What if that same person asks you to change your geometry or move something, you’re also fucked…To take creative freedom away because of “what if’s” is counter intuitive to the creative process IMO. I can tell you for a fact, if I was still working in the print industry I’d be testing and using LUT’s regardless of if they were baked in. The retouchers wouldn’t care, they’d just do what they wanted to the final image anyway. I could also save out the original and baked version, then they could blend in the amount in post.
When did CGI Artists become CGI technicians :S
But my argument isn’t against using LUT’s - my point is we can ALREADY load them into the vfb, without having to bake them into the final image.
Hahaha I totally misread what you posted, my bad.
Any chance you could email me a link to a 3dsmax 2014 build of that nightly if you have time? I’m not on nightlies 
I do know a wee bit of both physics and visual perception, but i fail to see where the color theory above has any visual impact, Gavin: show me a control image, one with and one without invisible colors (Like IR contamination, or UV spectrum bits), on a standard RGB display device, then we can maybe confront what the variance is, mathematically, and with a control group of humans, study the perceptual difference and likeable-ness of the three.
For right now, in plain RGB, without UV-Ray (this year’s april’s fool, btw), the matching is (and has been for a while) good enough for technical professionals to rely on when moving towards the physical realm (or in and out of it, with the scanned materials).
There’s a serious amount of help coming from Post, but that is also where ALL of the color conversion away from LWF takes place, and where a non-linear human or camera response curve can be countered efficiently to normal conditions first, and to the desired tonal range then.
Is it perfect a method? Of course not: it’s much more discrete and limited, compared to Nature.
Is it a dependable assumption to make in most situations? Yes it is. Compared to Nature (there is quite the literature on the subject: rendering approaches weren’t chosen on a whim.).
Photons do not change their energy based on your perception of them, rather, they have a precise amount of energy based on their wavelength, and it’s the atomical structure of materials getting excited by the different wavelengths and emitting a photon back of just the right one which we call colour (and Albedo).
That is what a renderer should calculate, within the bounds of the visible spectrum (how many channels ought to represent a visible spectrum well enough for human consumption is quite debatable, outside of a few specific cases. We also dither quite a lot, perceptually.).
If a renderer had to (or pretended to.) cater for the variance in visual perception in humans, wow, that would make for fun times.
This wasn’t a debate on color perception, anyways.
This was a debate which was set on a course driven by two running rumors:
A) octane is doing it better in terms of light transport models and physical accuracy, and
B) VRay will get close enough if we add those “corrective” camera response curves to make it behave like Octane.
I rebated with a set of Octane renders which aren’t in LWF, or which are in the CM section, but then are clipped, in response to point A), and renders which ought to be white by the standards of not just VRay, but everyone else which isn’t a niche product (rMan, Arnold, iRay, Corona), and instead show all sorts of (perhaps correct?) non-user initiated, nor user-changeable, skews and deviations from the norm (namely, the light intensity and colour) for point B)
All I care for is objective, and measurable data.
Even speculars can be measured against each other.
“Pretty” isn’t something that can be measured, but the lobe to tail ratio and the intensities can, even on very complex scenes.
Even with the best match Grant could get, the specular models look quite different in a number of places, and matching two different models may well be impossible.
Once we establish that everyone else is doing the expectable, and what’s been proven right enough to fool millions of perceptual machines in humans over many a year, we can still CHOOSE to go with the odd one doing things its way.
Just my maths and historical results will not change despite what anyone else chooses.
I was never in the debate from stopping the use of Octane, i entered it to set a few records straight.
We can take the nitty gritty of what’s supposed to be in a render engine core these days to a private place and debate it to exhaustion, but i think i demonstrated the two points i wanted to make, in here, with simple enough, and reproducible enough, data.
I’d love to be treated in kind, rather than with hypoteticals, so the debate can stay on course.
And most of all, i still see no case for the camera curves being provided by ChaosGroup (it’s a 1d lut in plain text format. vray has a LUT input already. Get converting, says I.) nor that those could or should be used with HDR renders (the curves are in the 0-1 range. so clipping may be a feature, not a bug, also in Octane.).
But everyone will get them anyways, very likely.
With good peace of the people asking for fewer controls throughout the VRay UI, and a streamlined workflow.
Baking colormappings in LDR images doesn’t sound like much of a workflow to *me*, so no, *I* shall stay on record flatly stating they’re not going to be of any help, but rather hindrance.
I guess time will prove me wrong once again: it wouldn’t be the first time, it won’t be the last.
Regardless, my renders will never be clipped to 1.0.
As for hat VRay needs to match competitors after all the testing, i’d say it would have to add a few useless loops and slow down a wee bit, lest those amazing articles on hundreds of hours of rendering per VFX frame turn out way shorter. 
Jokes aside, Chaos is pursuing a few avenues which are quite interesting.
Nightly builds are provided to the beta group, under NDA.
Feel free to apply!
P.s.: i did a short test too. Can anyone tell me how to enable importance sampling for IBL lighting in Octane for Max? I don’t seem to be able to have it work (there’s no dome light object, and no option in the bitmap loader when the HDR is used as a background. so i get the results you see below. Manuals are quite opaque, and i’d have thought something like that would be quite visible without trawling forums…). In the renders below the background HDRI providing light is a render of a VRay sky, and it matches for position and intensity. Octane’s simply missing the very intense and very small sun disk. Notice that also means a (potentially a LOT) faster convergence, due to the fewer high-intensity samples bouncing around, but until i get it to correctly sample the Bg I’ll never know.
All renders achieved the same sampling level (1024RPP) and were rendered on a GTX 980.
P.P.S.: the tests i am doing are on gray shaders not because i haven’t found colours yet, but because they make retrieving what is happening simpler to read (R,G, and B become V, 0-255 ranges are 0-1, so the maths simplifies.), and further shows precisely the lighting colour (times the intensity of the shader’s diffuse, 0.75 in the renders above) when a surface is hit (ie. the picked color is the light’s not the shader’s.). If the basics are set right (ie. LWF) then i can move to more complex scene and shading models conversion. Doing it backwards would make the job of figuring things out very complex indeed.
I’m just wondering : When does anyone has asked to BAKE the LUT profile into the render?
I was thinking we where asking for a possibility to have a “list of presets”.
Now, that in that “list of presents” there are some film response curves or your own home made curves or other you could buy on turbosquid, whatever, it’s all the same, we just want the possibility to switch through them and use a LUT based on a present, and not having to load them by hand.
As I said in my previous message, I would still be rendering linear at save out linear. It’s just for workflow purposes that having a list of preset would make it way easier.
For now, if you use any of the tools already present in the VFB (exposure, highlight burn, contrast, WB, hue/sat, curves, whatever) it all bake it in the image if you are not careful enough to uncheck them before saving (so you are already breaking LWF there… and I also demonstrate few message before that the curves are broken in the VFB.)
BUT, LUT are not baked into the saved image…
So why are we talking about baking any of that LUT info to the image and break LWF in the first place?
Now, having that data of film response curve converted to LUTs, well, it would be really helpfull if someone that has the skills to convert them could do it, I know I don’t have them, and it seemed Grant didn’t either, and that’s just why I (at least, maybe Grant as well but I don’t want to talk in anybody else name) would really appreciate if Vlado or any other person from CG could convert them to LUT.
Now, that anyone drop that data into the folder with all the presets that could be available for the VFB, that’s his internal workflow pipeline and personal preference.
I just don’t get why it’s so unbelievable to have a list of presets for LUT…
Stan
You write this so elegantly, but i still read it as “more chances for messy people to get more things more wrong.”.
And it’d be all good, if the help requests wouldn’t then be coming the ChaosGroup way, leaving them free to support real issues with the software, rather than with the user’s setup or lack of foresight (see CLIPPING.).
Do what you please with your creations, and feel as you please about the job you do, but know it IS grounded in very solid and complicated maths, no different in nature than the one which made us sail seas or count the passing of time precisely: Optics and Trigonometry.
Ignoring or disliking the fact (and the fact that you DO do that type of maths intuitively all the time, by evolutionary design) won’t make it go away, nor it will make shadows go a way they ought not to, or reflections appear where they shouldn’t.
I think the beta groups could do with you (and Gavin) onboard, why haven’t you two lazy a**es applied yet? ^^
You would LOVE some of the stuff that’s being worked on (and under NDA, ofc.)
Not everything will work, which is the beauty of RnD, but the beta group is built and maintained to be very free in the debate and expression of one’s mind, and boy do we not disagree amongst ourselves many times, to then find a synthesis…
Edit: I am on the beta group and love reading through, but it’s for greater minds I feel haha.
I’m not on the nightlies though!
So let’s assume you have a list of LUT presets and you choose one that you really like, then save out the image. You then need to apply the LUT in some other software, so how are you going to access the LUT’s that are in the vfb presets list? Are they seperate files that are installed with vray? If so, why not just do a google search for film LUT’s and download some free ones, or buy some?
What you’re asking for is a set of free LUT’s to be shipped with Vray really, rather than a presets panel?
Ahaha I’d love to just download some free ones, and have but the ones that ship with Octane aren’t available as LUTs ANYWHERE.
Can anybody explain what the “Covert to log space before applying LUT” option is doing. I’m assuming log is a mode like SRGB?
I can’t seem to get the same result in photoshop applying the same LUT
DISPLAY luts aren’t baked.
Color Mapping which is clipped to 1.0 IS baked, and into a clipped image at that (the curve itself contains no info on how to look up values above 1.0).
Which is what those curves, and Octane, do (you can NOT apply the curves and have an unclamped image. Not in the VFB, not saved on disk. Apply the curves, and the image is clamped.).
As for the luts list, here’s a few questions i’d need answered to mock a UI up, ideally with each point backed up by example workflows and proper documentation, so that evaluating how to proceed is clear:
Can you name a few general purpose LuTs you’d like added?
I’m sure i could find and convert them in nuke for you to load in the VRay VFB.
Once those are done, would you still want a dropdown to load them?
Would you want a warning when the loading of a LuT changes your display color space to Log?
Should there be a checkbox to make sure the output is linear?
What should be done when a LUT is loaded into the LUT dialog and another is preselected?
How would you make very clear which of the two is applied, or if they’re being applied chained, and if they are, which one is first and which one second (as order matters, very often)?
Would someone not want those presets converted to OCIO, and should we then not make sure we add the dropdown for OCIO descriptors too?
But then, should they match the ones for standard LuTs, or should they be of a different batch, given OCIO is more modern, and has less of an heritage in production to deal with?
Most of all, how would we do all that without making the VFB unwieldy and overcomplicated to use, catering for those users which have been crying out for an UI overhaul and simplification?
Right now, most of the complicated and potentially hazardous color science is relegated to fairly complicated steps across the UI, which insures only those with a precise need will bother, and one can suppose those users know what they are doing.
Add LuTs as a dropdown, and well, you are exposing that to your average joe which needs them like a fish needs a bicycle, and which will likely rue the limitations of such an approach (when mishandled and not backed up by proper post) and wonder why was it put there in the first place.
But the latter are my fears, not actual data.
The questions above are the questions i mulled when the proposal for a DDL of LuTs (1,2,3D whatever.) was suggested, and i still have no answer to any of them, or an answer which isn’t a worry, or leads to major risks for very little potential return.
I think my case can safely rest.
Wot. i was using the wrong bitmap type.
Thanks!
edit: but it’s still not finding the tiny sun (6px wide on a 4k dome).
I’ve attached a scene for you people to try and have that map cast the shadow it should from the HDR map (included, ofc. may need repathing).
Should you do a comparison with VRay (the dome is included) make sure you set the map intensity to 0.1 (up from 0.01, set like so to make the map actually visible in viewport).
White_Roomset.zip (555 KB)
Converts the Base map to a logarithmic color space before applying the look up table.
As I know the logarithmic color space, more closely mimics the natural light response of film emulsions compared to the liner color space.
This is film scan color space which provides better response in the dark end of the spectrum and doesn’t waste it on the dark end.
Hope this makes any sense.
Could you elaborate on this please? Are Chaos Group going to put into production a material scanner, or provide us with scanned materials, etc?
I think the easiest route - is to hire C# code-guy, to write you as much as you need 
BTW - I think, that there must be anyone, who is comfortable in coding for vray. We can even split the charges among several ppl, so it won’t be that expensive. What ya think ? Like a group buy or smth…
I can’t go too much into details.
What i can say, because it’s public knowledge, is that there is a VRayScannedMtl shader in max which is able to load scanned material samples as scanned by the patented chaos group scanner (based on x-Rite devices, I believe.).
In the beta group we tested them, and the results were quite remarkable indeed (albeit with the scanned material approach limitations. Some of which are being creatively tackled.), particularly for very hard to model BRDFs (cloth, very complex, layered metals, and so on.).
How they will choose to market it, is something I don’t know.
Well as I wrote in my message earlier, I would have seen a folder containing all the presets so you can loads from any other software afterwards and have the same results
I know Lele might laugh again, but did you try out in AFX, PS is really crap to manage colors and bit depth, AFX is the best one of Adobe suits to handle those.
I’ll need to re-read this when I have a bit more time to understand all what you just said as it’s a bit over my pay-grade for the moment, but what I can say is :
* yes it’s worth saving always to linear, and if a checkbox could be added to ensure that, I’d endorse that. Same goes for all the other post effects done in the VFB, for me they should not be saved out/baked in the saved exr, but I can understand why people would like to, so a checkbox could be the right call.
* apply lut should be kind of the same or as easy as going into Arion FX and apply the curves on top of your image, they make you swap between presets like octane does. You say it would be great to mix few of them at the same time? Well yes I didn’t even think of that, and yes I guess the order does have importance in that case.
* Just thinking out loud here, but if those luts are just a set of curves of RGB, why can’t we apply them in the curves straight then? Would that be better? convert them to *.bcurve and have a preset list of bcurve in stead? Then a simple tool to convert any *.ocio or *.cube to *.bcurve would make the trick.
* No idea of how we need to treat whatever goes over 1.0 float as I understand we don’t have that data. But could we not just leave the shape of the curve roll? If you create two points in besier curve, the curve reacts and lives outside the boundaries of those two points.
* Although I understand why you’d want to keep a LUT locked of but some of us, (like me^^) use those just for artistic purpose, and often as a starting point. So once I’ve loaded one in, if I can move points around (like if they where curves) and be able to save them out to reload them into my next soft down the pipe, it would be even better
Stan
Thanks!
Forgive me if I sound stupid here, I’m tired as hell!
Basically, I load the LUT into V-Ray, it blows out. I untick SRGB (assuming that also plays a part in further distorting things from their intended purpose?)
The LUT now (just for this tests sake, looks pretty good and I’m happy with it) is “correctly” being previewed in the VFB.
So now, in AFX, I load the 32bit source file-
What exactly are the steps involved to reproduce what I’ve previewed down the bottom?
I feel like I’m reliving the multi layered material research here, it’s endless but I’m on the brink of finding serious use for it
Cheers for any help.
Bastard 