Best Corona Workflow for a new user (coming from VRay) [update : path conflicts]

[pixelab]

Hello,

I'm testing Corona with a 1 month fairSaaS on a commercial projet this month. I have some question on the best workflow to adopt. I come from VRay (and still using it), usually we do the renders in 4800 x 3200 resolution in backburner, often with DR.

My questions :

- I've not seen any mention of LWF here, I guess Corona is 100% based on LWF ? Gamma setup of MAX is 2.2/2.2, is that right ?

Ok, just read that Corona is full 2.2, that answers my question

- I have an interior scene with multiple cams. Do I have to "find" the right exposure + glow + Colormapping (+ eventuallyLUT) and then copy it to CameraMods on all my cams ? is there a way to copy paste the values frme the VFB to the cmaera mods (cumbersome if I have 10+ cams in a scene) Maybe a CoronaCameraMod lister where I can batch edit ?

- If I want to HDR the scene, is there a way to change the gamma of the HDR like we use to do in VRay (no Corona HDR loader? CoronaOutput doesn't have a gamma slider.) Ok if I colorcorrect with a map the HDR and put everything in the env. slot or I will lose the HDR property of the map ?

Since VRayHDRi should works, that solves this for me

- Is there a way to "unbake" the Glow/Glare in the beauty pass (I have found the glow/glare element, but dunno how to have the beauty without the glow/glare)

I'll try to batch render drafts for the clients but so far I'm having some bugs with the render elements... wil post other issues along with the progress of the project.

Thx everyone !

[maru]

Hello,

Hi!

My questions :

- I've not seen any mention of LWF here, I guess Corona is 100% based on LWF ? Gamma setup of MAX is 2.2/2.2, is that right ?

Ok, just read that Corona is full 2.2, that answers my question

Yes, no need to change any gamma/LWF settings. See: https://coronarenderer.freshdesk.com/support/solutions/articles/5000515647-how-to-configure-gamma-

- I have an interior scene with multiple cams. Do I have to "find" the right exposure + glow + Colormapping (+ eventuallyLUT) and then copy it to CameraMods on all my cams ? is there a way to copy paste the values frme the VFB to the cmaera mods (cumbersome if I have 10+ cams in a scene) Maybe a CoronaCameraMod lister where I can batch edit ?

You currently have 3 ways of setting exposure:
1. through CoronaCameraMod
2. through 3ds Max physical camera
3. through render setup > camera

They are prioritized like I listed them. CameraMod has the highest priority - its settings will be used even if you use the physical camera or render settings. The lower priority settings will be ignored. This is currently sometimes cumbersome, but it is really hard to find any better solution. We are however planning to find it in the future. :)

- If I want to HDR the scene, is there a way to change the gamma of the HDR like we use to do in VRay (no Corona HDR loader? CoronaOutput doesn't have a gamma slider.) Ok if I colorcorrect with a map the HDR and put everything in the env. slot or I will lose the HDR property of the map ?

Since VRayHDRi should works, that solves this for me

Do not use VrayHDRI. It is likely to cause some unexpected problems (flickering, crashes, etc), which will be then hard to diagnose. The 3ds Max "load bitmap" dialogue and the native color correction node offer exactly the same gamma correction capabilities as the VrayHDRI.

- Is there a way to "unbake" the Glow/Glare in the beauty pass (I have found the glow/glare element, but dunno how to have the beauty without the glow/glare)

You can use a combo of CShading_BloomGlare and CShading_Beauty elements. The CShading_Beauty can have denoising and bloom/glare toggled on/off.

I'll try to batch render drafts for the clients but so far I'm having some bugs with the render elements... wil post other issues along with the progress of the project.

Sure, we will appreciate any bug reports either on the forum, or on our bug tracker: https://corona-renderer.com/bugs/

You can also always contact us about any issues you are experiencing, or advices, using this form: https://coronarenderer.freshdesk.com/support/tickets/new

[pixelab]

You currently have 3 ways of setting exposure:
1. through CoronaCameraMod
2. through 3ds Max physical camera
3. through render setup > camera

They are prioritized like I listed them. CameraMod has the highest priority - its settings will be used even if you use the physical camera or render settings. The lower priority settings will be ignored. This is currently sometimes cumbersome, but it is really hard to find any better solution. We are however planning to find it in the future. :)

Actualy it's clearer now with your explanation. I'll stick to the CameraMod workflow, and find the values by deactivating the override and playing with the numbers in the VFB. I can then copy those numbers in the override, and copy the mod to other cameras, and infe tune ther if necessary.

Do not use VrayHDRI. It is likely to cause some unexpected problems (flickering, crashes, etc), which will be then hard to diagnose. The 3ds Max "load bitmap" dialogue and the native color correction node offer exactly the same gamma correction capabilities as the VrayHDRI.

Ok ! It would be nice to have a Coronoa HDR loader som time in the future like asked in other threads. I understand that you are probably asked a lot of features of VRay, but MAX bitmap loader is really counterintuitive (output "amount" for multiplier, rotation on a 0/1 scale, etc., no gamma in the loader, etc.)

Thanks a lot for the other infos and your kind answer !

2 other questions have popped meanwhile :

- When rendering, and if a region is active, pass number is going up very fast (I guess because it indicates the sampling of the region) But if all region are removed, the number doesn't seem to come back to what it was. Issue is then that the render might end too soon (reach the max passes too soon) .. or maybe I'm reading wrong ;)

- Why the DR slaves are showing pass number really low, or even "initial pass" when the main render (master) is already at 100 passes ?

That being said, Corona is a really nice engine to play with, ofc it has a lot of similarities with VRay, but you managed to pinpoint some light "feeling" better, and migrating (or co-using) from/ with VRay is almost painless !

[pixelab]

Ok, I stumbled on a new problem, mainly about file saving.

My worflow is making 3/4 cameras in a scene, each with his own resolution (landcape or portrait) and its CameraCameraMod. I send the renders to ou local farm, with Batch Render to Backbruner. Each cam receives an output path to avoid conflicts.

Problem is : Render elements don't take those path into account, and just use the regular Max path which is always the same.

A workaround should be to include frame number into the filename (like VRay does ... I know I know)

Or I'm doing something wrong ? What's the worflow with multiple cams in a scene to be sent overnight in batch on a farm, and to receive each beauty coming along with his elements ?

[johan belmans]

Hi there

We have the same sort of scene setup, multiple camera's each with therir specific camera mod in one scene.
We send them straight to backburner and render them as EXR's. But I presume you are doing this to. All the render elements are saved within your EXR file.
So you avoid your problem with the regular Max path.

cheers

Johan

[pixelab]

We send them straight to backburner and render them as EXR's. But I presume you are doing this to. All the render elements are saved within your EXR file.
So you avoid your problem with the regular Max path.

Thanks Belly for you answer! Actually, I moved to corona on small projects especially to avoid EXR workflow. EXR is really nice, but once in photoshop it's a nightmare (slow, unstable, etc.) The idea is to have 95% of the post done by Corona, but still have the masks to do quick modifications afterwards.

Meanwhile, I remembered what I was looking for. You have to empty the path in render elements. It's quite obscure and honestly, file management/ saving could be improved in Corona (and VRay has his problem too)

[johan belmans]

FYI: file saving is handled by Max :-(

In our case we do the post processing in Corona. We render as EXR once they are rendered, we load them back in the corona framebuffer and do most of post processing there. Once done, we save a config file of the settings per camera (for later re-use). Save the file and do some small corrections in Photoshop and soon in Photo Affinity.

cheers

[maru]

It is almost certain that the problem with elements losing their paths is a 3ds Max thing. If you believe it's Corona - we need proof (e.g. that it works flawlessly with other renderers).
One "solution" to this is removing all render elements from the list, and then re-adding them back. It sometimes fixes the problem completely. It is also possible to update render element paths using the Asset Tracker (Shift+T).

[pixelab]

In our case we do the post processing in Corona. We render as EXR once they are rendered, we load them back in the corona framebuffer and do most of post processing there. Once done, we save a config file of the settings per camera (for later re-use). Save the file and do some small corrections in Photoshop and soon in Photo Affinity.

cheers

Thanks for your workflow explanation !

How does the post work in Corona when you reload an EXR ? Are you able to change the exposure, bloom/glare, LUt (I don't use it but might try) afterwards ? And eventually lightmix ?

It is almost certain that the problem with elements losing their paths is a 3ds Max thing. If you believe it's Corona - we need proof (e.g. that it works flawlessly with other renderers).
One "solution" to this is removing all render elements from the list, and then re-adding them back. It sometimes fixes the problem completely. It is also possible to update render element paths using the Asset Tracker (Shift+T).

Thanks for the explanation !

VRay ignores the element path, empty or not. but elements are saved by VRay and not 3dmax. As long as corona trusts 3dsmax for saving files, we're stuck with max bugs (those are never solved) :)

Looks like emptying the path via the Asset tracking might be a quick workaround (I guess "strip path" is the way to go)

[maru]

...as long as corona trusts 3dsmax for saving files...

Are you kidding? ;)

[johan belmans]

Thanks for your workflow explanation !
How does the post work in Corona when you reload an EXR ? Are you able to change the exposure, bloom/glare, LUt (I don't use it but might try) afterwards ? And eventually lightmix ?

I based this workflow on Dubcat's post see reply #10 https://forum.corona-renderer.com/index.php?topic=13341.0.
You can change all the settings in the Post Tab (except of Denoising). Normally with the release of 1.6 there will be a stand alone app for Post processing and Denoising. I hope then file saving will be handeld by Corona.

[pixelab]

...as long as corona trusts 3dsmax for saving files...

Are you kidding? ;)

I don't get it ? I hope I don't sound arrogant / unpleasant but so far, saving elements with Corona has been a mess for me. Naming, randomly overwriting, blank elements saved.

Corona should really benefit from a dedicated saving function, to allow saving the elements altogether without the risky busniess of trusting 3dsmax. Having the frame number appended to the filename would also be a big plus, allowing multiple workarounds, and a lots of worflow with animated parameters to match different cameras. And also being able to use batch rendering efficiently.

For example, I removed the path in the Asset tracking, and now no element is saved... I'm a bit lost...

Also, the "visible in masks" is a nice idea but refraction affecting the mask is way more useful (to have RGB superimposed masks... again like in VRay ;) )

Thanks for your workflow explanation !
How does the post work in Corona when you reload an EXR ? Are you able to change the exposure, bloom/glare, LUt (I don't use it but might try) afterwards ? And eventually lightmix ?

I based this workflow on Dubcat's post see reply #10 https://forum.corona-renderer.com/index.php?topic=13341.0.
You can change all the settings in the Post Tab (except of Denoising). Normally with the release of 1.6 there will be a stand alone app for Post processing and Denoising. I hope then file saving will be handeld by Corona.

Thanks for pointing me directly to the source !

So the workflow is basically to render the image to get the image in the buffer ??? that's some far fetch workaround for a missing "open" function :)

I guess I'll wait for a standalone (or a simple "open file" function in the VFB) because this workflow is unusable in a team /production environnement.

Eagerly waiting the futures improvements of 1.6 ! :p

[johan belmans]

Thanks for pointing me directly to the source !

So the workflow is basically to render the image to get the image in the buffer ??? that's some far fetch workaround for a missing "open" function :)

I guess I'll wait for a standalone (or a simple "open file" function in the VFB) because this workflow is unusable in a team /production environnement.

Eagerly waiting the futures improvements of 1.6 ! :p

The workflow I described is not "the workflow" you have to follow or is told by Corona you have to do. We are a small studio and for us this pipeline is excellent for stills.
I made a Max template file so I just have to change the render in the material editor, fill in the correct resolution of the image, push render (just one pass) and play around with the post production settings.
Whenever we have to rerender an existing render due to small changes, we rerender the image with the saved config file and can go straight to Photoshop for the last small adjustments.
But ofcourse if you just have to open the file in an app it wil be quicker. But for now I am staisfied.

[pixelab]

The workflow I described is not "the workflow" you have to follow or is told by Corona you have to do. We are a small studio and for us this pipeline is excellent for stills.
I made a Max template file so I just have to change the render in the material editor, fill in the correct resolution of the image, push render (just one pass) and play around with the post production settings.
Whenever we have to rerender an existing render due to small changes, we rerender the image with the saved config file and can go straight to Photoshop for the last small adjustments.
But ofcourse if you just have to open the file in an app it wil be quicker. But for now I am staisfied.

You might be surprised how slow photoshop + ArionFX is for opening, post processing, and saving an image from a RAW. I did it multiple times and it bacame a tedious task.

I'll try your workflow, mostly because I find Corona really fast and pleasant to use for this task. OFC, a simpler way to do it with Corona would be a big plus.

thanks for your insight :)

[johan belmans]

You might be surprised how slow photoshop + ArionFX is for opening, post processing, and saving an image from a RAW. I did it multiple times and it bacame a tedious task.

I'll try your workflow, mostly because I find Corona really fast and pleasant to use for this task. OFC, a simpler way to do it with Corona would be a big plus.

thanks for your insight :)

I am familiar with Arion FX :-)
Oh, if you save your render from the framebuffer, use Tiff 16 bit with no alpha channel as an extension. If you would use EXR or PNG (8bit) it will take you almost 5 minutes for a 4K render, where Tiff will take 20 sec.

And you are welcome here https://forum.corona-renderer.com/index.php/topic,14548.0.html