Vray versus Mental Ray Exterior scene

[paraganek]

Hi everybody,

this is a test scene rendered both in vray and mental ray to compare render times and GI quality.
There is one Direct light in both scenes to simulate sunlight (Intensity 1.0, Vray shadows in vray scene, Ray traced in Mental ray scene).
There is a Skylight light (Intensity 1.0, slightly blue) in the mental ray scene.
In the vray scene the GI Environment is set to 0.5.
There are no secondary bounces in the vray scene (otherwise the shadowed areas are getting much brighter).
Mental ray is using just Final gather set to comparable gi quality with vray render.
The render times are about the same. The mental ray render is getting nicer shadowing in details in my opinion.
Is there anything I could change in the vray scene setup to match the mental ray gi solution closer and still stick with that 17 minutes render time ?
Thanks for any suggestions

[img]ftp://visitor:newlands@ftp.newlands.cc/mr/vray01_lr.JPG[/img]
Link to hight resolution image ftp://visitor:newlands@ftp.newlands.cc/mr/vray01.JPG

[img]ftp://visitor:newlands@ftp.newlands.cc/mr/mr01_lr.JPG[/img]
Link to hight resolution image
ftp://visitor:newlands@ftp.newlands.cc/mr/mr01.JPG


[img]ftp://visitor:newlands@ftp.newlands.cc/mr/mr_vs_vray_details.JPG[/img]

[RErender]

You would have to use some sort of secondary bounces to get the same sort of detail in the GI, you could probably get away with LightCache at pretty low settings, somewhere around 350 samples. Shouldn't add too much time, probably about a minute.

Adaptive QMC @ 1 and 4 might be a bit quicker.

Are you using V-Ray materials? converting would probly save you about 10% time if they are not already.

[paraganek]

OK, I am getting there.
Still using just Primary bounces, set the IR map a little bit higher this time.
It takes 19 minutes now to render.
I am going to try Adaptive QMC 1/4 next time.
Any other suggestions how to keep this quality and match the faster Mental Ray render time would be greatly appreciated
(Otherwise my boss is going to switch our renderfarm to mental ray territory )

[img]ftp://visitor:newlands@ftp.newlands.cc/mr/vray02_lr.JPG[/img]
Link to high resolution image: ftp://visitor:newlands@ftp.newlands.cc/mr/vray02.JPG

Details in Vray render using IR map at -4/-2, HSph. 30.
[img]ftp://visitor:newlands@ftp.newlands.cc/mr/vray_details02.JPG[/img]

[paraganek]

Rerender: yes I am already using vray materials.[/quote]

[studioDIM]

(Otherwise my boss is going to switch our renderfarm to mental ray territory )

I might suggest you tried an interior shot to compare the two engines, if your studio does do any work of the sort.

Also, try animating the camera a bit (a simple motion around the house would do), and check the speed and quality there.

That's what i did with the studio i work in now, to let them get back to VRay 1.47, after they abandoned it for Mr at version 1.09 (ups, i said it!).

I might add that there's no "magic button" for any engine to get quicker renders...
If you posted the scene, someone might attempt an optimisation of it, and you could get some ideas from the differences in the setups.

Regards,
Lele

[paraganek]

Rerender: OK, I have tried Adaptive QMC @ 1 4 but surprisingly in this case it takes almost twice the time to render - 34 minutes

Image rendered with Adaptive QMC @ 1 4, all other setting the same
[img]ftp://visitor:newlands@ftp.newlands.cc/mr/vray03_lr.JPG[/img]
Link to high resolution image: ftp://visitor:newlands@ftp.newlands.cc/mr/vray03.JPG

[paraganek]

StudioDIM:

If you posted the scene, someone might attempt an optimisation of it, and you could get some ideas from the differences in the setups

ok, here are the two scenes if someone wants to play something with

Max 7, Mental Ray, Maps ftp://visitor:newlands@ftp.newlands.cc/mr/test_mr.zip

Max 7, Vray ftp://visitor:newlands@ftp.newlands.cc/mr/test_vray.zip

[studioDIM]

Ace!

[plastic_]

(Otherwise my boss is going to switch our renderfarm to mental ray territory )

where is the logic behind that? for the price of the mr licences you can get additional computers to increase vray speed greatly.
besides, mr is quite unuseable for interiours.

[percydaman]

In exterior scenes, basically all the current versions of all the latest gen renders are gonna be pretty similiar. Like another said, try an interior scene and see how long Mentalray takes.

I know that doesn't answer your question, and unfortunately I dont have time to delve into your scenes and settings. I haven't seen alot of interior scenes from you, so maybe your not going to see the real speed of vray compared to other engines until you do.

[RErender]

I spent some time with your file last night.

To get the same shadow on the facia in v-ray as mr set the bias on your sun to .01

your QMC secondary bounces are set to 50 subs, you can get some speed increase by changing them to 8 without much difference in quality.

Adaptive Sub AA like you had it is quickest for this scene.

The V-ray fill lights you fave in there are slowing it quite a bit, if you must have them atleast set them to "save with imap", Better to get rid of them and check "affect opacity" on your glass material to let skylight in.

With the above changes the vr and mr files rendered in almost the exact same time.

One thing I did not get to but is my standard is to use a vray dome light for skylight, saved with imap with subs up around 100. This allows you to lower the GI settings while getting good detail.

What they have said about interiors is true, it is no contest there.

I noticed you were getting a lot of errors on your displaced objects, setting the UVW to "box" type will fix it.

[GeneCrucean]

(Otherwise my boss is going to switch our renderfarm to mental ray territory )

where is the logic behind that? for the price of the mr licences you can get additional computers to increase vray speed greatly.
besides, mr is quite unuseable for interiours.

Actually Max 8 has unlimited MR rendering nodes. Not the standalone, which means you can't render .mi2 files but through backburner it has unlimited.

[paraganek]

Thank you all guys !
It is a lot of usefull information for me.
I am going to test some interior scenes in MR and we will see how it compares.

Actually Max 8 has unlimited MR rendering nodes

that is exactly the point and because it is included in 3dsmax the studio I work for does not have to pay extra for some other (vray ) plugin

[CCS]

Render time is just one factor. Have you compared the setup time? (creating materials, setting up lights, etc.)

As others have mentioned, try looking at interiors as well.

[studioDIM]

Interiors in Vray basically means "Use the LightCache method for the secondary bounces, and live happily everafter"