Mental Ray lighting (is there an answer)

[randymcbrayer]

Okay, I've been toying with Mental Ray in 3ds max for years now and have seen many people post different render techniques and styles but haven't seen a definitive (here it is rendered this way and here it is rendered the other) comparison that would solidify once workflow as THE answer for realistic renders at a decent render time.

 

I render restaurants (exterior and interior). In either case, my camera will always pick up some of the exterior. That said, I'll always have a sky in a render and will always need an exterior lighting setup.

 

So, MR sun/sky vs HDRI vs anything else. What will produce the best result? I realize I could probably set up the same scene two ways myself but am wondering if someone above my pay grade has ever done so and could easily explain it.

 

Thanks!!!!!

[numerobis]

I'm no Mental Ray user but there were a very good and detailed making of on ronenbekerman.com some time ago which really impressed me:

http://www.ronenbekerman.com/making-of-esherick-house-part-1/

Maybe you already know it...

[Justin Hunt]

I'd say that is depends on the scene. If the BG isn't really the focus of the view then stick with mrSun and Sky. HDRI's are great but you are locked into the sun angle in the map, sure you can rotate the image left or right, but not so easy if you want the sun to be higher or lower. HDRI's do give a nicer variation/ subtly in the lighting.

 

More often than not the sky gets replaced in post for a better quality one any way.

 

HDRI's with FG work well, especially now that environmental importance sampling has been better implemented in 2014.

 

jhv

[Francisco Penaloza]

There is not a ultimate way to do this, because every scene is different, That's way a good visualization artist worth his wait in gold ( or some currency ) if not rendering will be a push button deal.

Now if you are working for a company that always render the same, lets say a 3d floor plan, or same kitchen different furniture same camera angle, yes then you may find a render setup and lighting that will fit all you needs, but rendering exteriors and rendering interior is a complete different deal. Also rendering still still images is very different to render animations so the best you can do is learn the theory of the software and apply this to your scene, with practice later on it will be easy for you to identify what type of setup you'll need for specific scenes and what will be the possible problems to be concern.

For instance, MRay Sun/Sky VS IBL, one will give you speed and flexibility the other one will give you more color variations, softer lighting but longer rendering time, what to use? it depend of you, do you have time for longer renders? or are you in a rush to finish several images?

Should you use EXR or JPG? is your client done with color and finishes or he still want to try different schemes?

Does your client buy the color bleed of real world simulations deal, or he does think that no matter how red are his walls and floor, the ceiling should still be white as white can be? Flexibility, Physically correctness, Speed, artistic expression, Architectural point of view and more this are all variables that we deal every day, and this is what will decide what tools and work flow to use.

[Matt McDonald]

We work on multi-project rollouts like restaurants or chain retail so I understand the desire for a "right way". As others have pointed out, there isn't really a "right way" but with projects like these there is a "my way" or "our way".

 

My suggestion is to start with your proto and follow a tutorial you like. Then start adjusting/tweaking settings to get a render time you are comfortable with.

 

That's going to be your "my way" until you learn something new or get sick of the way your renderings look. Then you start folding in tweaks.

 

Oh, and an interior is definitely going to be different than an exterior.

[randymcbrayer]

Thank you all. Each of you make great points.

 

My work is exactly like Matt's. Retail rollout of restaurants and slight tweaks on design from one project to another. I will be training two team members here shortly and want to make sure I am not taking them down a road they shouldn't be on.

 

Numerobis - I stumbled upon that tutorial a few months ago and have been using it for my work presently. I do think that he lost me at one point where he spoke about his original lighting setup vs his cloudy setup and night set up. I am currently using a MR Daylight System. The tutorial mentions mapping a background image to a skylight but you don't have that option with the Daylight system. Am I supposed to add a sky light in addition and then decrease the multiplier on the sun the image isn't blown out?? Just curious.

 

Justin - Background is never really a big deal in what I've done. I think I'll stick with the Daylight system and then just photoshop in the background as needed.

 

Francisco - You've introduced a term I haven't heard before. Being that I've rendered for about 8 years now that might be bad. EXR vs JPG. What is EXR?

 

Matt - I like the terminology - "My Way". I have about 3 my way's going on right now and really need to nail down which one I move forward with.

 

Thanks again all for taking the time!!

[Matt McDonald]

I've got a few "my ways" as well. One, is the fastest, most reliable light setup I have. This is the file that I assign to my staff members for projects. Another has a few tweaks or things that I have been trying out. Primarily I use if for testing but there is a feature or a setting I think will be beneficial on a project I have my team member work from there. The goal of the second one is always to eventually replace the first once all the bugs are worked out. Then I have several scenes that are generally a hot mess, all of the things I am trying out. Sometimes competing techniques. Obviously, those don't get assigned but they are nice to have because I don't worry about screwing anything up.

[Francisco Penaloza]

The tutorial mentions mapping a background image to a skylight but you don't have that option with the Daylight system. Am I supposed to add a sky light in addition and then decrease the multiplier on the sun the image isn't blown out?? Just curious.

 

I that tutorial he is using the skylight so he can get the effect produces by IBL, soft multicolored lighting, as a problem in early version of Max this would not create a hard or accentuated shadows, that's why he added the extra photometric light.

If you want to stay with the daylight system, you can add the image to your MRay sky, just drag the MR physical shader from the environment panel to your material editor, then you have 2 options, add the image as background or add it to the Haze shader, this way M Ray sky will take the colors from your image to lit your scene.

This is not necessary if you like the color of Mental Ray physical Sky, that also render faster.

 

Francisco - You've introduced a term I haven't heard before. Being that I've rendered for about 8 years now that might be bad. EXR vs JPG. What is EXR?

 

EXR is a High dynamic range image format that help you in 2 things, keep your workflow linear with 16bits or 32bits and save multiple passes in one single file, that is pretty useful while working on animations.

 

http://en.wikipedia.org/wiki/OpenEXR

[richardvivanco]

For exteriors use system daylight only with fg with 2 or 3 bounces. If you have several windows or opennings you need to add some skyportals if you want to translate in a better way the light from exterior to interior. If is not important in your scenes disable skyportals.

In comparissons in my experience between system daylight vs IBL, i prefer IBL..more easy to configure and render in few time. Try it in combination with unified sampling.

[beestee]

I think the answer is fairly simple.

 

HDRi will produce the best visual result with more physically correct subtleties. An HDRi setup will render slower.

 

MR Sun/Sky is intended to mimic reality but falls just slightly short of HDRi in terms of reality. An MR Sun/Sky setup will render faster.

 

Using HDRi for the first time will be a small challenge compared to the MR Sun/Sky. HDRi also requires collecting of very large files, sometimes at additional cost for quality sources.

 

Of course both of these methods are for simulation of natural exterior daylight, and if you are rendering exteriors the difference will be more obvious. When rendering interiors little difference would be noticed unless, by design, your interior scene is bombarded by natural daylight.