LUT support

[martinsik]

We are considering adding support of LUTs into Corona VFB.
There are however many different ways this could be implemented, I am therefore starting this topic, so you can share your visions :)

Some of the questions we would like to answer in this "survey" are:
1)What LUT file formats you usually use?
2)Do you apply LUT as first step or last step in post process? (Some softwares allow both)
3)Should we support both linear and log LUT files?

[dubcat]

1) I prefer .cube, but I know some people use .3dl.
Fusion use .3dl as default.

2) I prefer to have the LUT before "White Balance", like Octane. That way you can use the "White Balance" color picker after the LUT has been applied. Right now I white balance all my LUTs before I use them.

3) The LUTs you create in Photoshop/Fusion/3DLutCreator are for 16bit sRGB. But like 80% of what you find online are made for Log cameras. Right now I extract the "master curve" from the Log LUTs, that way I can use them as normal in 16bit sRGB.

EDIT:
Please add a "White Balance" color picker to the VFB and opacity slider for the LUT.

[lmikkelb]

1) usually I use 3dl.

2) usually apply it at the end, both could be an option. Although it whould be nice to be able to controll the LUT intensity.

3) If u are thinking about adding support for different collorspaces, what about linear, sRGB, rec709 and log.

Are u planing on having some luts delivered with the engine?

[lmikkelb]

EDIT:
Please add a "White Balance" color picker to the VFB and opacity slider for the LUT.

Totally agree, A fast way to whitebalance and a focus picker has to be more important than LUT support. I have only tried the lut solution directly on the render in Octane, and thats a really nice feature, could it be
possible to have something like lift, gamma and gain before LUT support? That way we have more controll over the contrast (the saturation is a nice feature). Then at the end maybe apply LUTs, just to test different color variations on the image. We also need a button to turn things off, in a quick an fast way, an hiding things in the post tab. leaving only exposure and maybe whitebalance, ready for compositing work, its to easy to render something and then later realise you forgot to reset one of the sliders, help me not to make mistakes:D Sorry maybe I went a bit off the LUTs topic. 
Anyway the glare, glow and vignetting, works and looks amazing!

[Lwmotion]

Lut support sounds great but for more flexibility wouldn't the ability to export renders in a flat/log color profile be more flexible so we can grade the cg work in Photoshop, After Effects, Nuke, Davinci Resolve, etc.? Do we really need to do this much work in the VFB? Right now the best tool I've found for grading cg work is ArionFX but they only have a plugin for Photoshop.

[GabaCGStudio]

i want multi LUT support (.cube and .3dl) with sliders :]

[scionik]

I prefer *.3dl

[Pixel Folks]

Both with sliders would be great! that with flare and glare would be really nice

[antanas]

Some sort of window\selector for quick cycling lut's directly from vfb like the one currently present in render setting would most probably be quite useful. Otherwise Lut support seems to be great ! Tried it today for the first time - somehow missed it before because of all the lighmixer induced excitement + had nothing to add to the discussion cause I'm pretty clueless in regard of working with lut's ))