PDA

View Full Version : Gamma in/correct mode


Saku-Pekonmaki
07-20-2006, 02:10 PM
Hi all who show an intrest to this topic.

first of all I hope that this topic is in the right forum part, i did not find any corresponsive forum for this matter so I posted it here where as I work with 3ds Max.

It started for me as i was on an vray forum for months ago ( I find vray to be the best suited renderer for me ) and I saw the word LWF...... the only word that was similar to LWF i could think of was WTF, but i never heard of LWF. wich made me ponder the meaning behind it. so after an extensive search on the net, I found out that LWF means LINEAR WORK FLOW. such a retard i can be.

Linear work flow or LWF as its called in everyday use, is basically a way to work with colors in digital format to display it correctly on the screen.

to explain it a bit better there is a tutorial made by Throb in the following link. I thank him for this great explanation for five year olds like me.
http://throb.net/site_main/LinearWorkflow.html

where as we come to the topic of this thread.

there is an exctensive amount of calibrations that has to be made to gamma settings in the computer and the monitor to be able to work in a Linear space.
Why to do it? to cut down render times and increase realism.

So the short version of a setup could be something as the User jujubee on www.chaosgroup.com/forum (http://www.chaosgroup.com/forum) explains.

The forum with some extensive information can be found here...
http://www.chaosgroup.com/forum/phpBB2/viewtopic.php?t=10854

1. You should calibrate your monitor to 2.2 Gamma Workspace. This is independent of working in Max but relates to improving quality overall. Information can be found at the AIM-DTP website http://www.aim-dtp.net/index.htm and is very worth taking the time to read.

To calibrate monitor use a chart similiar to this. its a png version.
http://www.aim-dtp.net/aim/download/monitor_gamma/250.png

2. Now for the workflow. Set 'Max Gamma' (under preferences) to 2.2. Set 'Bitmap Input' in same window to 2.2. Leave output to 1.0 see picture here http://www.nmedia.is/nmedia/images/saku/max.jpg
-Bitmap input means that when you import bitmaps into your diffuse swatches, they will already be corrected to the new working space so that you don't need to use ColorCorrect plugin on these particular materials. This is your choice - Flipside likes to not set the bitmap input to 2.2 cause he likes to manually use Colorcorrect on all his materials. I personally think it's more work. *Just note that setting the bitmap input to 2.2 adversly effects HDRs/EXRs (if you plan on using them.)

3. Convert diffuse material slots to new workspace. It only takes a second or two for each mat. In each diffuse that you use, right-click your Diffuse vray color swatch and hit 'copy.' In the blank square next to it, click and choose ColorCorrect (a free plugin which you should install.) Paste the color you copied (right-click paste) into the the red ColorCorrect swatch. Set Gamma in this same rollout to 2.2.) Done.
( This process has to be done "only" to scenes made earlier than the correction of the monitor and max GAMMA )

4. Set 'Color Mapping' in Vray Rollout/Render dialogue to 'Gamma correction' Values should be '1 (dark)/.45454 (bright).'

5. Render your scene to Vray Frame Buffer (VFB), not the Max Frame Buffer. The VFB now displays the final image without having to change/add anything. If it is too dark, turn up your light multipliers and rerender.


so... now all crt monitor users can be happy with the color correct images that they produce.

so what about LCD users?

CGTalk Moderation
07-20-2006, 02:10 PM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.