Yes, YES, a thousand times YES!!!
I’ve stumbled over those response curve files a while ago and had no idea how to put them to use… I’ve asked in several forums and no one even replied. It would be awesome if these data would finally be available in a format that could be used in Max, AfterEffects, Photoshop, etc.
Triple that!
I’m so looking for a way to get response curves in AFX!
For the moment I’m stuck with Ps using arion fx but I’m so looking forward for a solution in AFX!
Be able to see then in VfB and them re-apply them in afx would be a game changer!
Stan
Vlado, if they can be converted to
CUBE, 3DL or LOOK files then we can use these in Photoshop (and probably all other compositing softwares) too for consistency
Enabling GI caustics still creates a lot of GI noise in a variety of scenes. Indeed, it often does look better, but is there a solution to this?
By the way, are both GI caustics enabled by default in RT GPU?
Cheers Stan
Only refractive caustics are enabled by default.
Best regards,
Vlado
Hey Vlado
Here is another wip as I work through my “Octane Look in V-Ray”
I have a new found respect for V-Ray. I guess sometimes it takes rethinking things to come up with a solution but once again, the biggest hurdle is the response curves.
The V-Ray Render is using the Motiva Exposure plugin for V-Ray but the response curve doesn’t look indentical to Octanes. The highlights are blowing out a little more and the colors are saturating a bit differently.
It’s not a massive difference but my goal was to make things near exact so that I don’t have to teach people a new render engine.
On top of that, once again, Gamma is another hurdle. I can adjust the gamma in realtime in octane. With this response curve I need to double it up. In V-Ray I’m not getting things exact because I’m using a custom curve.
So far there has been huge interest in getting these curves into V-Ray and I think for the amount of impact they can have on the overall realism, it’s going to be a great addition.
Why would you ever need to adjust the gamma?
Best regards,
Vlado
Some of the response curves have gamma baked in. So you apply them and the render goes much darker. you need to correct for that. I can adjust the gamma using color mapping but it doesn’t work with this colimo plugin
(I often experiment with completely random gamma numbers inside octane when swapping to different response curves also. It’s totally dependent on the lighting of the scene or the subject material but either way, having that extra layer of creative control can definitely be the difference between fake and real)
For me, the problem is not necessarily the embed of film response curves.
These are just film filters and, as Vlado said, i don’t find any relevance in using them now that the era of video-cameras is almost gone.
If you really want to apply such an “instagram” filter, you are free to do it in your compositing software… and if you want to have the consistency between your filter in compositing software and the VFB, then i think the LUT profiles are quite ok (unless there are any bugs, that need fixing).
Now, my actual issue, as Grant also mentioned and tested it, and as i have noticed it long time ago when i mentioned this to you, Vlado, about half a year or an year ago…(but i didn’t know exactly what was the problem or where to look into for doing any tests - Grant got it right though), is that the photographic exposure (specifically, the curves) are not working as realistically as they do in iRay or Corona (and now Octane - i haven’t tested Octane personally).
Vray comes with a flat linear curve that is hard and quite impossible adjusting to match photorealism exactly.
All in all, the image in Vray comes with more vibrant colors, and has stronger highlights and darks…(i render as 32bit .exr and apply the curves in comp) that i find quite impossible to balance in comp(using curves). So, as part of my compositing routine, on top of everything, i always have to apply a desaturation filter and 2 curve filters to brighten the blacks a bit and clamp the highlights a bit as well… in order to try to match iRay or Corona… and even then, i’m still not happy with the result. iRay and Corona seem to have a much more and balanced lighting and colors in the raw render.
Maybe it’s just me that i can’t get it right, but Grant noticed that too in his IronMan test:
Vray image has:
- stronger highlights
- darker darks
- more vibrant / saturated colors (even in the HDRI behind)
- falloff / curve / balance between bright points and darks is steep, not that mild: Look at the highlight on the golden part of the IronMan’s legs: Octane’s transition from highlights to the less reflective area next to that highlight is much more natural, while Vray’s is much more contrasty.
Carefully read Grants post again. He said that he used the Motiva plugin for the renders of Vray, which makes it look a little different. To really compare the images, we would need the raw images from both renderers.
Have you tired softclip? Take your render into nuke apply softclip node. With logarithmic compress. Should mimic film soft roll-off in highlights.
As in the film response curve, have you tired to make some? its pretty simple. Photograph Macbeth chart with film stock, use equalizer in nuke gizmo. To extract macbeth chart info. Export LUT out with your film stock.
Personally i think its best to keep film response curve with compositing side of things or DI (in nuke/ Baselight). As 90% time you would be working with a neutral graduated plate in 3D.
But a softclip would be nice to have in Vray.
What be cool is a normalize preview button in the vray frame buffer. To preview that you have information in highlights and blacks is not clipping.
That would be a cool feature to implement as a button in the VFB.
The raw renders are very close.
It comes down to shader differences. But that is near impossible to match as the EXACT same colors in Octane don’t match V-Ray whereas greyscale values do! Very weird!
Either way, it took me hundreds of attempts to get gold and other materials looking photoreal in octane. Now I’m actually insanely close in V-Ray! It just sucks I can’t adjust gamma AND apply film response curves from motiva.
Getting there though!
(Edit: I’d love to show all the different examples but basically it looks like it’s impossible to render objects with pure 255 colors in Octane, something often overlooked in V-Ray where you can get things rendering with pure solid colors. For example, in V-Ray you can get a pure red sphere completely red whereas octane introduces a small amount of green and blue into the mix resulting in a more realistic saturation. I dno, it’s going to require some more studying and hard evidence but I’m confident I’ve discovered some new tricks for getting V-Ray looking more realistic and they are totally not based on physical settings, I’ve gone down the more artistic path but I could never do that before octane because I didn’t have realtime feedback which is the primary reason you get away with it
Did you had a chance to see/compare the visual and render time difference that you would have between Vray RT GPU and octane?
Would be great to compare both renderers that use the same hardware/technology.
Although I’m always partisan for a better render output than a faster one.
I can understand that octane is faster than Vray for some situations, but against Vray RT GPU.?
I’d love to see a fair fight 
Unless it’s not possible to get what you want to achieve in RT GPU because of missing features.
Stan
V-Ray is faster by a considerable amount so far but that is with adaptive mode. Octanes power comes from it’s initial passes in the first 20-30 seconds allowing for realtime feedback.
Because V-Ray is so optimizable I can comfortable half the end render time it seems!
Grant, if you set a red colour, and the renderer doesn’t output PRECISELY the same colour (times your lighting), the renderer is wrong.
For if it wasn’t, then a renderer may decide your pure red would be mighty cooler if it looked a tad more toadish green. And then your spheres as cubes, and your straight lines as spirals (perception is, after all, personal, right? Perceptual rendering is something which scares the socks off me.).
All this talk of “photorealism” going amiss in VRay (with a SLEW of BRDFs, provenly accurate radiometric equations, highly customisable render bias) while being present in Octane (ONE specular BRDF. Two tracing modes which fall to bits when a few GI bounces are used, no matter the tweaking one inputs in the controls. ) which can’t even render a pure color, set my blood boiling.
MATHS is king in the rendering world, and evaluating what looks photoreal and what doesn’t should be done -at least in public- with exact references and complete disclosure of the setups used, or avoided entirely, for without objective data backing the claims up, the exercise falls into the realm of rumor (or personal preference. just as worthy, for public consumption.).
Besides this, given the camera response curves are mono-tonal (ie, they simply represent a brightness curve which ain’t linear, but kinky due to the patchy response of chemical film across the ranges), there is no way applying those to a vray render would produce a hue skew like the one you described for Octane.
I am on record OPPOSING the introduction of OCIO and more advanced LuT controls in the VFB, precisely because it would add one more confusing layer for most users, while those which would really work with an OCIO workflow would know they don’t need to see the LWF renders skewed in the VFB by a custom LuT (rather, one would do that in post, lest one ends up chasing fringe values in non-linear color spaces for the rest of time… If any of you ever lit under Log space, you’d know.), so i guess to some it’s no news, but i have yet to see one single case of VFB-baked color controls which can’t be replicated in post and as such, to ME, they are a low-to-no-priority avenue.
We render unclamped (don’t we?), so nothing is precluded to Post as far as image and colour treatment goes.
(New message as forum limit max upload files to 5)
Saved file from the VFB (where your said the full float is supposed to be computed ):
As you can see, simple scene where both results should be exactly the same.
I just overlid the scene and compensate with the exposure in the VFB but the visual results in the VFB are just not usable and the exported results are not right either.
For me, if I can’t see it in the VFB, then it’s not worth using as I will not play by saving all my renders/elements to view them outside the VFB every-time I make a test render.
Maybe a check-box in the settings to enable the quick/bypass cheat the make the VFB faster would be a good workaround?
For those who don’t botter waiting a bit longer but who does want to have the “true” CC inside the VFB, it would be very welcome. 
Unless I’m mistaken and I’m doing something wrong in my example, the curves are just not usable in production for me.
Thanks
Stan
