15+ Hour Renders (Max + Vray Renderer 1.5)

[jlpeacock]

Hey,
I'm fairly new to Max and this is the first time I've been required to do any kind of photo realistic scene. I have decided to take vray on as my renderer of choice given it reputation with interior scenes. Unfortunately I've had no previous experience with it and I'm finding I'm banging my head against a brick wall as I keep going round and round in circles following the various contradicting tutorials and tips/tricks.

Skip the intro.. Whats the problem:
For a relatively simple scene I've render times of 15+ hours per frame and simply wondered if individuals maybe able to suggest some adjustments to my current settings.

System:
Duo Quad Q6600 2.4GHz
4GB 800Mhz RAM
1TB RAID 0 Storage
NVIDIA 8800GTX 756MB RAM

Below you can see my "shop scene". Although I've some experience modelling, I'd still count myself as being relatively new to Max. I've often come across very complex scenes with very low polygon counts, so I presume my first problem is the amount of polygons in my scene?

Polygon Count: 1,112,024
Verts: 701,697


Below are the current render settings I'm using picked and modified from a number of sources:
http://www.aversis.be/tutorials/vray/index.htm
http://www.evermotion.org/tutorials/mich/
http://www.vray.us/vray_tutorials/re...tutorial.shtml

Resolution 1191x842 (A3 @ 72dpi)
Saving in a JPEG format

I found that the only way my scene was sufficiently illuminated was through using the light cache as secondary bounce instead of the Quasi-Monti Carlo



Things such as Vray Caustics etc that I've not included are disabled/in their default state

Now as far as materials go, I've dropped down all the sub division back down to their default 8 after experimenting with them at 50 for glass and chrome. I've also put the max depth back to 5 having experimented with it at 10 for glass (172 Hour Render Estimate).



Glass table top is a VrayBlendMtl, which uses a glass and a frosted glass material to create the etched logo you can see in the image below (This render also shows an issue I'm having with the glass material not allowing lighting through properly. Ive made sure affect shadow and alpha have been enabled) [unsure why I used a BlendMtl, but think it was because I couldn't use a mix]



I've used 4 lights:
1x vray spread across the roof enclosed within a hollow box, which shines through a number of light fittings (seen in the first image above).
2x vray lights in the fitting rooms to further illuminate the rooms and cast appropriate shadows.
1x direct light to act as a sun with vray shadows enabled.



I've left their diffuse sub div at their default 120 in the render light settings.

You can see an overview of the shop, which still needs work here:



If your able to help and would like me to send you over my scene please PM me.

Any help would be greatly greatly! appreciated.
Thanks in advance.

EDIT: Download the scene here: http://download.yousendit.com/F8658B4636CA41D7

[le1setreter]

very nice detailed description and nice render. im a little bit experiences in vray but for sure no pro...

i think you´re right that render times could be reduzed and i also would like to find out how because rendertimes mostly is a problem...

just a quick question: do you plan on rendering an animation or just a still?



i think i would start with reduzing "Noise treshold", "Min samples" and "Global subdivs multiplier" in the "rQMC Sampler" and from there move on.

Maybe i would test if "Adaptive subdivision" is really longer or not.

Your Materials looks ok for me on first sight and also the lights.

Normally i pick myself a special corner or make special cameras just for little and fast testing on rendertimes and quality.


i hope this helps you a little bit. i also hope that some really experienced with vray will also reply and help (and dont tell im all wrong ).


and yes i would like to give it a try so i can do some tests tomorrow when im back in company. ... and trust me i wont use your work for private or commercial use.

i will pm you.

Good luck and have fun.

[jlpeacock]

Originally Posted by le1setreter

just a quick question: do you plan on rendering an animation or just a still?

Luckily a still, but I'll be rendering about 5-8 of them.

Originally Posted by le1setreter

i think i would start with reduzing "Noise treshold", "Min samples" and "Global subdivs multiplier" in the "rQMC Sampler" and from there move on.

I spent a fair amount of time trying to balance out smoothness of shadows with rendering times.. obviously the render time won that battle though.

Originally Posted by le1setreter

Maybe i would test if "Adaptive subdivision" is really longer or not.

I'll give that a look once i get back home.

Originally Posted by le1setreter

Your Materials looks ok for me on first sight and also the lights.

I had thought I'd resolved my problem with light getting through the glass table top, but now i'm not so sure.. just waiting for my render to check and see. I've got affect shadow and alpha enabled in the material options.. Any ideas what else I could try?

Originally Posted by le1setreter

and yes i would like to give it a try so i can do some tests tomorrow when im back in company. ... and trust me i wont use your work for private or commercial use.

I don't mind if you do, but can't imagine I've done that good of a job being that it's my first real attempt.

[Honki]

Could you post a screenshot with the entire Glass material settings rolled out (refract interp. etc.)?
It's always an issue with scenes containing glass.

One thing I could suggest, if you do want to know for sure if it's the glass causing the problem, is do a test render, with all glass objects' materials replaced with a simple material. Then compare your render times.

[jlpeacock]

Originally Posted by Honki

Could you ...

I'll do it as soon as I get in mate. Or you can take a look for yourself http://download.yousendit.com/F8658B4636CA41D7

[Honki]

Can't open it matey, I'm using Max 8.
Let us know your mat settings later.
I'll see if we can't sort it out for you.

[jlpeacock]

Originally Posted by Honki

Can't open it matey, I'm using Max 8.
Let us know your mat settings later.
I'll see if we can't sort it out for you.

Your a star mate

[le1setreter]

ok i did some screenies of the materials.

i can open your file with max9 and hope it makes no difference. as said will try to test tomorrow.

jason, you mind uploading also your textures to test. if you want to do a fast collection try the "Ressource Collector" in the utilities tab (under more). this utility let you export all bitmaps and if you like also the max file into a special folder.

honki is right with the test without the glas mat. and yes tabletop looks a bit ... overdone.

[Honki]

Hmmmm that's tricky. Can't see anything really abnormal there.
The only thing that I can see being a potential problem, is the desk glass, and the glass of the light-shade. I know that my computer chokes up when I start adding glossy refractions.

Looking at your scene though, and the way it's set up, I'd have imagined the second render (outside the shop looking in) would have take the most time, as the render engine basically has to refract everything that's behing that glass.

Try what I suggested before, and change your glass objects in your first render to a flat material. See if things improve.

[jlpeacock]

Thanks for the replies guys. Really appreciate it.
Sorry it's taken so long to get back to you. I've had a busy few days..

Thanks for sorting the material shots out for me le1setreter. You can download my completed scene with materials here:
http://download.yousendit.com/A07660D15CA6F0DA

Cheers
Jason

[jlpeacock]

Originally Posted by Honki

Looking at your scene though, and the way it's set up, I'd have imagined the second render (outside the shop looking in) would have take the most time, as the render engine basically has to refract everything that's behing that glass.

I had a concern that a lot of render time was wasted on the glass front, so I have since removed it and left the frame.

[Honki]

The long render is this one...
http://img142.imageshack.us/img142/7092/92220270jc8.jpg
The only glass I can see is the desk and lightshade.

I reckon it's the desk.

[le1setreter]

jason, i will try your new files these days. but i think Honki is right. did you make a test-render with all glass amterials replaced? like i said before your "Table Top"-Material looks very "heavy".

[Leonidas]

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Please visit

http://forums.3dtotal.com/showthread.php?t=57755

I really need help bout this.Please Please Please

[jlpeacock]

Well I played around with the settings for quite sometime now and managed to get everything but the glass to look how I wanted within a reasonable render time.



I'm currently rendering out my image with the global multiplier set to 8 as I've found its the only thing that works, but unfortunately throws my render times up somewhat.

How can I improve the quality of the glass without effecting the other elements?

Ive tried:
1.setting the glass refract/reflect subdiv to a value of 300 going on the principle that the global sub div would have multiplied this value
2.enabling interpolation and playing around with those settings.
3.increasing the number of shadow subdiv the light has
4.increasing light cache to a value of say 2500
5.changing the glass so that it is simply plain and not frosted etched glass
6.setting the sampler noise threshold down to 0.001
7.switching the filter modes mitchell.. area.. etc
8.setting the adapive subdiv min 8 max 8
9.setting the samber min samples to 16.. 32

giving me a headache!

I'm using low irradi preset as I've notice no boost in quality/realism using the med/high..