LWF Poll

First topic message reminder :

I am always curious about who use this technique, if you do not know what LWF means, please choose either answer #2 or #3.

Alicecocoz wrote:Haha dami nag #3....dapat kasi nag post man lang ng brief description yung TS about this

weird that it seems to be quite the opposite in the official vRay forums.



my intention when starting this thread was to see how many use this technique, nothing more nothing less. that was it. that was my only intention. i did not say i was going to explain it, i do not know why people here think that i "HAVE" to explain it. i am not trying to be rude here but i was under the impression that people who did not know it would simply find out using the internet and not wait for an explanation in this thread. i do not visit this forum everyday, actually i just came back from like a 2 year hiatus from the old 3D Pinoy.

anyway the link from mushroom is correct, but in vRay SP3 a lot of the manual steps to achieve LWF will be automated. but to be honest its really very easy to do, just set your gamma to 2.2 (1.8 for LCD) in MAX and also check the input bitmap parameters to use the same, use the vRay frame buffer, enable view in sRGB mode, save images using override gamma (you can set this automatically in MAX), get used to the adjusted gray and color scales for solid colors and that is it. but again for SP3 most of this will be automated.

now ask yourself this question, if this was such a "waste of my time" technique, i wonder why the CREATORS of vRay even bothered to put it in SP3 in the first place......


LWF

Perhaps it's the TS's responsibility to give details on his topic. We don't even have to be obliged into googling it.

LWF wrote:
weird that it seems to be quite the opposite in the official vRay forums.

https://2img.net/r/ihimizer/img201/5595/chaoslwf.jpg

my intention when starting this thread was to see how many use this technique, nothing more nothing less. that was it. that was my only intention. i did not say i was going to explain it, i do not know why people here think that i "HAVE" to explain it. i am not trying to be rude here but i was under the impression that people who did not know it would simply find out using the internet and not wait for an explanation in this thread. i do not visit this forum everyday, actually there i just came back from like a 2 year hiatus from the old 3D Pinoy.

anyway the link from mushroom is correct, but in vRay SP3 a lot of the manual steps to achieve LWF will be automated. but to be honest its really very easy to do, just set your gamma to 2.2 (1.8 for LCD) in MAX and also check the input bitmap parameters to use the same, use the vRay frame buffer, enable view in sRGB mode, save images using override gamma (you can set this automatically in MAX), get used to the adjusted gray and color scales for solid colors and that is it. but again for SP3 most of this will be automated.

now ask yourself this question, if this was such a "waste of my time" technique, i wonder why the CREATORS of vRay even bothered to put it in SP3 in the first place......


LWF

It just happened that most of us here are not familiar with it. It's good though that you included option 3. But it's not enough specially when they start to ask that question. Anyways, thanks for clearing this matter up bro!

mushroom wrote:Lots of Work Flow i mean Linear Work Flow

http://www.aversis.be/tutorials/vray/essential_gamma_01.htm

even so, i choose no. 3.

Lots of Work Flow - good one

i am predicting that in a year or two (or even less) you will be using LWF. , 7 years ago we had this debate about vray vs. Brazil, vray was still at beta 0.7 then. i was a vRay fanboy and you were a Brazil fanboy back then, and now you are in the vRay camp. when vray SP3 becomes the most widely used version of vRay, more and more people will use LWF and so will you

LWF

alwin wrote:i choose #3 ! sana makita natin yung pagkakaiba sa may LWF at wala
para ma inspire naman tayo!

thank you for politely asking

many techniques, tricks, tweaks can be done to finish of a project, so that is not the best way to show how it works since there could have been a lot of Photoshop done on the image already. having a simple un-edited image is the best, no tweak, just two solid materials, a direct light and some sky (slightly blue). besides i do not have time to do 3 different renders from a single project using 3 different techniques.

NON-Linear Workflow using Linear color mapping, 1.0, 1.0, 1.0



NON-Linear Workflow using exponential color mapping, 1.0, 1.0, 1.0 (lights have been made brighter to simulate desired illumination equivalent to linear).



Linear Work Flow using Linear color mapping, 1.0, 1.0, 1.0



The 2 colored squares on the upper left were added in Photoshop. These represent the "true" paint colors used in the scene in terms of RGB values. These colors are actual bitmaps mapped onto the objects, not made in MAX using the diffuse colors.

The 1st image has accurate color, as with all linear color mapping scenes, but the light is too harsh and not enough bounced light in the shadows. Imagine if this was an interior scene with a small window, you get the point.

The 2nd image uses exponential color mapping, better lights in the shadows, less glare, etc. But the colors are going to get muted, and don't even go to vRay glass using exponential color mapping.

The 3rd image uses linear color mapping in a linear work flow (LWF). Notice the colors are true to the original paint and lighting is better, shadows are not too dark, also light will travel further inside a room for an interior scene. Also color bleeding is WAY better (try doing this in a white room with red carpet). Basically its the best of both worlds.

I know that you can achieve #3 using other non-linear means, like adjusting the RGB offset of the maps, darkening your textures in Photoshop, using vRay material wrapper, etc. If you are comfortable doing that I am not here to change you mind (or anyone else for that matter).

I simply started a poll.

LWF

Interesting stuff. Is this only available in Vray? How about MR?

Alicecocoz wrote:Interesting stuff. Is this only available in Vray? How about MR?

this can be done in ANY rendering application, however i do not know how to do it in MR since I do not use MR.

http://www.vizdepot.com/forums/showthread.php?t=3465

http://mymentalray.com/wiki/index.php/Linear_color_space

just did a quick search on Google. again, i am not an expert with MR so please look around further on your own. the only advice i can give you is that it is worth it (at least for me).

LWF

OK will do. I actually found a nice article. Tnx! BTW nobody is assuming you are an expert here. It just happened that you initiated this topic which is kinda new to us thus we assume you are "more knowledgeable" on this matter.

LWF wrote:

mushroom wrote:Lots of Work Flow i mean Linear Work Flow

http://www.aversis.be/tutorials/vray/essential_gamma_01.htm

even so, i choose no. 3.

Lots of Work Flow - good one

i am predicting that in a year or two (or even less) you will be using LWF. , 7 years ago we had this debate about vray vs. Brazil, vray was still at beta 0.7 then. i was a vRay fanboy and you were a Brazil fanboy back then, and now you are in the vRay camp. when vray SP3 becomes the most widely used version of vRay, more and more people will use LWF and so will you

LWF

wah, was that me.. i think you were referring to raymond back then, he was a brazil junkie, even when vray 1.09 was out. but it's true i did use brazil for a while since i never got my hands on a vray plugin then until you showed your meier stuff

sure man, as soon as LWF becomes easier to use then by all means count me in. anything to speed up quality and production. need to consider my clients' welfare now :p

thnx sir for your sharing! medyo excited lng kaya cguro ganun ang dating sayo ng marami...at saka sa poll my F**k kaya un ang ginamit ng karamihan...tuloy ngkakaroon ng misinterpret imho...thnx agen sir!more power for LWF...

ill choose #3 either. Im curious about this thing before and tried but I still dont understand. what a fish..

thanks sir

interesting i have a question though...

you've mention gamma 2.2 = 1.8 in LCD.
i will assume 2.2 is for CRT? if my assumption is correct paano bro ung file na natexturan using CRT monitor using low end pc's and will be transfered and rendered on high end pc's with LCD monitors? does the 1.8 value in LCD automatically adapt to the 2.2 value of the CRT?

kietsmark wrote:interesting i have a question though...

you've mention gamma 2.2 = 1.8 in LCD.
i will assume 2.2 is for CRT? if my assumption is correct paano bro ung file na natexturan using CRT monitor using low end pc's and will be transfered and rendered on high end pc's with LCD monitors? does the 1.8 value in LCD automatically adapt to the 2.2 value of the CRT?

yes and no. there is a preference in MAX that if checked will prompt you to adapt a files LUT/gamma settings (Load Enable State with MAX files), in a similar way MAX informs you about adapting the system unit scale of a file upon opening. as for using multiple displays in an office it gets more complicated. Ideally you do NOT burn in the gamma correction in you renderings, but it gets a bit tedious to always burn it in before sending it out to a client. you do NOT burn a gamma in by keeping your bitmap files -> output gamma settings to 1.0 and by not overriding the gamma when saving the image.

you can then later on apply the gamma in post using After Effects or Adobe Image Ready. Personally I do not do this and burn in the gamma at 1.8 universally. It might not be the most correct way of doing it but it gets the job done 98% of the time for me.

LWF

LWF wrote:yes and no. there is a preference in MAX that if checked will prompt you to adapt a files LUT/gamma settings (Load Enable State with MAX files), in a similar way MAX informs you about adapting the system unit scale of a file upon opening. as for using multiple displays in an office it gets more complicated. Ideally you do NOT burn in the gamma correction in you renderings, but it gets a bit tedious to always burn it in before sending it out to a client. you do NOT burn a gamma in by keeping your bitmap files -> output gamma settings to 1.0 and by not overriding the gamma when saving the image.

you can then later on apply the gamma in post using After Effects or Adobe Image Ready. Personally I do not do this and burn in the gamma at 1.8 universally. It might not be the most correct way of doing it but it gets the job done 98% of the time for me.

LWF

it means if we tick the option in preferences > Gamma & LUT > Load enable state with MAX file > we don't need to edit the gamma of the receiving monitor? say I am transferring a scene from a CRT monitor with 2.2 gamma values as per LWF intructions, my 3dsmax in LCD monitor will adjust accordingly without even changing the gamma value to 1.8 first? or should i change the LCD gamma inside max preferences gamma to 1.8 first before i work on the file coming from 2.2? and check the load enable state?

LWF wrote:

torvicz wrote:maybe it's time the thread starter shed a f***kin light on this....

well maybe if you asked a bit more politely....

there is also this thing little thing called Google.....


LWF

sorry dude, but un ung nakalagay sa poll mo....we are just repeating it...
don't be sarcastic, it came from you first, right?

Please read the replies, most of them if not all have this f!@#!$$in word...hehe

but we all want to learn everything useful thats why we are asking your explanation before, since you are the one who started the thread we assume you have the explanation...

kung sa umpisa palang sinabi mo na, na gusto mo lang ng poll
e di na sana kami nagtanong pa...para san ba ung poll mo?
para lang malaman mo sa sarili mo kung may gumagamit ng f!@!$kin LWF
o para ma-share mo sa min?

just asking.....

Sir LWF, Hope you dont mind.. i really like to learn this techniques. it would really help if you could give us some illustrative guide like screenshots of settings and result maybe. thanks a lot sir

torvicz wrote:

LWF wrote:

torvicz wrote:maybe it's time the thread starter shed a f***kin light on this....

well maybe if you asked a bit more politely....

there is also this thing little thing called Google.....


LWF

sorry dude, but un ung nakalagay sa poll mo....we are just repeating it...
don't be sarcastic, it came from you first, right?

Please read the replies, most of them if not all have this f!@#!$$in word...hehe

Point taken.

Below is a bit of a long explanation, so it may not be for everyone. This was posted a few years back by a person you guys should all know by now.

Hello,

Since there seem to be lots of confusion about the whole linear workflow and gamma settings things, here is a more complete description.

The source of the problem is that computer displays (CRT and recently LCD monitors) do not display colors in a linear fashion. That means that if you input a color like medium grey (RGB 128, 128, 128), when displayed on the screen it will *not* be twice as dark as pure white (RGB 255, 255, 255).

The result is that the renderings that you see on your monitor do not correspond to the actual colors in your images. To compensate for this effect, the images must be color-corrected so that you see the actual colors.

Since each monitor alters colors differently, there must be a way to calibrate different monitors to a common standard so that you can be sure that when you view your images on another monitor, they will look the same. This standard is known as 2.2 Gamma or sRGB color space. It was chosen because CRT monitors on average apply a 2.2-gamma transformation on the input colors. Therefore, correcting for 2.2 gamma requires only a little change in the displayed colors to fit them into the 2.2 curve.

Note that for LCD monitors, things are somewhat different. The LCD output is a lot closer to linear. That means that calibrating an LCD monitor for 2.2 gamma output requires very large modification to the displayed colors. When combined with the fact that some LCD monitors still have less than 24-bit color resolution, it means that lots of color resolution is lost during this transformation. Therefore, it is often better to calibrate an LCD monitor to display linear colors, instead of trying to fit it into the 2.2 gamma framework.

There are three main workflows that you can follow to work properly with digital images. Those are outlined below.

I. Working in gamma space /w gamma display

For this method, your monitor is calibrated to 2.2 gamma space, and your images have the corresponding inverse gamma correction baked into them.

Your images don't need correction when viewed directly on the monitor, since they already have the correction baked into them. However, when you use images for other purposes (e.g. as textures, or when printing), you need to remove the correction. Also, when creating images, you need to bake the correction into them before saving the images to disk.

For this method, you need to make sure that all your images have color correction applied. If this is not the case, and those images have been created with method II or III, you will need to correct them.

Note also that this method is not suitable for compositing purposes. In order to get correct results, compositing must take place in linear space - e.g. 50% gray plus 50% grey must equal pure white. This is not the case if the 50% grey have been already gamma-corrected.

In the old days of slow machines, CRT monitors and 8-bit image file formats, this was the preferred workflow, as it ensured that colors are stored with maximum precision and the most frequent operation on images - displaying them - is fast. With the advent of faster computers, LCD displays and 16-bit/floating point image formats, the situation is now different. All in all, this workflow is now obsolete and is not recommended.

The only situation where you would still use this workflow, is when creating content that you know will be displayed on a CRT device - e.g. animation that will be played on a television screen. Even in this case, it is better to use one of the other workflows internally, and only bake the gamma transformation into the final result.

II. Working in linear space /w gamma display

For this method, your monitor is calibrated to 2.2 gamma space, but your images are stored in linear space. The corresponding inverse gamma correction is applied on the fly when viewing the images.

You need to make sure that your applications can display the images with the inverse 2.2 gamma transformation, while keeping the actual image in linear space.

Also, you need to make sure that all images you acquire from other sources (textures etc) are also in linear space. If this is not the case, and those images have been created with method I, you will need to first un-correct them. There is no need to correct or un-correct images that you make yourself, since these are already in linear space. There is also no need to correct or un-correct images created with method III, as they are also stored in linear space.

If you are working with a CRT monitor, this is the preferred workflow. Calibrating a CRT monitor to 2.2 gamma requires only slight modification of its output. Further on, 16-bit and floating point image format ensure that the color display correction does not lose color precision.

To use 3dsmax/V-Ray with this workflow:
(*) Calibrate your monitor for 2.2 gamma output.
(*) In the 3dsmax Customize/Preferences/Gamma dialog:
- enable gamma correction;
- set the gamma to 2.2;
- check the Affect Color Selectors and Affect Material Editor options.
- Leave input and output bitmap gamma to 1.0;
(*) If a bitmap texture is created with method I and has gamma baked into it, you need to specify this gamma when loading the bitmap in 3dsmax, so that the correction can be removed.
(*) Do not apply gamma correction to your rendered result.

The only situation where you would break this and you can apply gamma correction to a rendering is if you know that it will be displayed on a CRT device that has no color correction - e.g. a television screen. Even in this case, it is recommended that you only apply the correction as a post-process and not bake it in the rendering itself.

III. Working in linear space /w linear display

For this method, your monitor is calibrated for linear output, and your images are stored in linear space. No color correction is necessary when working with the images, with the exception when you are using images (e.g. textures) created with method I. In that case, you will need to un-correct them before usage.

If you are using an LCD monitor, this may be the preferred workflow. In that case, no color transformations are necessary, except if you use images produced by method I.

Note that it may be tricky to use this method, as monitor calibrating software is usually designed to calibrate for 2.2 gamma. However, we need to calibrate for linear output (1.0 gamma).

To use this method with 3dsmax and V-Ray:
(*) Calibrate your monitor for linear output;
(*) Disable gamma correction in 3dsmax;
(*) Make sure all your textures are not gamma corrected. If a texture has some gamma correction baked into it, that needs to be removed first.
(*) Do not apply gamma correction to your rendered result.

The only situation where you would break this and you can apply gamma correction to a rendering is if you know that it will be displayed on a CRT device that has no color correction - e.g. a television screen. Even in this case, it is recommended that you only apply the correction as a post-process and not bake it in the rendering itself.

-----------

All in all, it doesn't matter which method you choose - but when you choose one, you need to stick to it.

Best regards,
Vlado

Anyway to summarize, since most of us work with a gamma display (CRT and LCD) it makes the most sense to use method II. the only thing that i would add is that since most of out maps are created with the gamma baked in, instead of manually setting the gamma for each map we use, let MAX apply it automatically by making the bitmap -> input gamma value 1.8 or 2.2. This way your textures will display and render correctly in your material editor.

Anyway, don't stress too much on this. As I said a lot of this will probably be automated in vRay SP3. So adjusting these values and doing these adjustments might not be worth it for you once you upgrade since it will be done automatically if you chose to use it or you might have to adjust the workflow in SP3.

LWF

hi LWF i've read this LWF techniques since years ago.
but as i go through with it i found something interesting techniques applied..
yung bitmaps na ma a apply with this LWF could still be same without burning them or making the images dull. coz sometimes when we render with the applied bitmaps, the final output on the render is not same with the image we have applied. i have question... do we have to change also these bitmaps their gamma's before applying them on the max file? or leave them as it is...or is that what they say double gamma correction??

Thanx and best regards....

torvicz wrote:but we all want to learn everything useful thats why we are asking your explanation before, since you are the one who started the thread we assume you have the explanation...

kung sa umpisa palang sinabi mo na, na gusto mo lang ng poll
e di na sana kami nagtanong pa...para san ba ung poll mo?
para lang malaman mo sa sarili mo kung may gumagamit ng f!@!$kin LWF
o para ma-share mo sa min?

just asking.....

my original intention was to get an asesement on how many here in the forum use it, the exact same reason why i did a poll on who uses CRT or LCD's. the main purpose of the poll was just satisfying a curiosity i have regarding a certain rendering workflow. the same reason why i would do a poll and ask, do you shoot with a Nikon or Canon. not really to discuss what is a better camera but to just see what people are using.

LWF

hi sorry for asking...

it is answered the above lines posted...hehe.


Thanx for the education.. choice choice lng namn talga yan.
but learning is still the best!

nice. just got a bump on my head though... who will really control the color output? is it the gamma or the artist itself? i will go for the latter... coz most of the times, true colors and textures in your eye is not the same as mine even if we both use linear work flow does it?

kietsmark wrote:nice. just got a bump on my head though... who will really control the color output? is it the gamma or the artist itself? i will go for the latter... coz most of the times, true colors and textures in your eye is not the same as mine even if we both use linear work flow does it?

Sir the same kaya yung tingin pag naka salamin yung tao?

reygerali wrote:

kietsmark wrote:nice. just got a bump on my head though... who will really control the color output? is it the gamma or the artist itself? i will go for the latter... coz most of the times, true colors and textures in your eye is not the same as mine even if we both use linear work flow does it?

Sir the same kaya yung tingin pag naka salamin yung tao?

ano sa palagay mo bro? i never used eyeglasses pa kasi e...

cubi_o: wrote:hi LWF i've read this LWF techniques since years ago.
but as i go through with it i found something interesting techniques applied..
yung bitmaps na ma a apply with this LWF could still be same without burning them or making the images dull. coz sometimes when we render with the applied bitmaps, the final output on the render is not same with the image we have applied. i have question... do we have to change also these bitmaps their gamma's before applying them on the max file? or leave them as it is...or is that what they say double gamma correction??

Thanx and best regards....

ok, in the Gamma tab-> Bitmap file -> input gamma place a value of 1.8 (or 2.2) this should make your bitmaps the same as how you see the texture when you open it in Photoshop (same color, no fading). now when you render it should look correct but make sure to override the gamma when you save it (if you want to burn in the gamma). Or apply the same 1.8 value in the Gamma -> Bitmap Files - output gamma and every image you save out of MAX will automatically burn the gamma in.

Again, this might all be done automatically in vRay SP3 so you might just want to wait.

LWF