MR Sun Color

[Crazy Homeless Guy]

This may be an obvious question, but does anyone know if it is possible to take the MR Sun out of Physical tune in any other than the red/blue? I would like to make the sun add a little gold to the sun, but can't find a way to do it. I tried increase the read, but it increase the red. I might be able to drop back and use a IES sun, but I am not sure that will render proper area shadows. ...Or at least from my quick test, it doesn't seem to be rendering proper area shadows.

[mattclinch]

i think you can detach the sunlight assembly and tweak the colour manually. might be worth trying that.

[Justin Hunt]

you can also adjust the saturation of the colour, which might help. adjusting the haze also affects colour . Couple these with the white point in exposure control.

 

Just a thought

 

jhv

[Crazy Homeless Guy]

i think you can detach the sunlight assembly and tweak the colour manually. might be worth trying that.

 

Any idea how to do that? I tried dissembling it, but was only had the very basic MR Sun parameters left. Still no color control.

 

you can also adjust the saturation of the colour, which might help. adjusting the haze also affects colour . Couple these with the white point in exposure control.

 

I haven't played with haze a whole lot, so that may help, but I have played with the saturation a great deal and have really been amused with it. I find the MR Sun System quite limiting in its controls.

 

I have been doing a lot of experimenting with different setups, but the shadows and consistency across large areas makes the sun system useful. It is lack of controls when it comes to temperature that is frustrating.

[SandmanNinja]

From Brian's MentalBoutMax series - Overview Series - M3 - Interior Lighting Part 2

 

Non-Physical Tuning - gives you control over Saturation and Red/Blue tint. If the image is a bit washed out, just dial down the saturation.

[TenjinVisual]

Maybe you can do some changes to the expsoure node? Tint the White point?

[Crazy Homeless Guy]

From Brian's MentalBoutMax series - Overview Series - M3 - Interior Lighting Part 2

 

I don't really understand why I would dial down the saturation if the image was washed out, my inclination might be to do the opposite.

 

But... I really think the Red/Blue tint controls are questionable, and not the best solution on Autodesk/Mental Images part. A Kelvin control would be a lot more informative, and provide me with a great deal more feedback on what I am actually adjusting.

 

However, I have spent a great of time trying to adjust them to get a neutral white point. If I could use the Red/Blue tint to dial in a perfect white point, then I might be in business. Part of the problem is that there a large amount of green present when I really start looking at things.

 

Maybe you can do some changes to the exposure node? Tint the White point?

 

I have been playing with the white point in the Physical Camera exposure control for about a year, and have been mystified by that also.

 

If I adjust the white point in a way that I feel it should work, I wind up with unpredictable results. I feel I should be able to set the white point to somewhere around 5780k on a perfectly sunny day, which the computer should be mathematically perfect at creating. I can then place a perfectly, 100% white box in my scene, and sample the side facing the sun. The RGB numbers on that sample should be nearly even in each channel. Unfortunately they are not. With the default settings for a perfect sunny day, the green is the prodominant channel when the white box is spot checked in the frame buffer.

 

In fact, I have adjusted the white point witht he default settings from 5000k to 7500k and never found a neutral balance. It wasn't until I was around 7400k that the red and green balnced out, but the blue was still trailing way behind.

 

I do have another study scene going where I have the white point set to 100 kelvin, and I using the red/blue tint to adjust the image. In that test scene, I have the RGB of the white materials within about 1% of each other.

 

Maybe I am just being dense on this whole issue, and I am either not understanding the fundamental concepts, or simply adjusting the wrong settings.

 

I am doing several studies on trying to find the most effective way to control this, and I am sure i will eventually get there. In the meantime I continue to have concerns about the accuracy of the daylighting system, and the benfits it provides when it comes to adjustments needed to set certain moods in renderings.

[Crazy Homeless Guy]

Today I am going to spend a little time playing around with the atmospheric controls, and see if that helps me get to the point I am looking for. I have been ignoring those controls for the most part, and maybe that is the problem.

 

The quality of light is maybe the most important aspect of a successful image, so it bothers me a great deal that I can't gain more control over the sun. Sure, I can light using other techniques to get the look I want, but other light don't have the consistency over the scene in combination with area shadows. Those two aspects make me want to try and solve my color issues with the sun. Doing so will give me more flexibility.

Edited October 10, 2009 by Crazy Homeless Guy

[Koper]

Ok, I'm not familiar with MR but here's what I'll do with vray as I think the same can be applied with MR.

 

As we use a vray sun, we also use the vray sky, an this is what makes the color, not the actual sun object. And I think MR does the same.

 

These maps (vray sky, MR sky)are applied in the environment background. You can then drag it to your material editor. Place the map in an 'OUTPUT' material, then 'Enable Color Map' and go play with the RGB values.

 

Hope this helps G'luck

[pixelperfectg]

If you want to use kelvin controls for a sun light source, see if this helps:

http://mrmaterials.com/jeffs-blog/106-kelvin-controlled-sunlight.html

[Crazy Homeless Guy]

If you want to use kelvin controls for a sun light source, see if this helps:

http://mrmaterials.com/jeffs-blog/106-kelvin-controlled-sunlight.html

 

Thank you. This is exactly what I needed.

[Crazy Homeless Guy]

Ok, I'm not familiar with MR but here's what I'll do with vray as I think the same can be applied with MR.

 

As we use a vray sun, we also use the vray sky, an this is what makes the color, not the actual sun object. And I think MR does the same.

 

These maps (vray sky, MR sky)are applied in the environment background. You can then drag it to your material editor. Place the map in an 'OUTPUT' material, then 'Enable Color Map' and go play with the RGB values.

 

Hope this helps G'luck

 

This worked for control on the MR Sky, but I had to add a couple of steps.

 

MR treats the MR Sky different from Vray in that the Sky in the environment slot is responsible for reflection and background only. It does not appear to have an effect on the lighting solution. Once I drag the MR Sky from the environment slot into the material editor, I can unlink it from the sky for the lighting solution, and modify the look and color, but again, this does not effect the lighting solution.

 

I found a workaround by switching my daylighting rig from using MR Sky to simply Sky. This is an older Sky system that I do not believe produces light as well as the MR Sky. But... the Sky has an option to use a map. So, I can drag my MR Sky map that is referenced in the materials editor to the map slot on the Sky option, and actually use the MR Sky to illuminate the scene as a map instanced from the environment slot.

 

Did that make sense?

 

Anyway, so setting it up this way then allows me to then adjust the colors of the MR Sky by first placing it in Output material like you have suggested, enabling the color map, and making my adjustments with the RGB curves.

 

It is a lot of links, and might easily become confusing, but it gives me a great deal of control over color and looks. More so than what I had on Friday.

 

Attached is a reference image to the solutions I am getting now, with the combination of the Kelvin sun, and the Output map adjusted sky. It still needs work, but I am getting there.

 

I just opened a old model to test the setup on, so ignore the fact that I forgot to cop benches and some of the site walls. Meaning, people are sitting in mid air. Also, I was testing a lens shader that I forgot to turn off, which is the reason for the DOF.

 

Also, the shadows are a bit to blurry for the current sun angle, and the sky slightly to dark for how the sun is above the horizon. But the quality and color of light are a lot more inviting. The color currently be to red, but warmer colors are more inviting than the green tinge I feel I was getting with the stnadard MR Sky and Sun setup.

Edited October 11, 2009 by Crazy Homeless Guy

[Koper]

its got somewhat of an autumn feel to it.

 

I'd suggest to script yourself all the linking of maps and so-on to get the setup quicker, or just save a standard scene for yourself

[Dave Buckley]

anyone get an error message when loading max after installation of shaders?

 

i get something along the lines of "line 15 requires ray 3.6?????? this is 3.7??????"

 

can i ignore this?? kind of annoying though that it pops up everytime i open max

[Crazy Homeless Guy]

I have this running in 2009 without a problem, and decided to make it function in 2010. I was having problems getting the blackbody to show as a shader choice in 2010. I looked at the difference between the base.mi files. The 2009 one looked like this...

 

declare shader
color "mib_blackbody" (
                 scalar                     "temperature",
                 scalar                     "intensity"
                 )
                 version 1
                 apply light,texture
                 gui "gui_mib_blackbody" {           
                                 control "Global" "Global" (
                                                 # "hidden"
                                 )
                 }
 end declare

The 2010 one looked like this....

 

declare shader
                 color "mib_blackbody" (
                 scalar                     "temperature",
                 scalar                     "intensity"
                 )
                 version 1
                 apply light,texture
 end declare

So I modified it to look like this....

 

declare shader
                 color "mib_blackbody" (
                                 scalar                     "temperature",
                                 scalar                     "intensity"
                 )
                 version 1
                 apply light,texture
                 gui "gui_mib_blackbody" {           
                                 control "Global" "Global" (
                                                 # "hidden"
                                 )
                 }
 end declare

And that worked, the blackbody now shows up as a choice when working with the puppet direct light shader. However, I know get the following errors in the Mental Ray message window roll out...

 

API 0.0 error: found second definition of GUI "gui_mib_cie_d" using first

API 0.0 error: found second definition of GUI "gui_mib_blackbody" using first

 

I don't think this effects the functionality, but annoying just the same. I would rather have no errors on startup.

[pixelperfectg]

By doing that you've defined the blackbody shader in two places.

 

FWIW in my blog entry about Kelvin controlled sunlight (end of step #3) I provided some specific info on unhiding the blackbody shader in 2010 if needed.

[Crazy Homeless Guy]

By doing that you've defined the blackbody shader in two places.

 

FWIW in my blog entry about Kelvin controlled sunlight (end of step #3) I provided some specific info on unhiding the blackbody shader in 2010 if needed.

 

Perfect. I remember seeing the note about 2010 being different now that you point it out. I simply forgot that I had read it.

[Scott Erstad]

I probably would have gone with a gold-ish spot and set the ambient light to a nice complimentary tone, then Photoshop after the fact to fine tune.

 

Scotty