Messages

1

[Max] I need help! / Re: Color accuracy

« on: Yesterday at 22:45:12 »

Corona did as best as it could to support ACES (whatever users had in mind saying it) in the meantime, on the go.

First it was the limitation of the host app (no proper color management), then it was its half baked state.

Corona had wide gamut for rendering since the very early days. Even with 3ds Max being just gamma managed, we added ACEScg as internal rendering space some time ago (maybe Corona 10 or older, cannot quite remember). This would give slight differences in color, the most significant being in colored medium. See this comparison. Overall, the differences between Wide RGB and ACEScg are very subtle, and this shows that Corona's internal rendering color space was very robust even before ACES was "cool".

Then we also implemented ACES OT operator. This specifically brought better highlight (including colored) handling. See this comparison.

It might have left unnoticed because, in my opinion, archviz is not a branch that would had seen significant boost from it. It just became a better standard, and render engines tried to adopt it as good as possible.

If you want to help archviz, Corona should finally support ICC profiles in the VFB as final color transform. For all the PS guys, Aces might be nice for it tonemapping, but as far as color management is concerned, it's not helping much.

We went slightly off topic though, OP asked for shortcomings of sRGB and workflows for proper material/surface capturing.

2

[Max] I need help! / Re: Color accuracy

« on: Yesterday at 11:54:04 »

This post warms my heart - really, good to read it drives others mad, too.

Two in-depth articles from a longtime Max user about PBR and some of its assumptions and pitfalls, and practical solutions:
https://www.racoon-artworks.de/blog_PBRfromrulestomeasurements.php
https://www.racoon-artworks.de/blog_PBRshootingandcalibrating.php

Getting the right material properties is hard without a proper device. A colorimeter will only give you a reflected color value without any other info about reflectance and its behavior. The there's the materials surface which will affect all incoming/outgoing light and will produce different results for lighting and viewing angles.

Then there's the renderer - you can't really be sure how realistic it'll model the reflectance behavior when it comes to surface structure, how bump maps work in renderers is generally very simplified and will not reproduce real life accurately, and with texture filtering you can not really tell what it'll do). Rough diffuse materials are really a topic on its own with hardly any renderer caring about it.

As for sRGB, it's only getting worse from here. I'd say the range of colors in RAL and Pantone that can't be reproduced in sRGB may even be about 50%, maybe even more. I have not once come across a site that will tell you which space of RGB they assume for the values, and I'm pretty sure it's because they know it's impossible and just tell you a number close enough. Some vendors will give you LAB colors which is another can of worms because the scientific LAB space is not the LAB you'll find in Photoshop.

Broad topic, and then there are clients who will view your results on an uncalibrated display one day and tell you it's too dark, and the next they'll look at it on their mobile and tell you it's too bright and could be less saturated :D

I have worked in pre-press for some years and looking back I wish people in all places of the production chain (software vendors, too) would care about this today as people did 20 years ago when they printed stuff on paper.

3

[Max] I need help! / Re: Creating a terrain with Corona displace modifier - viewport view

« on: 2025-03-11, 11:25:32 »

You can keep using one mesh - with the standard Displace modifier for the mesh in the viewport and CoronaDisplacementMod for rendering.
When you right-click on the Displace modifier (and the Turbosmooth mod if you wish), you can set it to 'Off in Renderer', and set the Corona modifier to 'Off in Viewport' the same way.
That way, each one will be passed to either viewport or renderer, making it possible to keep working with one mesh.

Not sure this is what you're asking, but it sounds like it is.

4

[Max] I need help! / Re: Chaos corona livense not found

« on: 2025-03-10, 14:13:49 »

Working again, thank you.

It's probably time to learn from this issue (and so many before) and improve the licensing system, some suggestions:
- I had ISP connectivity issues in the past and every time my license was wonky for a few days. A licensing system that checks the license and then stores its status for a day or two would already help a lot
- let us work on materials even with the system not being able to retrieve a valid license

Really, anything that actually pays respect to the fact that we're paying upfront for 1 year of undisturbed usage of your software. I'm sure others have own thoughts to add.

5

[Max] I need help! / Re: Chaos corona livense not found

« on: 2025-03-10, 13:31:14 »

Mine is #355195

Going by the number of users posting about the same problem at he same time it's a problem on your end. Asking us to submit a ticket is just not the way to go about this and, no matter the way you look at it, won't help to solve it.

And really, this shitty licensing system (in the past and now again) leads to all kinds of issues, no way the usual text block answers will do this time.

6

[Max] I need help! / Re: Chaos corona livense not found

« on: 2025-03-10, 13:13:10 »

Yes, same here. I could access Corona normally until 12.45, then no license.
Online portal reports everything's fine so... yeah doesn't seem so.

Thanks, Chaos, good job. We're paying upfront, don't we?

7

[Max] Bug Reporting / Re: Corona renders different shading with anisotropy

« on: 2025-03-04, 16:04:41 »

Please don't rest in peace yet! :D

Glad it was helpful.

8

[Max] Bug Reporting / Re: Corona renders different shading with anisotropy

« on: 2025-03-03, 16:56:14 »

Try this - (in a temp scene or copied objects of ocurse):
- in 'advanced options' tab of the material, change 'anisotropy orientation' from local axis to UVW
- now apply a UVW mod in box mode to *all* affected objects so they share the same UV space
- make sure to use the same UV channel for both the anisotropy orientation and UVW modifier.

If the problem goes away, it means the objects have been modeled in different local axes. This happens when you start modeling one wall in the left view, another one in front/top etc. The local axis of these objects will be different and since anisotropy treats each one differently each object will reflect differently.
By using UVs as anisotropy orientation *and* making sure all objects have their UVs defined the same way by using a UVW modifier, it should render the same for all objects.

A good addition for the physical material would be to have a user 'reference node' for anisotropy orientation, that way users wouldn't have to worry, the specified reference node would then be used as axis reference for all objects using that material.

9

[Max] General Discussion / Re: Different Colors Between Corona VFB and Saved Image

« on: 2025-03-03, 13:30:55 »

Lol, I've been asking for this in some other places, too. Some time around Corona 1.4 or 2 I just gave up because I realized the team just didn't *understand* the need. For some reason, dealing with support requests, confuse users for years only to still offer nothing seemed like the better way to go about it.

Just so you know, since piotrus3333 linked to my post, it took Rotem literally a weekend to implement this in VFB+, and most of the time he spent on dealing with RGB to CMYK conversion, which we wouldn't need, let's just do RGB. And 2015?!? 10 years...

10

[Max] I need help! / Re: STANDARD SURFACE material to CORONA MATERIAL

« on: 2025-03-03, 12:28:28 »

No, Standard Surface is Arnold's own physical material, it's not the (old) default Scanline Standard. It's pretty wide spread in the Maya world but not very common for 3dsmax (mostly because Max got Arnold so late and has much less users than in Maya).

11

[Max] General Discussion / Re: Different Colors Between Corona VFB and Saved Image

« on: 2025-03-03, 12:24:42 »

My 2 cents - while Corona has followed the 3dsmax development with OCIO, you also omitted the work case most users will face just like Autodesk did, namely going to PS and work on the images - where ICC profiles count, not OCIO view transforms. OCIO might support ICCs but so far I've only seem convoluted ways to get there and it's nowhere near user friendly.

The only way to solve this really common problem would be to finally implement ICC profiles in the VFB, and embed them in the files saved.

I've been asking for this for years and I believe you really have to consider finally adding ICC functionality. It would finally make it possible to preview images the way they'd display in PS.
Most users would already be happy with only adding final VFB transform (not taking care of any input conversion for textures, or only on some general global level, not per texture).

12

[Max] I need help! / Re: CMasking masks aren't completely white

« on: 2025-02-27, 14:58:09 »

Any exposure/tone mapping involved? Sometimes I'm rendering masks 'manually' by using LightMtls to work around limitations and typically have to disable exposure/tone mapping (because I'm using the RGB output, not the alpha channel).

13

[Max] I need help! / Re: Corona Image Editor

« on: 2025-02-26, 20:57:47 »

Renaming the cxr to exr will make it open in any app that can open exr files. I'm not sure about the dynamic range though - as far as I know tone mapping will be baked in so probably no access to the full dynamic range and non-tonemapped image.

14

[Max] Daily Builds / Re: Chaos Corona 13 for 3ds Max - Daily Builds Discussion

« on: 2025-02-25, 11:34:06 »

I appreciate that software development isn't necessarily as straightforward as saying "just change it from A to B" but I'm curious to know if the QT re-write could be done in stages?

As others have mentioned the biggest impact would be the material editor change so even if just the CoronaPhysicalMtl was updated in 12u2 (or 13) and other parts of the UI followed in later versions this would already have a huge effect on productivity.

Side note, slightly related - not sure what's happening with LayerMtl but it looks like adding a new Layer to it will update all layers (probably registering/re-ordering anim tracks for all 10 layers...?) adding a lot of overhead and time until you can work again.

15

[Max] I need help! / Re: Different background image colors in rendering

« on: 2025-02-24, 21:11:04 »

In my opinion this is a problem because it becomes more difficult to find the right match when you have to insert a 3D model on a photo..isn't that the case for you too?

Yeah, it's a major pain. Not being able to match lighting/level/hues against backplates because of tonemapping that can't be worked back is really a problem in my case and almost every project suffers here because I can't be sure I'm 100% where it needs to be.

In case you wanna vote for it:
https://chaoscorona.ideas.aha.io/ideas/CMAX-I-27

For some reason, the team never properly acknowledged the need for unchanged background colors, and it surely can get complicated. But even a simple solution, even if limited, would help.
Don't get your hopes up though, people want stars and the moon in the VFB and I bet it's going to be there way sooner.