20 gig of ram but 99% physical memory?

[benjaminbogaert]

So i'm trying to render out my grass: Itoo Forestpack pro.

And before I know it my physical memory jumps to 99%

 

So I have read a few things that certain settings can affect your RAM usage, since I'm using 20gig never gave it much thought, until now hehe.

 

So rendering at 4000x2821 px

Also I have an SSD hard drive so its not about defragmenting or anything.

These are my render settings.

 

Never had this problem before, but this is the first time i'm rendering at 4k.

[cg_Butler]

It might be that because your dynamic memory is 0 machines will use as much memory as they need because 0 denotes no top limit. If your file has high RAM usage they must be going over their maximum.

[benjaminbogaert]

Ah yes I changed that back to 18500 which should correspond to my 20gig of ram.

Alot of confusion about that setting, I keep hearing that as of vray 2.0 I should set it to zero. That way it only uses what it needs or something.

 

But are my settings abit right? I have never rendered such a big resolution, and not sure about certain value's.

 

Like lightcache 1600 to little or ? go for 2400?

[cg_Butler]

Setting it to 0 basically takes any limits off. So if your scence needs 50GB of RAM (probably unlikely) then your machine will in theory try and use that much.

 

If you give it a limit then it won't go over them limit for RAM usage, but will start paging your hard drive, which may be very slow.

 

Your settings, in my opinion are a mixed bag. Most are high but your IR is low. You can adjust the scence RAM usage further using the max tree depth, but that is a per scene specific value so i can't help you on that as it might be set to its best value already. I tend not to change that value too much anyway to be honest.

[Scott Schroeder]

The general rule is that the larger your render the lower your settings can go. You are simply giving the buckets more to process with larger image sizes. You could probably turn your light cache down to 800-1000 and not notice a change at all.

[benjaminbogaert]

Sweet thanks, also, does this apply for the DMC settings aswell?

 

Like instead of medium go to low? Thanks for the replies so far

 

To answer Andy: My IR map is from a tutorial from viscorbel, I'm not quite sure how I would change em for the better.

 

Much obliged all.

Edited August 1, 2013 by benjaminbogaert

[Scott Schroeder]

Sweet thanks, also, does this apply for the DMC settings aswell?

 

Like instead of medium go to low? Thanks for the replies so far

 

To answer Andy: My IR map is from a tutorial from viscorbel, I'm not quite sure how I would change em for the better.

 

Much obliged all.

 

Not necessarily on your DMC settings, that rule is usually limited to your GI settings.

 

Though I never use the global subdivs multiplier as that jacks everything up by a factor of 2, even things you don't need any higher. I set my subdivs in the objects I need. There generally is no need to set your min samples above 8. You don't know the true number of samples you are working with so why apply a much higher setting to areas of your scene that really don't need them?

 

You might want to up your adaptive amount to at least .85-.9. If you are not using an HDR map for lighting you can even get away with that at 1 and gain some more speed.

 

You can turn off the anti-aliasing filter as well. With no filter you get an image similar to what Mitchell-nitravelli would give you anyways.

 

I find that DMC set to 1/16 is overkill. I've gotten pretty decent results setting it to 2/5 or 3/6 if you still have some pesky things going on. You really don't see much improvement after 6 except in your render times. As a rule of thumb, I don't set it to 1 as Vray will almost always choose the wrong sampling somewhere in your image, this is due to the color threshhold specified.

 

A lot of good look-up knowledge is in the back of the 3ds Max 2011 One Project Start to Finish book. While it is a bit dated, the science behind the critical Vray settings in there is always good to have handy. You might want to pick that book up, I keep a copy handy at my desk just in case.

[benjaminbogaert]

Wow, now there's some useful info haha. i'm defiantly gonna try some of those settings,

My biggest problem is vegetation, even with using vray proxy's its a real render killer, and if you still want grass to look like grass, it gets so "undefined" quickly,

 

I'l post the results later, again much appreciated!

[notamondayfan]

 

I find that DMC set to 1/16 is overkill. I've gotten pretty decent results setting it to 2/5 or 3/6 if you still have some pesky things going on. You really don't see much improvement after 6 except in your render times. As a rule of thumb, I don't set it to 1 as Vray will almost always choose the wrong sampling somewhere in your image, this is due to the color threshhold specified.

 

I find DMC works best when around 1/20. Sometimes lower settings are slower. I use to render everything at 1/100, as the render times weren't considerably noticeable.

By using 2/5 or 3/6 you are effectively forcing Vray to over compute areas of the image that don't need it. Give vray a range of 1/20 will mean vray will use 1 when it's rendering uncomplicated areas (flat materials, no area shadows, etc) then when it needs to it will go higher.

 

I also very rarely touch the DMC sampler, instead I use the colour threshold (clr thresh) to control noise.

 

Dean

[beestee]

It is a good idea to optimize render settings, but there are a few more items you might also want to consider.

 

The frame buffer stores rendered buckets in RAM until the rendering is complete, then it writes the image in it's entirety to the destination once rendering is complete. The frame buffer can be disabled and free up some RAM during final (high-res) renderings.

 

ChaosGroup also offers the vrimg format:

 

Render to V-Ray raw image file - when this is on, V-Ray directly writes to disk the raw image data as it is being rendered. It does not store any data in the RAM, so this feature is very handy when rendering huge resolutions for preserving memory. If you wish to see what is being rendered, you can turn on the Generate preview setting. You can specify either a .vrimg or an .exr file for output:

• If you specify a .vrimg extension, the resulting file can be viewed through the File > View image... menu of 3ds Max, or converted to an OpenEXR file with the help of the vrimg2exr tool.
  
• If you specify an .exr extension, V-Ray will write out a tiled OpenEXR file that can be used directly by 3ds Max or other compositing applications. The file contains all render elements for the image.

Are you using Windows Vista or later?

 

Ever since the release of Windows Vista, Microsoft has been adding a feature called SuperFetch that caches your most often used programs in the RAM until that RAM is needed for a task or process that the user has specifically requested. It basically makes it so that when you go to open Max or Photoshop, it takes much less time since it anticipates that these apps will probably be opened at some point in your day.

 

This can make it look like all of your RAM is being used constantly, but SuperFetch will in fact free up this memory if it is needed for rendering.

 

There is a way to disable this, which if you have an SSD then the feature is not really necessary...then again, it doesn't really cause any problems when enabled with the exception that it appears that your physical memory is being used up.

[benjaminbogaert]

Very usefull info thanks, my biggest problem is the damn forestpack pro plugin, I would expect it to be "optimized" more.

Mind me asking, generally speaking, an image with a resolution of 4K with a lot of foliage and windows, how much time would this take?

 

I'm running an octa core from amd, 20 gig of ram, SSD, and a geforce gtx 780. It just doesn't seem right I'm looking at renders for about 7-8 hours.

 

I'm gonna keep on tweeking the settings, i'l try some more of these settings, see what I get.

 

As always, much obliged.

Edited August 2, 2013 by benjaminbogaert

[beestee]

If you are using opacity maps for the grass, be sure to turn filtering off. Mesh is preferable to opacity maps with ForestPackPro when possible.

[notamondayfan]

Very usefull info thanks, my biggest problem is the damn forestpack pro plugin, I would expect it to be "optimized" more.

Mind me asking, generally speaking, an image with a resolution of 4K with a lot of foliage and windows, how much time would this take?

 

I'm running an octa core from amd, 20 gig of ram, SSD, and a geforce gtx 780. It just doesn't seem right I'm looking at renders for about 7-8 hours.

 

I'm gonna keep on tweeking the settings, i'l try some more of these settings, see what I get.

 

As always, much obliged.

 

7-8 hours seems OK to me, especially if you're scene is packed with geometry, opacity, glossy reflections, etc.

[benjaminbogaert]

Update, thanks to you guys, I managed to seriously reduce render time, also I used these free trees from Vizpeople made them into proxy's however it seems I checked point cloud or something, which made vray crash constantly, few hours on google told me that.

 

All is well, and now to finalize the scene. i'm looking at a render time of 4 hours, so yay me!

 

As always, Much obliged.