Request- Film Response Curves (Comparing Octane to V-Ray)

[vlado]

Colour workflows and gamut are just blackholes of mashing information that could really do some with clarifaction, but no-one seems capable of deciding which is best.

I'm not the right person for this either

Best regards,
Vlado

[grantwarwick]

If those could be converted into LUT's it would be a tremendous help, people are going to love it.

Another question I have is- Does V-Ray Calculate other objects specular highlights into the reflection pass properly?
I'm slowly piece by piece matching V-Ray to Octane but one thing I can't seem to figure out is this effect of V-Rays reflections being much darker and I believe it's because it's not adding the speculars of other objects into the calculation.
If you look at the octane image you can see the reflections are very bright and match the brightness of the highlight on the cylinder next to it whereas V-Rays secondary reflections look like they aren't accounting for the added specular.
Check the image below, some clarification would be greatly appreciated!

[vlado]

Another question I have is- Does V-Ray Calculate other objects specular highlights into the reflection pass properly?

Yes, they are calculated correctly. However, the "max ray intensity" option and disabled "reflective GI caustics" option may suppress bright highlights in reflections in order to avoid speckles and fireflies.

Best regards,
Vlado

[grantwarwick]

Yes, they are calculated correctly. However, the "max ray intensity" option and disabled "reflective GI caustics" option may suppress bright highlights in reflections in order to avoid speckles and fireflies.

Best regards,
Vlado

Feeling very stupid, literally just turned off reflective GI caustics! Thanks!

[vlado]

Feeling very stupid, literally just turned off reflective GI caustics! Thanks!

Ok, good to know. Actually, now that we have the max ray intensity option, it's probably safe to enable GI caustics by default... I'll have to think about it a bit.

Best regards,
Vlado

[Laserschwert]

We can write a tool that converts these to LUT profiles, if you think this will be useful.

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.

[3LP]

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

[Dave_Wortley]

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

[kosso_olli]

Actually, now that we have the max ray intensity option, it's probably safe to enable GI caustics by default... I'll have to think about it a bit.

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?

[3LP]

By the way, are both GI caustics enabled by default in RT GPU?
Cheers Stan

[vlado]

By the way, are both GI caustics enabled by default in RT GPU?

Only refractive caustics are enabled by default.

Best regards,
Vlado

[grantwarwick]

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.


I never thought I'd get V-Ray looking the same but I'm so close and It's pretty exciting!

[vlado]

Why would you ever need to adjust the gamma?

Best regards,
Vlado

[grantwarwick]

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

[grantwarwick]

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)