Tree's + Vray Render Time

[amateurviza]

Hi Guys,

 

Long time reader, first time poster...

 

I have a scene where i have roughly 200 trees (3 different types) 100 bushes (1 type) all Archmodels from evermoton.org and the polycount is killing my render times. Its not the material as i am rendering the scene in "material override", and so i was wondering if there's a way to reduce this and speed up render times?

 

How do people overcome this?

 

Thanks

[Krisztian Gulyas]

I don't know which method is the best, never had more than 10-15 trees in a scene but I would try the pro optimizer modifier. It will reduce the polycount but I think the trees will still look good from a distance.

[Ismael]

http://www.evermotion.org/tutorials/show/7857/v-ray-proxy-in-use-

[amateurviza]

Hi,

 

Thanks for the replies, they are already Vrayproxy's and so this aids during the modeling process etc but when it comes to rendering that's when the trouble starts.

 

I'll give pro optimizer a try

 

Cheers

[matthewgriswold]

Since you're dealing with Proxies, give a read about Dynamic Memory Limit under the System tab.

http://www.spot3d.com/vray/help/200R1/render_params_system.htm

 

If you're using 2.0 or later, set it to (0) to give V-Ray full access to as much memory as it needs. This will obviously take some testing+tweaking to ensure your computer won't crash-I've read some people set this number to somewhere around 75% of their system memory.

[cg_Butler]

Also, when you are copying the trees make sure you are Instancing them and not just copying. This will use less RAM. But changing your Dynamic memory is definitely the first thing to try.

 

How much RAM does your computer have?

[John Dollus]

are you sure it is the poly count? Can you post your vray settings as well as what your pre-calc and render times are currently along with your relevant hardware specs?

[SkylineArch]

I have a scene with 103 trees, 63 bushes, 664 plants, and 500,000 grass patch proxies, and 3D Ivy, all rendering at once. it uses about 14GB of RAM when rendering, 1.8 GB used by Max when the scene is open, and renders on my Laptop.

 

It's all about proxies and settings.

 

http://features.cgsociety.org/newgallerycrits/g54/433554/433554_1348058954_large.jpg

[John Dollus]

exactly what I'm getting at as well. Vray chews through polys so I suspect there's something else going on.

[amateurviza]

Hi,

 

@Matt Griswold – Using Vray 2.3 so I’ll definitely give that a go, cheers.

 

@Andy Butler – yep, their all instances, using multiscatter...

 

Granted I'm rendering on a laptop, but also have access to a workstation which is more powerful and still not much difference there (using the same Vray settings).

 

Laptop:

Processor: Intel® core™2 Duo CPU P8600 @ 2.40GHz 2.40GHz

Installed memory (RAM): 4.00 GB

System type: 64-bit Operating System

 

@ John Dollus – Vray settings attached:

 

 

Render times: last night reduced the trees and bushes down to around 20 each; lightcache took around 3 hours I think (went to sleep) and after 8 hours still had at least 3 hours left to render.

 

I should add here that this scene also included grass, modelled the Peter Guthrie way and again scattered as proxies with multiscatter, however when rendered without the trees the times seem normal.

 

Maybe it’s just too much for the laptop?

[amateurviza]

Since posting the above, and after reading:

 

http://www.spot3d.com/vray/help/200R...ams_system.htm - thanks Matt

 

And... http://renderstuff.com/best-vray-settings-raycasting-cg-tutorial/ - Which recommends using 70/80% of your Dynamic Memory limit which for me (having just 4GB on my laptop) is around 1700.

 

I rendered out a scene last night, using roughly 150 trees, 100 bushes and loads of grass proxies, all scattered with multiscatter, and the render time halved!

 

Lightcache went from +3 hours to 55 minutes and render time was around 6.5 hours, so all and all the whole thing took close to 8 hours. A huge improvement!

 

Is this closer to what you might expect?

 

The scene is a contemporary house amongst its setting, so the trees and bushes are the surrounding vegetation that are either in view or in the reflections of the windows.

[matthewgriswold]

Yes, the more RAM you can throw at V-Ray, the better it can perform.

 

Good to hear you're getting things sorted out, though too bad about the 4GB limit...hopefully you'll be able to upgrade in the near future. By the way, 1700 is only 42.5% of 4GB

[cg_Butler]

Looking at your setting for Dynamic memory as they are the defaults, having 400MB limit would mean your machine would use up to that and then start paging the hard drive for the rest of the GBits it needed. Paging can be very slow.

 

Essentially, the more dynamic geometry you have, the higher the limit could be, up to a point which will differ for every scene. It's ovly relevant for dynamic geometry such as proxys, displacement etc. Shame on your 4GB limit though! But at least your were able to quadruple the RAM usage for that particular render. It opened your RAM up for usage and you saw the results so that is great!

[amateurviza]

Ha ha yeah noted, cranked it up to to 3000 and its taking just under 2 hours for a 1920 by 1080 image.

 

Thanks for all the help... this forums a great resource!

[komyali]

I have a scene with 103 trees, 63 bushes, 664 plants, and 500,000 grass patch proxies, and 3D Ivy, all rendering at once. it uses about 14GB of RAM when rendering, 1.8 GB used by Max when the scene is open, and renders on my Laptop.

 

It's all about proxies and settings.

 

http://features.cgsociety.org/newgallerycrits/g54/433554/433554_1348058954_large.jpg

can you please tell me what processor are you using, your settings and time ?

[SkylineArch]

can you please tell me what processor are you using, your settings and time ?

 

The processor is an i7-2720QM, but sorry, I did those back in September, I don't remember the render time.

[komyali]

I have i7 3930K 16 G Ram but never ever think about "103 trees, 63 bushes, 664 plants, and 500,000 grass patch proxies" I am a coward :DDD I am using pictures of trees instead trees and plants less memory and faster renders but I will give a try next time with proxyes