlude method is not possible/feasible.

Thanks again for all the feedback Alex, I believe we have all issues/requests logged I will further update the current ones and fill in anything missing. Caustic improvements are planned for v8 (https://trello.com/b/EfPE4kPx/corona-tentative-road-map-3ds-max) so hopefully, most of the current issues will be improved.

(Internal ID=566135445)

359

[Max] Daily Builds / Re: Corona Renderer 7 for 3ds Max - Daily Builds Discussion

« on: 2021-06-24, 12:55:43 »

@team, i think there's a lot of issues and questions about the new aerial perspective, can we have dedicated topic on this subject please?

It is on! https://forum.corona-renderer.com/index.php?topic=33613.msg186845#msg186845

360

[Max] Daily Builds / Aerial Perspective Playground !

« on: 2021-06-24, 12:17:47 »

It's time for a new playground, this time regarding the new Improved Sky -  Altitude & Haze (Aerial Perspective). Please feel free to test this out and post your creations, If you have any questions, requests or critique regarding this feature please share them with us.  The latest stable version of it can be found here: https://www.dropbox.com/s/aul162xh65q0vjx/corona-7-3dsmax-RC3.exe?dl=1



Basic details
Upon adding a Corona Sun & Sky, navigate to your slate material editor and paste or move your corona sky there. Within the Corona Sky Texmap, there is a section called  Improved Model.
It is now possible to set your observer altitude in meters, higher values of this parameter will make the sky clearer and the horizon line less sharp. Next to altitude, you will find the Volume effect(haze), if true it enables a volumetric effect based on atmospheric settings from the current skymap. As expected, higher values of the Volume effect make the haze more dramatic/dense.



Happy Rendering!