PDA

View Full Version : Difference Between Vray And Mentalray???


3DBradley
01-30-2006, 05:51 AM
Hello Alll,

If someone could please answer my questions on this subject I would love to hear them.

1. really what is the difference?

2. can mentalray reach vray quality, and how?

3. is it something speacial about vray that makes 99% of first time users stuff turn out nice?

Thats all I can really come up with at the moment. Pretty basic questions but I hope this will get the ball rolling and have more people post their questions as well and we can get some ANSWERS and SOLUTIONS to our problems.

SO POST EVERYTHING YOU KNOW AND WANT TO KNOW!!!

Cheers

Adam

JDex
01-30-2006, 06:45 AM
VRay and Mental Ray are both powerful renderers that can achieve amazing results... the best way I can describe it (and I'm certain there will be disagreement) is:

VRay uses some very cool algorithms and techniques to achieve amazing results with a surprisingly small investment of setup time. This approach in many cases sacrifices some flexibility for less complex setup.

Mental Ray provides a very high level of flexibility making the setup time longer (especially until you really grasp it) and means that renders can be much more complex.

Mental Ray can achieve VRay like results if the user(s) is very skilled in Mental Ray and rendering theory.

MikeBracken
01-31-2006, 12:05 AM
I agree wiyh JDex. I use Vray, But IMHO Mentalray is, overall, more powerfull. For me, the speed of vray is hard to beat.

3DBradley
01-31-2006, 11:46 PM
Hey Guys,

So what your saying is if I care alot about control on the scene, then go MentalRay and if I need fast results with less control go VRay.

Well I picked myself up a copy of the "RENDERING WITH MENTALRAY HANDBOOK" so I will read through and due up a new scene and see what I can do.

If anyone else has any tips etc. for either MentalRay or VRay then post them....

Cheers

Adam

CupOWonton
02-01-2006, 05:35 AM
Overall Vray's GI is faster.
And it does reflections faster.
The downside is that Vray doesnt fake as much as MentalRay does.
So far there's no Fake-SSS shader or anything. You have to use actual translucency to get the result. This of course makes for a very good Architectural engine, but without a bit more material flecxability, sort of cuts it a tiny bit short on the cartooning CG edge. Just a bit though. Overall I preverr Vray to MentalRay, its just much cleaner for the speed you get.

CupOWonton
02-01-2006, 05:37 AM
Also keep in mind that vray hasnt been around as long as most of its compedators. Its got a ways to go.

floze
02-01-2006, 02:54 PM
Overall Vray's GI is faster.
And it does reflections faster.
The downside is that Vray doesnt fake as much as MentalRay does.
So far there's no Fake-SSS shader or anything. You have to use actual translucency to get the result. This of course makes for a very good Architectural engine, but without a bit more material flecxability, sort of cuts it a tiny bit short on the cartooning CG edge. Just a bit though. Overall I preverr Vray to MentalRay, its just much cleaner for the speed you get.
The thing is that you could write your own sss shader for mental ray if you're not satisfied with the (imo great) misss shaders, and there's people who actually did that (e.g. http://animus.brinkster.net/, http://www.lightengine3d.com/).
I wouldnt call the misss 'fake' though, rather biased approximations to a natural property of light.*

Vray's indirect illumination solutions are more flexible imo though. Albeit it might introduce extreme bias due to the filtering in most situations, it's simply smooth and easy to control. I love the lightcache (or lightmapping?) in vray and I wish there was some filtering options for the finalgathering (pendant to vray's irradiance map) in mentalray.

I'm not sure how you measured the difference of speed for doing (raytraced?) reflections..?

*mainly because I'm concerned about my christmas gifts next year, right Master Zap.?

dprgb
02-01-2006, 03:51 PM
vray.info has some more info on the pending Vray 1.5 release - there will be a fast sss shader, as well as a few others. Perhaps the most interesting is the new HDR sampling method that can produce caustics from hdr images.

I've been using Vray for over 2 years now, and really like it. I can get the look I want quickly, and the distributed rendering is great for high-res / high AA architectural renderings. Some stuff I'll use mental ray on, and I'm looking at getting a copy of Brazil also (why not - you can never have too many rendering engines!). I think the key to Vray is it's QMC implementation - you can easily control the sampling on all objects. I can turn the qmc down and see preview renders incredibly fast (much faster and cleaner gi than mental ray) and then just crank the samples up for the final render.

But yes, one of the big differences currently is the materials. Vray has it's own material type that you pretty much have to use if you want to use all the lighting functions. Granted, you can make almost anything you want from this, but it's not as flexible as mental ray, where you can program your own shaders. I think the flexibilty of mental ray (and similarly renderman) is due to this customization. Big studios can have full time shader programmers to get the look they want.

Another thing not to be overlooked is the vray proxy objects - you can store meshes in external files and have them called during rendertime. I've done a few auditoriums with over 1000 seats where each seat was a proxy, no problems with memory and it actually renders significantly faster than if the objects were all instanced within the scene itself.

floze
02-01-2006, 04:40 PM
Another thing not to be overlooked is the vray proxy objects - you can store meshes in external files and have them called during rendertime. I've done a few auditoriums with over 1000 seats where each seat was a proxy, no problems with memory and it actually renders significantly faster than if the objects were all instanced within the scene itself.
I suppose you restrict this to the mentalray for maya/3dsmax implementations, thus you are right. But this does not apply to the mentalray standalone, which indeed might load 'external' objects at rendertime, even very flexible due to the geometry shader architecture. My experience on mental ray for maya is: generally the geometry-on-demand thing is working quite well - the only problem is that maya/3dsmax still needs to load and convert the objects first, eating up huge amounts of memory, making it sometimes impossible to render. Again, this does all not apply to the standalone.

k2k
02-17-2006, 01:29 AM
There is a really better way to go than choosing between vray an mental ray: and this is final render...
fR is nearly as flexible as mental ray and in all my experimentation (during 1 year) is real faster than vray (about 30% for the same result)...
The only reason than fR is not as popular as vray is the poor marketing politics by cebas... but if you are looking for a renderer with the best quality/speed fR render is far the best renderer on the market... (I have been using vray and brazil for a long time...).
Moreover a new version of fR will be released on March... resolving the only problem fR had versus vray: the displacement maps... and with its new engine you will be able to render multi-millions polygon scenes with ease...

floze
02-17-2006, 10:37 AM
There is a really better way to go than choosing between vray an mental ray: and this is final render...
fR is nearly as flexible as mental ray and in all my experimentation (during 1 year) is real faster than vray (about 30% for the same result)...
The only reason than fR is not as popular as vray is the poor marketing politics by cebas... but if you are looking for a renderer with the best quality/speed fR render is far the best renderer on the market... (I have been using vray and brazil for a long time...).
Moreover a new version of fR will be released on March... resolving the only problem fR had versus vray: the displacement maps... and with its new engine you will be able to render multi-millions polygon scenes with ease...
I'm still laughing about their 'benchmark':
http://www.finalrender.com/products/feature.php?UD=10-7888-35-788&PID=52&FID=478
...

cpan
02-17-2006, 12:42 PM
I'm still laughing about their 'benchmark':
http://www.finalrender.com/products/feature.php?UD=10-7888-35-788&PID=52&FID=478
...


mwhahahahahha 14 secods on an "old" 2ghz dual pc (probably an opteron that it's faster than many other new cpu's) at 640x480 for that crap :)))

oh and "several hours rendering..." for the path traced image... loooool :)) maxwell would have done the same image (with that level 1 like hard noise) in several seconds =))

is that page on cebas's website a joke or what? :D

notavailable
02-21-2006, 09:29 AM
yeah ok we're talking about fr for 3dsmax
far faster than mental and vray on complex scenes with gi and stuff, but only
for still images (using the fr:image technique)
if u want flicker free animations vray is the way to go
but mental ray has an unbelievable level of control

i now use mental and vray on a regular basis, but the main reasons fro abandoning
fr is lack of support for 3dsmax8 and lot's of tweaking to get flicker free animation (or extremely long render times with Hyper-GI)

i still believe it has awesome speed advantages, but it's only when u see a sequence of images where u understand the blotchiness u don't see in a still image
plus displacement isn't as good

using the mental ray connection in 3dsmax just renders like my hi-res model in zbrush
plus i get to use misss fast skin

so i think in the end vray for fast architectural animations and mr for complex, character oriented scenes (hair is also cool in mr). mental ray also supports photmetric lights (in 3dsmax) with ies files also a huge benefit (i havent;s tried them with vray, co i use their light).finally the raysat system and the whole idea of the same rendering system being included in the most used pieces of software (maya,3dsmax,xsi) make mr a safe choice
if u check out the MegaTK shader for mr u'll see what i mean

plus if someone says that nobody needs the complexity of the mr shaders their wrong, if nobody needed them no one would write them and movie characters (along with special fx) would look a lot lamer

CGTalk Moderation
02-21-2006, 09:29 AM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.