Topics

1

[Max] I need help! / Lens tilt/swing?

« on: 2023-12-15, 16:01:33 »

Hi!

I suspect this is way too niche and also something that will fly over most heads.
But I wonder if someone with insight into writing a ray/pathtracer (preferably a developer of corona ;) ) could answer if it would be possible to implement lens tilt/swing in order to change the angle of the focus plane according to the scheimpflug principle?

Doing product shots in Corona, I use a lot of lens shift to obtain desired perspectives/projections - as one would do in a real studio. And it would be cool if I could have all the tools of a physical camera in corona too.

Using tilt/swing in real life is really really hard. But having focus plane preview on the corona cam, it would be a nice tool to have up my sleave.


</ weird question that probably doesn't deserve much attention in the grand scheme of developing corona render>

2

[Max] I need help! / Corona Image Editor writes (possibly) corrupt TIFF

« on: 2023-11-16, 08:50:38 »

Hello,

Is there any known limitation to resolution or file size when it comes to tiff?

I've rendered to CXR, and I save as TIFF from Corona image editor, and suddenly nothing will open the files. Saving as PNG works. The only thing I have changed in the setup, apart from geometry and materials is that I bumped the resolution from 11600x7733px to 12000x8000px. Either the output is corrupt or Photoshop can't read it. But photoshop can create, save and read a Tiff of that size so I don't think that's the problem.

3

[Max] I need help! / filtering, bump and roughness

« on: 2023-10-09, 14:49:30 »

Hi!

I remember seeing threads about how Corona takes shortcuts with filtering so we can how our nice and quick renderings, and that this usually isn't a problem in most images/scanarios. I just lost my perfectly tweaked highlights in my powder coating when going from testrenders to rendering 11,6K. Test rendering at that size isn't realistic, hardly even with regions.

What should I do to make sure my highlights have the same roughness/bump no matter what render size? And how bad will the penalty be?

4

[Max] Feature Requests / View LUT?

« on: 2023-09-19, 14:02:29 »

I've seen on trello that VFB and color management is being worked on. So maybe this is in the works already.

I've would like to have a LUT in the VFB that doesn't get applied to the output, a "view LUT" if you will. More savvy people in the area of color management and color grading will probably have a better word for this an also want to use very specific view transform LUTs. I just want to preview my render with some extra punch, but then not have it burned in and then finesse it manually in Photoshop :)

5

[Max] I need help! / Camera and White Balance questions

« on: 2023-09-11, 12:04:26 »

Hi!

Am I getting this right? Corona ignores WB setting of PhysCamera? IR starts over as if there was a change, but nothing changes. If it's not supported could we please have an option in Tone Mapping like Photographic Exposure, to also use WB settings from the Camera? I have cameras in different places :)

BTW, I noticed Corona Camera doesn't have focus breathing? (or I can't find it)
It also doesn't let you enter or see exposure in EVs which is a con for me. I don't think I'll ever convince anyone here how useful it is. But trust me, I've worked as a photographer professionally on the side of 3d for over 15 years - it's not that I don't know how to set a camera in manual mode. Mine is parked in manual mode.

6

[Max] I need help! / Performance penalty when using Max native Physical Material?

« on: 2023-03-01, 09:53:22 »

Hi!

Corona seems to fully support the Physical Material that is native to Max. Haven't checked all the features yet. But, is there any penalty in performance when using it?

Of course I prefer the Corona Material when ever I can, if just for easy of use. But there are situation where using only Max native material and maps might be necessary. Does anyone know if I would be looking at a severe performance hit? Or are we talking about a 1% increase or something like that?

7

[Max] I need help! / Render to texture, bake to texture

« on: 2023-01-06, 16:08:20 »

I feel very stupid now, but I thought this was something that one could simply just do. I'm having a lot of trouble and I can find very little info. And I just saw this:
https://support.chaos.com/hc/en-us/articles/4528523245073-How-to-use-texture-baking-in-Corona-for-3ds-Max-
"Note: using the projection modifier is not yet supported. "

So how does the projection even work!? I get black areas where high/low intersect and I just got around this but temporarily using a push modifer to grow my low outside the high one.

And I need to get out metallic, roughness and emission too. (Haven't tried the light pass yet)

Seems like I need to convert my entire project to arnold or generic Max materials/maps and bake with arnold or something instead. I know this kind of work isn't Corona main area of expertise so maybe I am kind of stupid for not checking this in advance. Spent many days setting up photoreal renders of a product hoping to just quickly bake it :( But this feature seems only half-baked in corona ;)

8

[Max] I need help! / Camera and exposure in Corona 8 + TintOperator

« on: 2022-04-14, 11:56:59 »

It was very confusing to not be able to use photographic settings right away. Eventually found that I had to add it to the tonemapping stack. But it's kind of wierd that I can still enable simple exposure, but the spinner is greyed out and I cannot change it.

Very glad to see the term EV removed from simple exposure! This was very confusing for people when it didn't mean the same thing as it does in the rest of the photographic world.

Would it be possible to get real EVs as an option on the photo graphic exposure and/or basic photographic settings? I know Juraj told me it was an antiquated/obsolete term or something. But I think it's really wonderful way of simplyfying exposure and it's been around for ages. There's lots of reference. And it's a really excellent tool when I teach visualisation students to get them in the ball park of how much light is reasonable for a scene. Juggling shutter, aperture and ISO is too much for them. So we look at loads real world examples and what EV they were shot at. So they know a bright daylight scene is around 14 EV and an bright office interior is 7-8, and that's also good for blue hour exteriors.

And what does this really mean?

"Physical camera: The following operators are supposed to be overridden but they are not in the tone mapping pipeline: Chaos.TintOperator.Data"

I just made a phys cam and tried to render with daylight system. I don't get the error messange when I open an old scene made in Corona 7

9

[Max] Feature Requests / Nesting multi/sub in layered material

« on: 2022-03-07, 22:08:31 »

Such a boring request :) I really thought it was possible and was quite baffeled when it resulted in a warning. The other renderer can do it I believe. And it would be super practical to be able to put dirt and other stuff on top of a more complex materials. I have a terrain or some streets with sidewalks and parks, that all are defined by one big multi/sub material. Would be nice to be able to put a dirtmap on top of all of it, instead of nesting a unique material manually between each sub-material and the multi material. Can't you like programatically tell the renderer to do basically that when there's a layered on on top? Is this difficult or is there a risk of a slowdown or loops?

10

[Max] I need help! / instances, instancing and proxy

« on: 2020-01-14, 16:48:37 »

Hello!

I did some searching of course, but just got more confused about memory management with proxies.

So I'm going to ask some very simple and stupid questions here to clear this out for myself once and for all.


In Corona on 3dsMax I have a thousand identical teapots, do I save any memory what so ever at render time if:

A. all teapots are regular max instances? (as opposed to copies)

B. all teapots are proxy? (all as instances, linking the same .cgeo-file)

C. all teapots generated with forest pack?

11

[Max] I need help! / Exposure Value (EV) and Camera UI

« on: 2017-10-20, 11:30:25 »

Hello!

I'm fairly new to Corona, and tried my best to search for information about how the exposure control under the camera tab in render settings is supposed to work. But I didn't find much.

We're running 1.7 DailyBuild Sep 20 2017 in the studio.

And I've found that when using "simple exposure" the term EV is used incorrectly. It doesn't at all correlate to actual EV-values that have been used by photographers for decades. For example. EV 8 should give the same result as 1/4 at f/8 at ISO 100. But EV 8 is way brighter. Is this a bug, or is it a Corona native way of adjusting exposure were higher numbers makes it brighter and lower makes it darker?

I assume a lot of beginners or people with low level of knowledge about cameras and exposure would like it to work that way. But you cannot write EV next to the value in that case. That would be like writing ISO or F-stop and not having it behave like ISO or F-stop. It's wrong.

My suggestion, if this isn't a bug in the version I'm running, is that you don't write "Exposure (EV)" under simple exposure, instead brightness, and make another value for actual EV values. Or just write "exposure", not EV. And maybe move EV to photgraphic settings?

As a photographer I also find it strange that White balance is only in Kelvin, and that there is no green-magenta shift. Or that you can't color pick from the framebuffer. But that's just me.

Also UI-wise there is some tidying that could be done. Some settings under the camera tab are global, no matter if you flip between simple exposure and basic photographic. But they are layed out as if the belong to either simple or photographic.


This is nit-picky I know, and I hope I don't come off as hysterical ;)

Kind regards!