Optimal Render Settings - your ideas

[moodflow]

Hi All,

Here are a few questions.  Hopefully we can get some good tips from each other.

What are your favorite render settings and theories?

What is your take on detail, GI, and sky and cloud sample settings?

Which is better for render time (assuming same quality): lower sample settings/quality settings, and higher resolution, OR higher sample settings/quality settings, and lower resolution.  I have been going the second route, but 800x600 image are taking days to render on a 3GHz PC. 

I see people churning out some nice images that are atleast 1024x768 and even larger, and they are quoting rendertimes usually no longer than about 36 hours. 

Lets say you drop sample/quality settings down.  This will drop rendertimes significantly.  Then you UP the resolution to a very high setting.  Then you render the image, then just scale it back down in photoshop to compress the detail and minimize grain.  Would this be better than just sticking with higher sample/quality settings, and smaller resolutions?  I guess only a real-world test will tell.  This would be valueable information since we could ride the line between under and overkill on settings.

[ProjectX]

For an average image, one that doesn't use much close-up shadow, and doesn't have fancy lighting (sunset, night, or dawn) I use Oshyan's fill lighting and GI of 0/0. this is especially useful if you have don't have much colour in your scene because the fill lights add more of a blue than normal GI.

If I do use GI I never go above 3/3.

For detail I never go higher than 0.8, as i've not noticed any real difference after that stage, AA I keep at 3, because it doesn't really slow down my render that much. For test renders I render at 640x480 at 0.5 detail level, usually taking around 1/2 an hour. My final images are 800x600 (I'm using the unregistered version at the moment).

Cloud samples I always use the max settings, and usually have atmosphere set to 128 samples, but then I render overnight and I find I save more time by using higher settings than having to re-render because of graininess.

Average render time for me is usually around 8 hours, unless I've got a lot of nodes used. I have yet to complete a render with the soft shadows work-around.

As far as I've heard, increasing resolution has an exponential effect on render times, so you would probably be better off rendering at your target resolution with higher detail settings, although I don't know to what degree increasing detail settings has on render times.

My settings are usually overkill to ensure I don't have to re-render. My final render laptop is 1 gHz single-core, with 512Mb RAM. My test-render PC is 2.4gHz Dual Core (so I only get 2.4 used until T2 supports dual-core) with 4 gig of RAM.

[rcallicotte]

Test Renders:

640X480
.4 - Detail
1 or 2 for GI Detail and Quality
Surface Detail depends on the scene, whether I'm close to a surface that matters to me or not


Final Renders:
Above 1000 X 1000
.75 - Detail (rarely higher)
2 for GI Detail and Quality
Surface Detail is the same as the Test Render

I sometimes change the contrast or gamma settings under the Render Effects tab (to taste).

Sky settings are anywhere from 32 to 64.  Cloud settings are 64 for cirrus as long as there are other clouds and 128 or higher for cumulus.  I always change the atmosphere settings to lower haze as much as I can without eliminating it entirely.

[moodflow]

ProjectX,

Thanks for your input.

I have a very similar setup, but my rendertimes, are DAYS for a simple 800x600 render.  

I've tried this on 4 separate PCs, with the same results.  Its likely some settings I am using.  I've been keeping atmospheric settings at 128, and cloud settings 128 to 512, depending upon needs.  Otherwise I see grain.  This is likely whats bringing it over.

I did some tests on GI, and found that anything over 4/4 is unnoticeable, and rendertimes jump exponentially.  I am likely going to stick with 2/2 or maybe 3/3 as you do.  I haven't noticed much of a difference with increasing AA (AA will eventually be killed once standard resolutions increase past a certain point, for PCs/games anyway).

[rcallicotte]

As we get new updates, all of this data will change for me.  I'm assuming as things work more like the designers prefer, the settings will be more and more astute while our render times will be better and better (over time).

[ProjectX]

ProjectX,

Thanks for your input.

I have a very similar setup, but my rendertimes, are DAYS for a simple 800x600 render.  

I've tried this on 4 separate PCs, with the same results.  Its likely some settings I am using.  I've been keeping atmospheric settings at 128, and cloud settings 128 to 512, depending upon needs.  Otherwise I see grain.  This is likely whats bringing it over.

I did some tests on GI, and found that anything over 4/4 is unnoticeable, and rendertimes jump exponentially.  I am likely going to stick with 2/2 or maybe 3/3 as you do.  I haven't noticed much of a difference with increasing AA (AA will eventually be killed once standard resolutions increase past a certain point, for PCs/games anyway).

Upload a simple-ish tgd that you've rendered, and post the render times, then I'll try it on my laptop and see what I get. That way we can tell whether it's the settings or just the setups. I'll also have a look at the quality settings, see if I can find anything that strikes me as excessive.

[rcallicotte]

I can try the TGD as well as long as I'm not doing anything prohibitive.

I forgot to mention AA.  I did use 3 as the standard, but I've shifted to 4 to see what I can do differently with that.  Haven't noticed a big hit in time because of this, though.

[Volker Harun]

Test renders:
600x400, quality 0.4 - cropped renders 0.8
AA 3, GI 0|0 to max 1|1
cloud samples are fun

Full renders:
at least 900x600, quality max. 0.8
AA 3, GI max 2|1
cloud samples become less funny ,-)

Lighting - just as it is needed.

[FrankB]

I think there's no such thing as the optimal render settings. Sorry guys, but this is really too complex to say.

If I'd guess - before my average final image, I make about 50 test and crop renders. By the time I've done them, I usually know exactly which render settings I need for the final scene.

But apart from that, too many factors determine the right render settings. Take GI, for example. The average daylight scene usually is good with 1/1. Scenes at dawn or in great shadows may benefit from 3/3.
Atmosphere is next. Sun behind you, a default atmosphere, and you don't need to do a thing. Should you have a thin cloud layer and want to have trees cast shadows on that fog, you can pump atmo samples up to 100 - easily.

But if you're really, thoroughly work on making an image detailed and intresting, you'll have figured out the right render settings well before you launch the final render - I'd say ;-)

Cheers,
Frank

[Volker Harun]

Another point I mentioned in another thread is the impressionistic thought ,-)

If you have in every single corner high definition, the brain is going to get bored very quickly. As an example I told that a preview is just dreamy, while the finished rendered scene is boring.
The point is that your fantasy, your imagination has the ability to add the missing information. This process is creative perception and far more interesting than highest detail.

Volker

[moodflow]

Thanks Frank and Volker... definitely "outside" thinking here.

[bigben]

Frank has a good point.

With GI you can also play around with the enviro light settings to alter things differently and achieve far more than just filling shadows.
<http://forums.planetside.co.uk/index.php?topic=1851.0>


GI detail is more like an intensity setting. Shadows tend to get lighter with higher settings, but a higher setting doesn't necessarily mean better.

GI quality affects the quality and (as a result) the apparent level of detail visible in the shadows.. higher is better, but you have to be close enough to notice the difference.

What you set either of these GI settings to will partly depend on how much shadow detail is up close to the camera, and then how much you want to "fill" the shadows. You can also combine GI with fill light(s), allowing you to reduce GI detail in many situations.

Increasing render size is, in a way, increasing the detail setting because TG has to interpolate the fractals to calculate the extra pixels, but that is not necssarily the same as increasing the detail.  Try it yourself on 3D cirrus clouds and cliffs with fractal displacements as two examples that spring to mind. From there, it's a compromise between quality and time. Cropped render tests are the quickest way to decide as Frank suggested.

[Oshyan]

Generally speaking increased detail should be the best way to get a good image as opposed to rendering at higher resolution and lower detail and then downsampling. The trick is finding the right detail settings which are the "sweet spot" between detail/quality and render time. Only experience can give you a decent idea of this and even then it is very scene/situation-dependent.

Moodflow, in regards to your very long render times, I suspect it is either that you tend to do challenging scenes (very dramatic lighting, lots of rays) which demand high cloud/atmosphere samples, or you have very sensitive vision for noise, or you are simply using higher than necessary settings. 128 in the atmosphere should very seldom be necessary unless rays are involved. I can't recall the last time I went above 64, and even that was only for one image a little while ago. Clouds for me tend to stay around 64-128, though I am not often attempting big cumulus, which demand 256 or higher in many cases.

The other thing is that there are a few specific settings which can seriously kill render time just with a little checkbox tick - most notably Ray-traced Shadows in Atmosphere and Clouds. Both of these settings will totally kill render time and interestingly will also have very little effect on most scenes. GI Surface Details is another one.

Ultimately one should take a fairly cautious approach to enabling specific features. I know with TG 0.9 there was a very strong and unfortunate tendency for people to just turn everything up/on with detail options and expect to get a noticeably better picture for it. In most cases it was just wasted render time. This is even more true now in TG2 with many more detail controls and much wider ranges of settings that are possible - it's much easier to do something irrational and end up with ridiculous render times.

That being said there *are* also scenes that TG2 just chokes on right now. Perhaps you are just prone to making this kind of image. We can't know for sure without some examples of images and render times with .tgd's or detailed setting explanations.

- Oshyan

[bigben]

Moodflow, in regards to your very long render times, I suspect it is either that you tend to do challenging scenes (very dramatic lighting, lots of rays) which demand high cloud/atmosphere samples, or you have very sensitive vision for noise, or you are simply using higher than necessary settings. 128 in the atmosphere should very seldom be necessary unless rays are involved. I can't recall the last time I went above 64, and even that was only for one image a little while ago. Clouds for me tend to stay around 64-128, though I am not often attempting big cumulus, which demand 256 or higher in many cases....

My cloud samples generally seem to be much lower than what other people are posting, although that's possibly because I don't render towards the sun much. What I have found with clouds are that the contrast of the cloud fractal, and its smallest scale can often be adjusted (decreased and increased respectively) to reduce noise without changing the cloud too much, particularly at lower render detail settings.

[moodflow]

Thanks Oshyan for your response.  Definitely good to get other's opinions on the matter!