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

[throb]

Hey everyone,

I have done a little tutorial on working in linear color space in VRay 1.46.xx

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

Basically it shows you what's been wrong with many apps for a long time and how to get all that dark stuff OUT of your renders and create more photographically accurate imagery.

let me know what you think

rob

[natty]

very informative Rob ... thanks

[Syclone1]

Tkx Rob, good tut

-dave

[siliconbauhaus]

very useful

wish I had max 7 though

[davision]

That color correction is done on an image that is greater than 24-bit right?

Otherwise, you could do it post, no?

Also, can the Vray frame buffer with its corrections be used with backburner?

[plastic_]

it's the same thing as using max's logarithmic exposure control, no?
i like the simple max interface with preview so i use it instead of manual curve editing or color mapping.

[throb]

That color correction is done on an image that is greater than 24-bit right?

Otherwise, you could do it post, no?

Also, can the Vray frame buffer with its corrections be used with backburner?

1) the image in the vray vfb is floating point. i turn off the clamping colors option. I will udate my docs to reflect that

2) you don't do it in post. you only do it to your viewing system. this means the vray vfb and whatever post app you use (nuke, shake, fusion, etc)

3) you do NOT burn in the curve. backburner doesn't care about the vfb settings. yes! i have successfully run hundreds of processors with this workflow in mind.

[throb]

it's the same thing as using max's logarithmic exposure control, no?
i like the simple max interface with preview so i use it instead of manual curve editing or color mapping.

it's not the exact same.

if we ask nicely, maybe the vray crew can add an 'apply inverse srgb' curve option to their vfb

vlado? peter?

[jujubee]

Good info. Where does your .64 value come from?

[throb]

Good info. Where does your .64 value come from?

it comes from looking at an sRGB correction curve and eye matching some numbers.

once the vray gods place the sRGB stuff properly into the vfb it will be a thing of the past.

[lukx]

hmmm...it's nice to know this trick but I got problems with colors with this method. Let's say client gives me some color chart in RGB. So I put this RGB number in material diffuse and when rendering with linearized method colors are washed out.

[throb]

hmmm...it's nice to know this trick but I got problems with colors with this method. Let's say client gives me some color chart in RGB. So I put this RGB number in material diffuse and when rendering with linearized method colors are washed out.

I would suggest putting the color in and then usin ghte sampling tool in the vray VFB (right click) to make sure the color is actually right.

i have done that in the past and for the first sample i show on the page.

[czoog]

Awesome tutorial, I've been playing with this method today and love it!

Thanks for sharing.

[Trapezium]

In Sony Vegas there is a preset in the Color Correction that says convert Computer RGB to Studio RGB. I've been using it allot lately. Anyone know if this is the same as sRGB? I couldn't determine from the links.

Thanks much throb

I see you got a link on maxunderground.com

--Jon

[throb]

In Sony Vegas there is a preset in the Color Correction that says convert Computer RGB to Studio RGB. I've been using it allot lately. Anyone know if this is the same as sRGB? I couldn't determine from
--Jon

Initially (I don't have Vegas) I don't believe that's the same thing.
Doesn't sound like it anyway.
What do the docs tell you?

rob