V-Ray LUTs Explorer

[^Lele^]

Little script one points at a root folder which contains .CUBE LUT files, and then can browse those with a realtime feedback in the VFB.
It also allows to export a set of RGBA images, one per LUT, in any of the VFB-Supported formats (it includes only two extensions in the file save, for simplicity's sake, but one can override as wished.)for further post-process.
Note that saving Exr images will NOT save the tone mapping with them, use a LDR format like the ones suggested, or save the EXR and move the LUT application to post.








and a small video on its basic usage for the early version (mind the shift and control keys!).
V-Ray LUTs Explorer Intro Video.zip

No support offered, no requests accepted.
Feel free, however, to expand on the code as you see fit.

LUTsExplorer_008.zip

EDIT: V0.03 offers auto-detection of LOG/LIN LUT types from the filename (there is no consistent use of metadata in the cube files to that purpose).
It can always be overridden, of course, but comes in handy to save out wedges.
EDIT: V 0.05 fixes a potentially nasty bug with preset saving.
EDIT: V 0.06 adds tooltips to all the UI controls.
EDIT: V 0.07 adds back in the ability to save variants. As a temporary workaround fix to the focus stealing, have every VFB accessory panel (Color correction, history, lens effects and so on) CLOSED when running the script.
EDIT: V 0.08 has a temp fix for the focus stealing, which consists of the script hiding the side panels before (auto) applying a LUT. Drawback: it currently doesn't restore the panels status, so you'll have to unhide them manually.

[M.Max]

Thanks Lele ! it is really handy tool

[mitviz]

simply awesome!

[Sbrusse]

oh ho, this seems to be the tool we where all waiting for when the LUT hype came through few months ago!
Thanks Lele, seems awesome!

[jstrob]

No support offered, no requests accepted.

Do you at least accept praise!

Thanks Lele! I just discovered LUT with Fstorm and now it seems I can play with them as easily in V-Ray!

Anyone knows where I could get a nice set of LUT to play with?

[mitviz]

Deluts has some nice ones

[jstrob]

I just noticed Fstorm installed a batch of 46 Lut (.cube) in this directory: C:\Program Files\Autodesk\3ds Max 2017\LUT

It's also quite easy to generate our own LUT file in photoshop: http://www.premiumbeat.com/blog/how-...-in-photoshop/

But what's the purpose of lut files if we create them ourselves?

I found some free ones here:
https://luts.iwltbap.com/
http://www.smallhd.com/community/movie-looks-download

[Sbrusse]

LUTs are look up tables this mezns that it shift a certain color into another.
As easy as it seems, it's only a file that condense a color grading that could have been done with whatever post production tool (in different steps).
So yes, you can build them youself of course but those who already exist uses the knowledge of people how are usually professional graders.
Keep in mind that as those are just chats to shift colors, they have been created to work on a certain type of footage in the first place or to give a certain mood to a film etc.
That's why one LUT will not work for all your different shots and why we want to be able to scroll through a bunch to give a different look than the one we have out of our raw render because a) we are bot constrain to a specific look and b) because the same lut wont give the same result depending on the raw footage.

LUTs is a old technique that is commonly used in film and advertising productions but they seems to get pretty trendy those days build in the render frame buffers.

I'm more interested in getting a proper bloom and glare like FStorm or Octane one straight in Vray, that would make a huge difference as it's not that easy to the those properly done in comp (at least not with AFX)

[jstrob]

Yes and the LUT can give the intended look only if it came from the same kind of source the LUT was using when it was created, so that's why many LUTs will just look like shit when just playing with them randomly. So we need to find LUT that were created to work on linear image I guess.

I asked in the wishlist section to add a weight for the LUT in the VFB. Another useful thing could be to be able to layer the LUT. I know it sound against what LUT are made for but it could add more variations. We then completely loose the expertise that were put in those LUT in the first place when layering them, but it's more a way to play rapidly with many random variation of color grading. Creating new variation by varying each LUT weight and layering them. the more we have variation and the more we can adjust them the fastest we can find the right recipe. It's like cooking when we play with different spices.

It is a old technique that I heard about since probably 20 years but I never really knew what it was exactly. Now I'm so happy to know! In fact it's just a preset of color correction filters.

I played with the glare and bloom in V-Ray and also in Fstorm this week. Normally I would always do that in comp cause it's way too slow in V-Ray. In comp I could get decent result pretty fast. But in Fstorm it's just photoreal and real time too. It's also better than what I usually get in comp. And the good thing is that you get instant feedback so you can adjust your rendering settings to get the perfect glow really fast. We really need this in V-Ray too! Sounds like a gadget that serious production will not use cause they do that in comp. But I think it's more than that. It's a tool that will allow us at the 3D step to find the right render, shader, lighting settings to get the perfect photoreal look along with LUT hand in hand. Cause LUT is also the same kind of tool that allow us to prepare our render outputs more perfectly and rapidly for the compositing step.

[Sbrusse]

I completely agree,
I'd love a layered LUT interface, just wish that could be true one day.

[mitviz]

it would be a good idea to have an opacity slider because alot of the luts can only be used at a fraction of their strengths on rendered images so when you actually bring a lut into vray its either that lut is modified already to a weaker value somehow, easiest way now is in photoshop because using them as is in vray doesnt really give the results i am looking for.

[^Lele^]

it would be a good idea to have an opacity slider because alot of the luts can only be used at a fraction of their strengths on rendered images so when you actually bring a lut into vray its either that lut is modified already to a weaker value somehow, easiest way now is in photoshop because using them as is in vray doesnt really give the results i am looking for.

no can do.
save wedges, go PS.

[Sbrusse]

Lele, the whole purpose of the FStorm / Octane (few months ago) etc is to skip the step of a post production tool, either PS or Nuke or afx or any other.
Those artists (me included) want to be able to have a final deliverable product to the client straight out of the VFB.
I know it doesn't make sense for those who are used to a bigger pipeline where you need to export as linear and do a hundred of things after the 3D step, but it's not the case for a lot of people out there that works on any other kind of work than big productions.

[^Lele^]

Those artists (me included) want to be able to have a final deliverable product to the client straight out of the VFB.

Besides the fact that i can't fathom why you're advocating delivery of NEGATIVES (Or Polaroid prints) to your client, and disregard the DEVELOPMENT (Or are unhappy at the Polaroid's one) as if it was a dirty, or expensive, thing (Fusion is free for commercial use.), if i had a penny for each of my wishes, i'd be a millionaire today.

The truth of the matter is that I can't do it.
You want, you have the code, and permission (encouragement!) to edit it.
Will, means, and allowance: get editing!

[Sbrusse]

I haven't said it's dirty or expensive, I know some tools are free and we have bought few of them.
I'm just saying I like to get all my groceries from the same super market, it take me the hassle away of taking my car to go to 5 different shops.
Beside being easier, it brings me home earlier to see my family.

The whole purpose of that talk as I said (and I can dig up the thread of octane if you can't remember) is that we want to have that integrated in the VFB.
We are not coders, we are artists, and we are here on this forum to try to push the development stage of the software into the direction we thinks it would serve us best.
I know you can code though but you're also a artists so you are kind of in between and have two hats on your head, that's great but if you say you can't with this tool, well this shows again why we would need that integrated straight into the VFB. Or do you imply no one in Chaos Group could code a blended layered LUT CC in the VFB at all?

But hey, if the only response from CG to wishes is : "do it yourself" well then I guess I won't spend so much time trying to push Vray forward (IMO) anymore.