Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] Bug Reporting => Topic started by: Robwan on 2021-06-15, 23:18:14

Title: Very first render upon opening a file is different to all subsequent renders
Post by: Robwan on 2021-06-15, 23:18:14

Hi everyone,

I Open the max file > Hit render (interactive or normal doesn't matter) > Image renders.

Stop render > Hit render again > image renders darker. Not overall exposure but looks different in general with certain things looking darker or more shadows being applied. One other thing I noticed is that a mirror in the scene is still reflecting the light version of an object which is now dark.

From here on it just renders like this, until I close the file, reopen and hit render for the first time only. It's largely an issue because I'm sending to Deadline. Once I send to deadline it reopens the file and therefore renders lighter again.

Unfortunately I can't share the file but wondered whether anyone has any ideas. It's very bizarre and I've never encounted anything like it in all my years of working with max+corona.

It's a simple interior scene
Only corona sun and sky plus a few internal corona lights
I'm a vanilla user, I don't change any render settings, have very simple setups.
No Xrefs
Corona 6 hotfix 1
max 2021

Any help is hugely appreciated.

Cheers

Title: Re: Very first render upon opening a file is different to all subsequent renders
Post by: TomG on 2021-06-15, 23:43:02

It would be good to see what you mean - either the saved images, and / or a video showcasing it (which can be sent via private uploader rather than posted publicly - same for the file itself which could be useful too, but assuming that the file absolutely, cannot be shared, a video of what is happening could be useful). This also leads to the other question - does it only happen in this one scene? Otherwise, you could make a scene that demonstrates the problem and send it on over.

Title: Re: Very first render upon opening a file is different to all subsequent renders
Post by: maru on 2021-06-16, 17:44:44

Are you getting any error messages from Corona whatsoever? This sounds like a gamma issue. Please see: https://coronarenderer.freshdesk.com/support/solutions/articles/5000515647-how-to-configure-gamma-for-rendering-

It could be something very different, but as Tom said, we would need more info - ideally the images showing the issue, which exact Corona version this is, Max version, and any other details you can provide.

Title: Re: Very first render upon opening a file is different to all subsequent renders
Post by: Robwan on 2021-06-16, 22:08:25

Hi Maru, TomG,

Thanks for the replies. yea unfortunately I cant really share anything, But I am curious what it is so when I get a moment I will try to simplify the scene or edit it so I can show something possibly.

I don't get any errors and I'm sure my gamma settings are correct but I'll double check.

Title: Re: Very first render upon opening a file is different to all subsequent renders
Post by: TomG on 2021-06-16, 22:16:00

I don't think it is what is happening here, but the one time I've confused myself is in a scene with LightMix, where I am looking at the Beauty rather than the LightMix or vice versa (but that shouldn't change by itself just by hitting render again, though, which is why I don't think this is what's happening here - still, no harm in ruling out possibilities!)