Nume trying out Mental Ray

[Tim Saunders]

I'm going to give MR an honest try. I work with Vray and have no reason to switch, but since mray is free, you gotta try it out. I teach archviz at a community college and these are 2 super high quality test scenes I'm quickly trying out to test out the lighting. I'm not too happy with the resuts so far. Here are the settings:

 

Daylight system with mr sun and mr sky.

sun mult: 0.7

sky mult: 1.0

 

Final gather with mult 0.7-1.0, draft preset.

Gi enabled with mult 1.0

all other indirect illumination settings are defalt

 

Log exposure control with exterior daylight checked and some adjusting on brightness and contrrast.

 

How can I improve? I just son't see any contact shadows in the corners and where the cable supports are coming in contact with the collumns. Any suggestions? Are there any good tutorials for free out there just to get a simple start?

[Justin Hunt]

The mentalray tutorials that ship with Max are a great start, especially the interior rendering one, which gives a good explination of the Final Gather settings.

 

As to the mrsun and sky, leave the multipliers at 1. Log Exposure control is a must. Set the physical scale to 80000 and the other settings as desired. Also turn on Exterior day light.

 

For the contact shadows, use the Arch and design shaders with AO turned on. AO acts in two ways here, 1st in the traditional AO way and second to help focus FG samples where needed. I would recomend reading up on the A&D shader. There is a heap of information, especially the reasoning behind each of the settings.

 

Final Gather behaves differntly when used by itself and when its used in combination with Photons. To help learn start off with only FG, leave photons for later. Mentalray shanged alot in 3.5 making FG renders much easier and quicker.

 

If you like, you can send me the scene and I can set it up for you to reverse engineer what I have done. PM me if you are interested

 

Other great sources of information are http://mymentalray.com/ http://mentalraytips.blogspot.com/ http://jeffpatton.cgsociety.org/blog/ and of acourse Brian's Mentalbout max (cant remeamber the link thought)

 

There are alost of similarities between Vray and mentalray so alot of Vrays methodes apply.

 

JHV

[Tim Saunders]

Thanks a lot Justin. I don't have access to anything that physically shipped with the program. I wonder if the tutorials are stored in the install folders anywhere. I'm glad you said something about the A&D shaders. I didn't even think about that. So far it's just standard mats. I'll tinker a bit more, but I may take you up on setting up a scene for me to start with.

 

A side note: How does the displacement in MR compare with Vray Displacement? Vray's resolution is nice and crisp for close-up bricks, and grass as you well know. That could be a major tetor on the scale.

[Justin Hunt]

MR displacment works very well,

 

There are several ways of setting up displacment, On Jeff's web site he gives a very good workflow using hightmaps. It works slightly differntly to Vray in that it is quite dependant on the mesh density.

 

The A&D shaders are the equivilant (sp????) to Vray materials, only easier, and more versitile. The document I was talking about should be in the mentalray help files. A nice feature for learning this shader is the pop up tips, hover your pointer over the settings and an explination/ recomendation tip apperars.

 

JHV

[MasterZap]

Daylight system with mr sun and mr sky.

sun mult: 0.7

sky mult: 1.0

 

Final gather with mult 0.7-1.0, draft preset.

 

Basically, - in my opinion - you should never modify these multipliers unless you have an absolute reason to do so. I.e. FG multiplier should be 1.0 at all times, if you are not a movie studio trying to create some special effect, or you have a particular trouble you want to work around.

 

For example, your case of turning down the sun 0.7 and then turning down final gather 0.7 in practice cancels eachother out, only it lessens your diffuse bounces for FG.

 

I suggest you keep these at 1.0

 

Gi enabled with mult 1.0

all other indirect illumination settings are defalt

 

Good. Using mr Sun and mr Sky?

 

Log exposure control with exterior daylight checked and some adjusting on brightness and contrrast.

 

Log exposure can be nice, the photographic one in max 2008 is nicer.

 

How can I improve? I just son't see any contact shadows in the corners

 

Well, you did use "draft" FG settings.

 

There are two ways to get those; heavier FG settings, or use the built in AO in A&D material. I favour the latter, coz it's nice and fast.

 

and where the cable supports are coming in contact with the collumns. Any suggestions? Are there any good tutorials for free out there just to get a simple start?

 

As already mentioned, on your "Help" menu you should find the normal help documents, which should include the tutorials. You may lack the files supplied, but it's a fairly trivial empty room w. a. couch and a window.

 

And while that is a good general tutorial about FG and GI and stuff, in Max 2008 the tutorial for that scene would read

 

a) put a "mr Skylight Portal" in the window

b) Hit render

c) Done.

 

 

/Z

[ralopez]

Hey Tim, great start. I have been working with MR for just a little time, trying to get some of the setting for proper ligthing. Follow some of the suggestions given. Continue posting.

[Tim Saunders]

I will for sure. It's fall break right now at the college, so I won't be back there for a while (that's a side thing). But I'll keep the progress posted. I assume there are many people out there who have consitered giving it a try, and if it is as easy as it sounds, I think showing my progress will be helpful for them to see. I may never fully switch from Vray since I feel extremely confident with Vray materials and I love Vray Proxy objects. But using it here and there and with the college students may be fun.

 

And yeah, the photographic exposure control looked sweet at AVC2007. Has Max 2008 been publicly released then?

[Justin Hunt]

Absolutly, the way I see it, it an other arrow in your quiver. There are somethings that Vray does better and others that mentalray does better. There is also a large overlap between the two which makes switching between the two very effective.

 

The way Mental is being developed and promoted since Max9 is making a great impact in disspelling the myths of old. Mentalray 3.6 is promising alot and I am sure it will deliver.

 

Your time spent now will be well worth it, even if you never fully make the switch (and why should you)

 

Being a mental office (in more ways than one:D ) it has been interesting seeing the recation of new staff. People who have only ever used Vray in the past, some not even scanline. There is reluctance and great effort spent trying to switch us to Vray. Once they get started and are up and running, it is amaising to see the transformation. They become quite excited with the results and are supprised at how simple it really is. Within a couple of days they are production ready.

 

That being said I am still trying and learning Vray for the very same reason of putting arrows in my quiver.

 

JHV

[Tim Saunders]

Still experimenting with things with my class. I'm super excited about how good of a renderer MR is for no charge.

 

I'll still put V-ray against it in speed, but I'm sure some of you MR veterans have figured out some speed tricks.

 

Here is a small room I was experimenting with while my class was working. I'm pretty happy with it, but I haven't figured out how to improve the AA settings. I don't like the jaggy edges, and I got too lazy to read all the help pages. Anyone want to toss me a bone?

 

Scene info:

2 area omnis up near the ceiling, 1 free area to the left of the room for skylight effect.

All arch/design materials

Final gather on Draft preset and one bounce, no other tweaks.

[SandmanNinja]

looks good to me!

 

If you turn up the Samples Per Pixels (under the Render tab) MIN and MAX, that should give you a better AA solution.

 

min:4 and max:16 works well, but adds to your render time.

[Tommy Burns]

Some good stuff there for your first MR Interior

I think if you use the Sky portal system you might get a better result

The image attached was my first crack at the sky portal and I was very happy with the lighting. All I used was mr sun/sky and a portal across the window. There is no other light in the scene and the way it lit up the kitchen with photons was amazing. Would love to see one of your images done this way to see the difference. Thats of course if you have 2008.

[Tim Saunders]

I agree Tom. I experimented with that a bit at work, but the school has not yet upgraded from Viz 2008 which has the MR without the portal lights, physical camera and exposure, etc.

 

That's why I used the mrFree Area.