daylight without log exposure

[antimatter]

Ok. Here in our little studio we're starting to use MR 3.5 with max 9 (32 bit). We're wanting to use the mr sun/sky daylight system without using logarithmic exposure. Can anybody give me a solid reason not to do this (besides making light setup nigh impossibly difficult). The reason we're not using log Exp is that the materials in the editor are so vastly different, and the only way to approximate materials is to render regions all the time.

That said, does anybody have any good solutions for using the setup (for interior shots)? Using GI and FG.

[Dodgeas3d]

As for a night setup you can use log exposure, just when sun goes down u can simply turn off exterior light in exposure controls, then night gets its color and is brighter.
I think that log exposure is required for dailyght becouse its physical intensity values.
Not using log exposure you wont get these nice blueish shadows and nice color bleed....othervise it will look lit by not a hdr environment.

and what do you mean "the materials in the editor are so vastly different, and the only way to approximate materials is to render regions all the time" i dont get it....

[hot chip]

hi Antimatter,

we have in the the GMRF Materialtest Rendering Packet a Daylightsystem without logaritmic exposure control and you have a animited background.

Look here: http://mymentalray.com/forum/showthread.php?p=1597#post1597

Download the Packet: http://forum.german-mentalray-wiki.info/viewtopic.php?t=188

[F3LIC3]

You just need to set the intensity in the sun and sky to a very low value like 0.005
It's important to use the same values in both intensities.

[antimatter]

The materials in the editor are drastically darker than how they render with log exposure enabled and setup properly. So it is hard to get a good feel for things until a render is viewed. (yes, using the MR renderer for the material editor). We use an environment ambient value of 0 (black). I've ran out of time and I'll probably edit this and add more tomorrow.

[hot chip]

hi,

i am use the mia_exposure_simple shader, that have more contrast and the highlights are much better. i have wrote a new mi_file, you have more overview, new default vaule and range settings.

http://forum.german-mentalray-wiki.info/userpix/5_my_exposure_controll_1.jpg

the mi-file can you download here, scroll down: http://forum.german-mentalray-wiki.info/viewtopic.php?t=251

Screenshot: mia_exposure_simple+mr_dof:
http://forum.german-mentalray-wiki.info/userpix/5_mr_metall_geflecht_daylight_1.jpg

testrendering:
http://forum.german-mentalray-wiki.info/userpix/5_exposure_max_vs_mr_2.jpg

[MasterZap]

The materials in the editor are drastically darker than how they render with log exposure enabled and setup properly.

This is because the log exposure control is sort of like a gamma, and you are not seeing your swatches in the material editor gamma corrected.

However, much of this is due to the rather poor defaults of the logarithmic exposure control. Set "Brighness 50 Contrast 80" rather than the defaults of "Brightness 60 Contrast 50".

/Z

[hot chip]

hi masterZap,


i am using the mia_exposure_control, because i can this shader using for the charakters in XSI. Later in my composting, have the max architectual rendering the same quality as my xsi charakter rendering. Max exposure have brightness, contrast, midtone an so on. The the mia_exposure use a another proceeded and i think it is better. The manual from the new mia shader collection is very good.

[Bahamut]

hi hot chip, can you tell me where i must paste that code, i've tryed to use the mia_exposure_simple that come from max, but i can't get good result:(

[hot chip]

hi bahamut,

what for setting do you use and is the max logaritmic exposure controller = off?

my default value for a 1unit=1meter szene and photometric lights ...

mia_exposure + daylight
- pedestal = -0,1 (black&white alignment / contrast)
- gain = 0,03 - 0,06 (as like physical scale)
- knee = 0,25 - 0,6 (start the compression)
- compression = 4,7 (compression factor)

mia_exposure without daylight
- pedestal = -0,1
- gain = 0,6 - 1 ** this is the important value **
- knee = 0,25 - 0,6
- compression = 2 - 4,7

PS: the compression value is for reduce the over exposure.

mfg
hot chip

[Bahamut]

thanks a lot hot chip, i've managed to make it work with photometric lights, but still can't make it work with daylight, the logaritmic exposure is turned off, and using daylight without it, the scene become over exposed, so maybe i must low the mr_sun e mr_sky value???
just to know, do you put the mia_exposure in the output slot of the renderer???:confused:

[hot chip]

the way is:

mainmenue -> renderer -> Camera Effekts -> Camera Shader -> Lens -> mia_exposure_simple

[Bahamut]

thanks a lot hot chip, the problem was that i put the mia_exposure in the output slot of the camera shader, so it worked as a post_production effect and don't as an exposure control
thanks for your help ^_^

[MasterZap]

FYI, another cool "trick" to get sun-lighting into the "traditional" light range is to actually change the max "physical scale", which defines the relationships between "real world" values and "pixel values".

Add the logarithmic exposure control, but set it to *disabled*. Then set the physical scale to 80,000 - this will make your sunlight be "below 1.0" in classical color math.

/Z

[Shimrod]

Add the logarithmic exposure control, but set it to *disabled*. Then set the physical scale to 80,000 - this will make your sunlight be "below 1.0" in classical color math.

/Z


Even if the log expo ctrl is inactive, some params always work ??? Oo

I tried yesterday the mia_exposure_control shader, using the method described in the manual (render an hdr and then tweak the params). I'm able to set the Black Point (pedestal, if I'm right) but I did'nt get changes with gain on the picture, just a kind of white fade on it (I started with the values given by hot chip, and using the same units ;))...
Now I remember that the max's log expo ctrl was choosen but disabled... Perhaps that's why changes didn't appear...

edit : forgot what I wrote before, that's okay now. I'm so stupid sometimes... I was tweaking the wrong shader... :o



I tried too to render once with the shader in the Lens slot, and once in the Output slot. As already said, the result seems to be the same (except the "on-the-fly" method for the 1st, and post-process for the 2nd), but with the 2nd one, rendering took a longer time.. (immediate with the Lens, several minutes for the Output slot) Is it normal ? Is it really the same process that controls the exposure ?





Okay, now let's go with the remain of my brain to the german forum to download the latest version... :D

[imageimaging]

TO : hot chip

You Post

"i am use the mia_exposure_simple shader, that have more contrast and the highlights are much better. i have wrote a new mi_file, you have more overview, new default vaule and range settings."


Then I go the link web,but I can't understand German!There is not one code.Would you please post the correct code here?

Thanks.

[hot chip]

sorry

my english is not so good, please look here: http://forums.cgsociety.org/showthread.php?t=445027

[imageimaging]

Thanks for reply.