Vray versus Mental Ray Glossy Reflections

[paraganek]

After testing both Mental Ray and Vray engines in an interior scene we have come to a conclusion as Morbid Angel says:
"guys, now we all know that the right amount of photons and fg/lc gi can produce a relatively close render times in both engines, however now try applying some effects to the scene like glossy reflections to the floor for example, use displacement, turn on motion blur or dof....good luck mental ray"

I am using the test scene from my previous MR vs Vray Interior thread.
http://www.chaosgroup.com/forum/phpB...ic.php?t=14092

I have just added glossy reflections to the floor otherwise the scene setup and the GI setup remains the same.

First of all I rendered the scene in MR using DGS material with glossies:

MR render time: 4:40
[img]ftp://visitor:newlands@ftp.newlands.cc/mr/mr_int_glossy02_s.JPG[/img]

Vray render took 8:15
[img]ftp://visitor:newlands@ftp.newlands.cc/mr/vray_int_glossy02_s.JPG[/img]

MR render still has a couple of those nasty light leaks but I believe with the right tweaking those can go off and it is still going to be pretty fast.
As for the vray scene I have tried a couple of different combinations (tweaking refl.gloss.subdivs, switching to adaptive QMC) but anything either took even longer or there was more noise then the MR render has.

If anyone has any suggestions please share.

Both scenes can be downloaded here:
Max7, mental Ray
Max7, Vray

[studioDIM]

lightcache for secondary bounces.
for that size, 500 subdivs and default settings would do.
NO light leaks, and speed! ~8D

Try this

In my experience there's no way to get lightleaks off mentalray, unless you crank FG up to such an extent it becomes unworkable (and the lightleaks would still be there, but smaller...).
But you're welcome to try it for yourself

Lele

[arobbert]

Don't forget to use light cache for glossy rays.

[jujubee]

Don't forget to use light cache for glossy rays.

no, don't do it...

[RErender]

Don't forget to use light cache for glossy rays.

Yep was just going to post that, I did the test with just checking that and got 1min20sec for the v-Ray and 2min15sec for the MR render.

[jujubee]

Yeah - also check your light settings - theres like 10 and some of them have 600 subs when they could be 20! Also you have min samples up to 15 when you can leave it down at 8. Another thing to note- you have mitchell as AA filter - i think that tacks on time also. The MR version does not look like it has good AA applied...

Now try rendering that sucker... I did it in 4 mins with an Athlon 3200 while having the forum open, media player running and another 3d app.

[arobbert]

Don't forget to use light cache for glossy rays.

Why not?

[Morbid Angel]

well lets see what it takes to get mr to get rid of those light leaks.

[studioDIM]

well lets see what it takes to get mr to get rid of those light leaks.

Ditto!

Yeah - also check your light settings - theres like 10 and some of them have 600 subs when they could be 20! Also you have min samples up to 15 when you can leave it down at 8. Another thing to note- you have mitchell as AA filter - i think that tacks on time also. The MR version does not look like it has good AA applied...

It seems you're a bit confused with the VRay settings as to what does what...
Don't forget to check the Vray manual at

http://www.spot3d.com/vray/help/VRay...beta/index.htm

i found it an invaluable resource to learn the ins and outs of VRay...

Well, after this forum, of course

re,
Lele

[jujubee]

It seems you're a bit confused with the VRay settings as to what does what...

Yep I was wrong about the light settings as it effects Photon maps. I think AA does effect render times. The other setting I took down was min samples which were at 15 and took it down to 8 - this probably saved the most time then.

[studioDIM]

misunderstandig jujubee

I meant paraganek was, IF he had those settings for the arealights subdivs.
My mistake entirely as i did not check any of his scenes, but thought you referred to that particular parameter.
Also i remembered from his previous scene some missetting here and there.

I thought 1+1 made 2, but in this case it made 3

Impressive what a misunderstanding can do though :P

Lele

[jujubee]

Well, you 'mistakenly' helped me understand that Light Setting Subdivs only effected Photon Maps which I didn't know before... One less parameter I need ot adjust from now on.

[vlado]

As I posted in the original interior thread, the mental ray setup is wrong. You cannot use photon mapped GI with skylight - you'll have to use additional lights to compensate for the missing lighting.

Best regards,
Vlado