LightMix Corona 1.5

[julecocq]

Hi Corona Community,

I'm facing a problem with the new awesome LightMix feature.

1- In a scene, I saved out a few different light situations / light mix, 4 actually, but each output (exr) were looking the same. Like if I didn't play with anything... Is there something special to do I didn't get ?

2- Is there a way to load a render, to play again with lights ? I didn't find a way to reopen Max, load an exr for example, and then, create new light situation / light mix, without re-rendering the scene.

Thank you guys !

[julecocq]

I guess to do this, we should use the .cexr format instead of .exr ?

If yes, Max is giving me a pop up, saying Error Creating File Output  (not popping up in .exr)

:(

[maru]

Hi, sorry for the delay. Did you manage to solve your problems somehow?

1. Did you save the light mix element? Or just the beauty? (output) Remember that what you see in the VFB when playing with lightmix is the lightmix element.

2. Yes, Corona EXR format should work here. Does it?

[popeye72]

Hi,
I downloaded the trial of Corona 1.5 for 3DS Max 2017 last monday. The lightmixer is an incredible tool. Tested it with some of my recent Mental Ray projects and was flashed by it. The only problem is, like described above, I dont know how I can save these results (besides saving the final result as tif or jpg), so that I can continue to work on the light mixing later on, even if 3ds max was already shutdown since the last rendering was done. When I save it as Corona EXR there is only one layer included. It would be great to have a tutorial which shows the workflow how to save these light elements and the lightmixer layer for later editing in 3ds Max or Photoshop and in which format it must be saved.

Thx in advance for any tips!

Popeye

[TomG]

Hi popeye72!

A tutorial on using the results in post rather than in the VFB is definitely on the cards - most likely I will use Fusion for that, to showcase animation possibilities (Fusion is free, so all users can follow along in the tool if they like, or adapt the workflow to their tool of choice.)

From what I recall from my last tests, I used Save All to EXR, to get separate EXRs for each LightSelect, and the notes I left myself (a bit cryptic til I revisit and turn into a video tutorial but might give you a start) were:

Open in Fusion
Use the Format to extract the channel we want
Connect via a Merge, which is Add automatically. Turn Alpha Gain to 0. Use Blend to control strength
Merge the merge with the next source

For Color Corrector node, enable Pre Divide Post Multiply under Options
Use RGB Gain to adjust the brightness

[julecocq]

Hi There,

Thx for your replies guys !

I think the main question is about, how to be able to use this feature, as Maxwell does, with MXI files. Means being able to tweak lights, a long time / some time after a project is done for example. Not doing anything in PS or Fusion or whatever post-production package. But to make it within Max and Corona.

Thx !

[TomG]

Not currently possible, but noted in this post was that a standalone denoise/postprocess/lightmix application is being developed for that kind of use:
https://forum.corona-renderer.com/index.php/topic,13422.msg86598.html#msg86598

[julecocq]

1- ok so the solution to tweak lights, after rendering, and after turning off Max, is only possible in post-production ?
2- Then, why being able to save light presets / corona configuration ? it is just for instant tweaking ?

[julecocq]

We are currently working on a standalone denoising/postprocessing/lightmix application, so stay tuned for 1.6 release

Would be awesome to have something maxwell like :)

good luck guys !

[TomG]

Saving light presets is handy for rendering the same scene from different cameras - you can then instantly load the light set up to duplicate it exactly for any renders for that scene. Saving VFB presets is more general, you can load those in to any render (LightMix is scene dependent, while VFB post-process is not), but yes, only while that render is present in the VFB.

For now, yes, the only way to tweak an image after shutting down Max would be to re-render it, but that is what the planned future development is intended to look into, to give alternatives to that :)

[julecocq]

super, looking forward guys :)

[popeye72]

ok thx for that information. being able to tweak inside max without having torerender after shutdwon would be realy great.
Will also test saving the rendered lights layers in one big exr file, thx for that detailed information!

[popeye72]

Hi TomG! thx for your informations. I have a question:

From what I recall from my last tests, I used Save All to EXR, to get separate EXRs for each LightSelect, and the notes I left myself ....

Save all but on which layer doyou apply that? For the Lightmix effect, or in the common render tab? Wasnt succesfull yet. I activated it for each light select and in the common render tab, allways getting only one layer

[TomG]

Hi popeye!

For the Save All, for my test I just did that from the VFB, chose Open EXR format, then in the dialog for Save All I made sure "Automatically Add/Remove Render Elements From Render Dialog" was checked. I then get one EXR for each LightSelect (and any other render elements). Hope this helps!