mental ray materials

[mskin]

I'd like to know if and why i should learn how to use mental ray materials in my scenes. My hesitation is that typically i use MR for stills and scanline for walk throughs. In my experience, MR materials dont render so well in scanline so o stay away from them... mostly because i don't understand them. should i learn them? what about mental ray connections for standard materials?

 

Thanks in advance.

[psv1]

yes you should learn them.......

[pixelperfectg]

In my experience, MR materials dont render so well in scanline so o stay away from them...

Neither would Vray material, or Brazil R/S material, or Final Render materials.....Naturally, the "mr materials" aren't designed to work with the scanline renderer.

 

If you're using Max9, then really the only material you should focus on is the new A&D material. It should be the foundation for almost everything you need to make. It's a breeze to learn when compaired to the other shaders, especially with the included presets.

 

There's a whole world of shaders out there for mental ray. So, as you become more familiar with the program it would certainly be to your benefit to explore all the shader options. here's a good place to start:

http://forums.cgsociety.org/showthread.php?t=104578&page=1&pp=15

 

Jeff

[vizwhiz]

so here is a question

 

if you have started a scene with 'standard' materials

and now i want To use mental ray for The rendering engine

 

how do i convert The existing 'standard' materials To This new A&D mr style

 

(yes, i am going To read ALL The cgTalk Tutorials)

but i Thought i would just ask This in The mean Time

 

Thanks

 

Randy

[pixelperfectg]

Manually replace the materials, or a MAXscript could be written to do it automagically.

[mskin]

do they render better or faster? or better and slower?

[Justin Hunt]

They are quicker, give more control over glossies, refection resoultion, FG quality, built in AO and rounded corners, the list goes on.

 

They are very powerful and easy, the presets are great for "out the box" rendering whilst still being flexible enough to do just about anything.

 

Jump in the waters great!!!!

 

JHV

[vizwhiz]

well hell

 

here is a previous 'standard' material version of my present scene

i just started To change out all The 'standard' materials into mray

 

A&D materials

 

and now The project keeps crashing, cant get enough memory (??) etc

i might have To go back To finish This and Then get back To The material

 

A&D conversion

 

any ideas why A&D isnt working

 

i can render a small 'blowup' of The scene successfully

but i cant seem To get a 'final' render of The entire 'view'

 

Thanks

 

Randy

[pixelperfectg]

do they render better or faster? or better and slower?

Do mental ray materials render better/faster with mental ray than standard materials? Tough one to answer. For me, yes...I prefer the added realism from the mental ray materials (such as true glossy reflections & refractions). Does that added realism make my renders slower than the scanline...I'd have to say yes just because of the extra calculations required over the fake speculars of a standard material.

 

Now, are all the bells & whistels such as true glossy reflections/refractions required for realistic renders? Not always. Infact, on really diffused glossy reflections...at times, it's hard to tell the difference from a fake specular highlight, and a true glossy highlight. I'd say it's easier for "us" to pick out the fake specular vs. true glossy reflection just because we are more focused on this stuff than the average Joe. So the extra realism may or may not matter to your clients.

 

Bottom line, if you're perfectly satisfied (as are your clients) with the standard materials, nothing wrong with using those. But if you want to "kick it up a notch" and add things like true glossy reflections/refractions, or rounded corners, or persistence (glass color at depth), etc...then you'll want to use some of the mental ray shaders. Will your render times increase....mmmm, I'd say probably so. But I'd also expect your quality/realism levels to increase as well.

[pixelperfectg]

i just started To change out all The 'standard' materials into mray A&D materials and now The project keeps crashing, cant get enough memory (??) etc

I would probably put a new /clean A&D material (or even a standard material) in the global material override map and run a render to make sure it's infact a material vs. your render settings that's bringing it down. If it renders with the override basic material, then one of your materials is indeed causing the problem. If it doesn't render with the override...then it's some other setting not a material problem.

 

If it's a material that's bringing it down and you can narrow it down to which one..then post more info on it. Such as, does the material use displacement, if so what are your displacement settings, etc..

[mskin]

well, i appreciate the input and am giving MR materials a shot. So far i have had varying success. I will post something when i finish screwing around with it. I've noticed the glass material i created, using MR>DGS>GLASS(LUME) has sent my render time through the roof. Unfortunatelly i am super happy with it and refuse to part with it. maybe i will replace the glass with temporary material while I work the other materials out.

 

Any ideas on settings for WIP renders while keeping FG and GI on?

[AJLynn]

Wait, are you trying to use a Lume Glass as a map in a DGS? I'm pretty sure you're not supposed to do that.

 

Anyway, for WIP renders you can use Material Override (render processing settings) to do a simple gray material and/or just crank down all settings.

[mskin]

yes. i think its clear that i don't know what im doing, but it did render out without FG and GI. I was very pleased, but now, with FG and GI, this render which is a region about 1/4 the size of a 1536X1167 is going on 3 hours. I am using 4/16 sampling, but still, i am amazed at the time. same render without FG GI was less than a minute. Perhaps its because im using the glass shader as the diffuse of a DGS. I will keep you posted.

[mskin]

its odd to me. photon emmision took 3 hours, FG is almost through in about 5 minutes???

[mskin]

this is my first test. took way too long to render. will play with the glass material after dinner, take it out of the DGS slot. I would really like to acquire some transparency with the glazing.

[Justin Hunt]

What version of Max are you using?

If you set the AA to 1/4,4 it will render much quicker, although not as clean.

 

With Max9 use the new Ach&Design material for 90% of you materials.

 

Please post you FG photon settings, its easier to trouble shoot that way.

 

JHV

[AJLynn]

I think I see what's going on.

 

First, photons and exteriors don't mix - you just bounce them into space, and there's so much area to cover that you need a huge number of them. What version of Max are you using? If it's 8 or 9, try FG only with Bounces/Diffuse Bounces enabled (2 or 3 bounces should do it). Even if it's a mental ray version without multi-bounce FG, you're probably better off with FG only and using some fill light where you need it.

 

Get a ground plane in there, and use whatever kind of sky lighting you prefer. I've tried this in the past, and had good results: http://www.jeffpatton.net/Tips/Sky-dome.htm (Jeff's site is great.) But if you have Max9, the automagic sun/sky for mr works well. A good lighting environment for FG makes all the difference.

 

Also, for the glass, you don't need anything anywhere near as complicated as DGS or Lume in this application. If you have Max9, the A&D glass is fast, otherwise just set up something really simple with raytrace maps and transparency if you need it, the simpler the better. It doesn't even need real refraction, just some transparency and some Fresnel reflection.

[mskin]

would you use raytrace in lieu of DGS or in liu MR altogether?

[AJLynn]

mental ray can use a standard material with Raytrace inits reflection slot. I'm not sure whether that's the optimal solution. Sorry, I haven't tried this in an older version on mr in a long time and I don't have one with me to try it on, but I think another solution would be an mr material with Lume glass in the Surface shader, and a transparent shadow shader. There's also, of course, the Glass Physics-Phen material.

 

It's the kind of thing I'd figure out if I were looking at it. So I'd try that stuff, do some Google searching, download a scene file from jeffpatton.net that has mental ray glass in it, or wait a bit and hope that somebody who knoes what he's talking about chimes in

[AJLynn]

Just remembered a couple things to search for:

 

http://jeffpatton.net/MR-Caustics101.htm (don't use caustics in this scene, but that page does some good explanation of glass)

http://jeffpatton.net/Mental-ray.htm

 

I don't work for Jeff or anything, I just find his site very useful.

[pixelperfectg]

I made a few glass examples for the vizdepot site here:

http://www.vizdepot.com/forums/showpost.php?p=10203&postcount=36

 

If you put a glass(lume) shader into a DGS material and didn't turn off the reflections on one of those materials..then you're running double calculations and naturally that will send your render times through the roof.

 

Regardless, hopefully you'll find some of the glass materials I posted in that link useful. If nothing else they should make a good starting point for adjustments.

[mskin]

I've got to thank you guys. I've learned a ton through this discussion and exploring the materials here at home tonight. im having a blast and my renders are much improved. I will be posting some images for you to check out as i rebuild my model with these MR materials.

[Camby1298]

 

I don't work for Jeff or anything, I just find his site very useful.

 

 

Don't we all???

[vizwhiz]

i dont work for Jeff and i find his website extremely useful

 

i just wish his would get off his sweet little bippy @$$ and finish his 'impending' mray Tutorials

 

(just joking Jeff)

 

(subliminal hint 0-99999 goes here)

 

(not just joking Jeff)

 

impatiently waiting and holding my breath

hey i will even send you some $ right now

 

Thanks

 

Randy

[pixelperfectg]

lol, I hear ya!

 

I can tell you that nobody wants these vidoes completed more than I do! But I'm a stickler for details, and as such my O.C.D is in full effect when I'm working on these videos to ensure I have everything just the way I want it.

 

Another funny quirk of mine...I can't tell you the number of times I've had to re-record parts of my voice overs just because I said a word that had way too much "southern drawl" on it...lol.

 

...I have to get these things wrapped up soon before I lose whats left of my mind.