aflack

I've been reading threads on LWF in Vray for about a month now but still can't seem to get my head round it. Can anyone answer a few questions below, it would be appreciated...

I'm using Max 9 and Vray 1.5 and just about getting my head around the new Vray sky and Sun system.

My understanding is that I need to go to Max/customize/preferences and then enable Gamma correction and change Gamma to 2.2, I have to tick affect colour selectors and affect material editor then select input Gamma at 2.2 and leave output Gamma at 1? This makes all the materials in the Max editor brighter and when i render the same image it makes all the materials darker in the Vray frame buffer window......is this all correct so far?

I'm using a Dell flat screen monitor so my understanding is that i do not have to change anything on this as it works in linear which means it has a Gamma of 1 so I don't need to change anything here?

Thirdly in the vray colour mapping roll-out I leave colour mapping set to Linear leave the darkness and lightness multipliers set to 1. Not sure about the vray Gamma control though do I leave this set to 1 as I have already changed it to 2.2 in the Max control settings?

Now is where I get very lost, it all comes down to the materials at the end and how to get them looking brighter in the render window. I have read about a values .454, 0.25 and 0.5, are these universal over-rides that i type in somewhere and all the materials change back to look like what they did before but being physically correct now?

What I really need is a step by step tutorial showing me exactly what to do (with pictures of the Max roll-outs) then explanations as to why I need to do them, if anyone can point me to one I will be forever grateful.

What really confused me was when i saw a post on the vray forum by vlado saying that there were 3 ways of doing LWF depending on whether you used a CRT monitor and an LCD monitor and the last one was working in linear space with linear display and this made it sound like I had to do adjust nothing because I was already working in a linear workspace.....yet everywhere else I read that i have to adjust my Gamma to 2.2..........ahhhh my head spins and I can't imagine everyone out there is still using bulky old CRT monitors!

Any answers would be greatly appreciated, basically I need a dummies guide to LWF with no technical talk.

pg1

LWF is a hard one to figure out have a look at this

I attached a text doc
Originally this was a word doc with images but it was 2 large to post here as a word doc. so its now a txt. with no images.

If you want to see the original it was written by Sawyer and a link to the original was posted on chaosgroup. (you'll have to search for it on chaosgroup I cant remember what the name of the post was)
After reading through this a few times LWF finally clicked with me
(thanks Sawyer) so hopefully it will help you.

it was written before vray 1.5 so also look at this which has settings more up to date.

Also look at this
http://www.cgarchitect.com/vb/19567-lwf-vray-1-5-a.html

I also posted a question on chaosgroup about lwf

http://www.chaosgroup.com/forum/phpB...6986&highlight=

Hope this helps
Good luck

Attached Files

lwfDocument.txt (6.0 KB, 345 views)

crazy homeless guy

leave the vray gamma control set to 1 if you are working with a floating point format, HDR or EXR

set the gamma to 2.2 if you are working with a non floating point format, TIF, Jpeg, etc...

setting the gamma to 2.2 burns the gamma correction into your image. it is less dynamic, but often it is just easier for Arch Illustrations.

to make colors appear correctly (lighter) in the frame buffer window, click the 'srgb' button at the bottom of the frame buffer window. this temporarily applies a gamma correction to the image so it displays correctly.

HOWEVER... if you are working in a non floating point format (TIF, Jpeg), and have the vray gamma set to 2.2, then do not check this, otherwise your image will appear bright, and no contrast.

could you link me to Vlado's post about monitors and LWF?

__________________
travis schmiesing

aflack

Here the the link to Vlados post....

http://www.chaosgroup.com/forum/phpB...ic.php?t=15303

Just quickly before I have a proper read through what both of you posted what what is a floating point format?

Thanks for your help.

crazy homeless guy

i probably should have used 'high dynamic range' instead of floating point.
http://en.wikipedia.org/wiki/High_dynamic_range

__________________
travis schmiesing

aflack

Hey PG1, I remember seeing that on the vray forum but his link has gone down I just wondered if you could send me the whole document with images to my e-mail address?

If thats alright then I'll pm you with my e-mail address in.

Thanks for your help.

aflack

It is starting to make a lot more sense now, one question......

If I am using a low dynamic range image do I leave colour mapping as linear or do I set it to Gamma Correction?

Thanks