How to get better VRay renders (aka working in linear space)

[rpc212]

You have two choices as outlined earlier in this thread if you want to stay with a Linear workflow:

1. Use linear under "Color mapping" and apply the curve outlined by Throb in the Vray Frame Buffer with your gamma in the Max preferences set to 2.2.

2. Use gamma correct under "Color Mapping" and set the light multiplier to .45454. You also need to set your gamma to 2.2 under preferences in Max.

The reason to set the gamma to 2.2 is to make sure your Material Editor reflects what you are going to render material wise.

More detailed explaination are given earlier in this thread; right at the beginning with Throbs link:

http://throb.net/site_main/LinearWorkflow.html

and in this one:

http://www.chaosgroup.com/forum/phpB...ic.php?t=13724

So, lots of reading and experimenting ahead for those just coming on board with this workflow. I think, from what other more expert users have said in other threads, that if you want to composite then Throb's workflow and saving out to Open EXR format in 32 bit float is the way to go. This gives one the most options to "tweak" the rendering and change things without re-rendering while staying Linear workflow!

[Dman3d]

Well I am using the method "b" baking in using gamma color mapping.
I am encountering alot of noise in glossy reflections and I cannot seem
to get rid of it. It was mentioned earlier that one method was noisier than
the other (using linear with float vs. gamma color map baked) but I cant
seem to find clean information on how to handle the additional noise.

[plastic_]

OK i think i got it

one question: when i duplicate the vray framebuffer to a max framebuffer it displays the wrong gamma...
i like to duplicate frame-buffers to compare different settings, etc...is this possible somehow with linear workflow?

[jujubee]

Nope - not possible.

[plastic_]

so we need a vray framebuffer with history, or duplicate, at least....
maybe something can be scripted, have to check that...

[DaForce]

no you cant view them properly... but you can save them out of the max frame buffer properly.

[R2J2]

OK i think i got it

one question: when i duplicate the vray framebuffer to a max framebuffer it displays the wrong gamma...
i like to duplicate frame-buffers to compare different settings, etc...is this possible somehow with linear workflow?

turn off the curve correction then duplicate the VRay FB, if you leave it on the image will be corrected twice

I think I understand that correctly seems fine anyway

[DaForce]

but if your rendering using the other method, i.e. using the gamma color correction.
Then there is no color curve to turn off

[DF02]

This thread is great and very useful.
I did read it (and also the other tread started by Gijs) from start and it took me almost 1 week to finish.

Now,
I fully understand that there are different ways to apply this.
Questions are:

1. Throb said that his 0.64 curve is not exactly 1/2.2. So what gamma is throb cuve is then?

2. Someone posted before that the overall result of linearized image is a little bit too bright, less contrast and light shadows. I also feel the same on this ... and no I am not double correcting it .

I do mainly exterior scenes. Lack of contrast will make the rendering less nice, imo. Anyone doing exterior and can show some settings (light and environment) which has a good and sharp result?

3. How am I add brightness/contrast when I am rendering to VRay VFB? Looks like the one in Render Effects dialog doesnt affect VRay VFB, does it?

Thanks

You have two choices as outlined earlier in this thread if you want to stay with a Linear workflow:
1. Use linear under "Color mapping" and apply the curve outlined by Throb in the Vray Frame Buffer with your gamma in the Max preferences set to 2.2.
2. Use gamma correct under "Color Mapping" and set the light multiplier to .45454. You also need to set your gamma to 2.2 under preferences in Max.

[R2J2]

but if your rendering using the other method, i.e. using the gamma color correction.
Then there is no color curve to turn off

ah, of course, then you can just use the max frame buffer.

[Dman3d]

Noticed somethign in addition to the noisier glossies the reflection look much more accurate but I am having problems now with chrome and such really reflecting light sources, hot spots.
I suppose the noise is "normal" since I am no longer overlighting.

---edit---

you know, that was a duh moment, I get it now for the reflections. Still
overcharging everything a-la the "old" ways. At least now everything acts
is a more predictable way (I suppose that is relative right) thanks all.

[flipside]

I have a quadro fx 1100, but really, any video card with dual outputs should do the trick Tricky. Hey, didn't I meet you and Dan in LA last year? It's hard to tell by only the upper half of your face!

Hi!

I have bought a spyder, in the assumption I could indeed calibrate two different monitors connected to one dual output graphics card, as you guys are saying.

Now it seems I cannot do that... I had contact with technical support of the spyder, and they told me this:

you are a owner of a PC system. So Windows seems to be your operating system. With Windows it’s necessary to use a second video card, because Windows can’t handle two profiles on a dual head graphic adapter. It’s not our fault.

So I am desperatly wondering how you guys calibrate two different monitors connected to one graphics card!

[RErender]

If you are running XP pro SP2 + dot net :P there is a little app that will allow to load a profile for each monitor. It's available on the Microsoft site with a little searching.

I run xp64 so my method is to calibrate my main monitor and then manually adjust my second monitor to match. Not absolutely perfect but I can get it pretty close then if any color proofing is critical I'll do it on the main monitor

[flipside]

Thanks rerender, will do a search for it!

I emailed some of the comments from this thread to technical support, asking why it seems that people here succeed in loading 2 profiles in one graphics card.

Yes, this is the right device to calibrate more than one monitor and match them to each other. But you also need different LUT (look up table) and a normal dual head video card includes only one of them.

If you use a PCI express video card you are able to assign different adjustments to each display.

I'm getting more confused

[jujubee]

On two of my cards, I kept getting errors 'writing to the LUT (lookup table) with the Spyder software and another Colorimeter Nichols had mentioned. It's very disappointing to find that alot of this software does not support dual monitors yet.