I mentioned this a way back but I still feel it is an important issue and I am trying to understand it better. I positively LOVE the Terragen system and the atmospheric effects are simply the best bar none. My only criticism about TG is that in every render I have seen to date, the foreground contrast is always way too high...the dark areas inside plants, the shadow sides of rocks, anything where direct light does not fall, the ambient fill light drops off too quickly and goes almost black resulting in almost total loss of detail in those regions. Is this due to a limitation in TG or is it that everyone is not taking full use of photon bounces (or the equivalent method TG2 uses) possibly due to the resulting huge time needed to do the render? The latter case is certainly understandable...it would not represent a limitation of TG2...the math is what it is. If this case is correct, it would just be the old problem of never having the CPU power to do what you would like to do in a reasonable amount of time.
You could use one or two fill lights...
That could work, and if TG is anything like standard photography, reflectors and lamps would be used for fill light to cut down on contrast. But even "quick" photography w/o artificial fill, has better response in dark areas. Can TG2 overcome this with simply more photon bounces at the expense of longer render times?
Of course you can use higher GI settings ... The first thing you rather want to do is to play with atmospheres.
The original settings of TG2 are almost like 10am in the Sahara desert ... photographies there would have very harsh shadows, too.
A slight overcast sky ... add a cirrus layer, give it a Cloud depth of 40 to 60 and set the Coverage adjust to i.e. 2.
This darkens the overall scene, increasing the exposure inside the camera will give lighter shadows overall.
Adding fog or playing with the atmosphere will give an overall glow, that lightens up shadows, too.
In my case it´s at least partly a question of rendertimes,
because my PC is old and I can´t sleep whyle it runs.
my experience concerning tg-shadows is the following:
The lower the gi settings, the less light and detail in the shadows, but that setting adds heavily to rendertime.
"cheaper" is the "enviro light" .
In this example I increased its strength to only about 1.7 (instead of 1 default) , and what you see here is even slightly contrast-enhanced in Photoshop:
http://forums.planetside.co.uk/index.php?topic=10833.0
I think there is quite a lot of light and detail in these shadows.
One last point concerns flatscreens, I just recently got one, and now all images I made before seem to dark in the shadows.
So I think there must be ways to get proper shadows in TG, if your cpu is just a bit faster than mine.
Best regards,
Jan
Also, camera exposure and envirolight strengths can be adjusted independently of the final GI quality settings.
A luminous, or reflector setup, like you mention, also does well at bouncing and brightening up shadow areas without needing to add lots of GI detail calculation time, I think you can easily get a good balance of detail over render time by just taking those extra couple of steps before hitting the render button. http://sites.google.com/site/d4nd310/tg2gi
Three things:
Higher GI settings (relitive detail is more important than quality)
Fill lights (take a look at oshyan's Fill Light (http://forums.planetside.co.uk/index.php?topic=580.0) tgc).
Up the camera exposure.
Save the render as an EXR and play with the levles in post.
Ok four things :)
Richard
Thanks everybody for your responses. Great work too!
So my original assumption was correct then...GI for absolute realism but at the expense of render time, and also artificial fill lights to "Stand in" for GI and cut the render times down. I'll have to go back to some of my earlier demos and experiment with GI and just let it run for a few days to see what happens.
regardless of all the tips to circumvent the "black shadow" tendency in TG2, I too think that the default effect of GI seems to be way too low compared to nature - especially the fall-off with distance seems slightly but notably too strong. Just subjectively, though, but still...
I think so, too, but the only other option is to default it to a higher GI level which means a lot slower render times for people just starting out with the program (or for ANYBODY with a relatively slow machine). What I would give for one of those new 12-cores in a small 3-4 machine render farm!
Quote...default effect of GI seems to be way too low compared to nature...
Agreed.
QuoteI think so, too, but the only other option is to default it to a higher GI level which means a lot slower render times
Adding/reducing envirolight strengths doesn't really add to the render time and is the best way to brighten the GI up. What does add render time is higher GI settings in the renderer node because it makes the calculation more correct with higher settings. You can brighten up the GI effect by raising 'strength on surfaces/atmosphere', this way, you can have significantly brighter GI in your scene without adding to the final quality settings.
I'll try that out next. I am running an over the top GI of "6" test right now in my TG2 Demo program. I'll then run it again with your suggestion and make a comparison.
Thank you for the tip.
Try setting GI strength higher in light settings (not in render settings). Eventually, export image as .exr and adjust curves in Photoshop or GIMP.
I've been trying something else recently. Not fill lights but two (or more) Sun lights in the same place. One is set to use soft shadows (soft shadow diameter =50), the other is set to no soft shadow or a very small one (say 1). Sunlight strength is of course halved so that the two combined suns give out the same amount of light as normal. Results look interesting so far but I think it will be scene specific.
I'll post a pic if I come up with anything worthy :)
Richard
Some people also prefer to use two environmental lights - one GI with strength at 1 and one with AI with strength at 0.5 to lighten up the shadows. However, this method increases render times a little.
Quote from: PorcupineFloyd on October 05, 2010, 06:37:57 AM
Some people also prefer to use two environmental lights - one GI with strength at 1 and one with AI with strength at 0.5 to lighten up the shadows. However, this method increases render times a little.
This seems to be fun :) On some test renders I could not notice significant longer rendertimes ... but I am verifying this right now with high quality settings.
EDIT: Okay, the GI prepass takes twice as long, which can be a hazard :( Else, the use of some more colours for ambient light is wonderful :)
I have 3 fill light suns enabled by default at 0.1 strength as well as the envirolight, it helps a lot to brighten things up.
Also, disabling 'strength in atmosphere' will give you fantastic speed increase even at extremely high GI settings. If you like, enable an ambient occlusion to work in the atmosphere and a GI to work on surfaces. These all improve on the default envirolight render times and lets you crank the final GI quality settings really high with no major increase in render time, in fact, it should be much, much quicker, certainly is for me.
Quote from: dandelO on October 05, 2010, 08:07:44 AM
If you like, enable an ambient occlusion to work in the atmosphere and a GI to work on surfaces.
Now that IS a good idea :)
Trying it out now :)
Richard
Well I'm definitely going to try all of this. I'll eventually post a comparisons image here soon.
Okay,
I really like dandelO's idea and it really has some capacities ... but ... ,-) ... it will take me some time to get perfect settings for the atmospheres ...
The comparison-image attached has no fill lights or extraordinary strength settings on the environmental lights. The ambient shadows are produced by the atmospheres.
And for this, the lighting of GI-only has some advantages, the overall lighting on fog and surface shows more details ... as said above, I did not use fill lights, thus this is not a full test.
Nonetheless ... the GI-Pass is with dandelO's setup twice as fast ... thanks dude!
Cheers,
Volker
EDIT: Attached Scene-File
I always make the ambient occlusion white, I really don't like the default blue tint it has. I do think the GI one looks better, obviously but, when you're rendering a scene - you're never going to render a full GI one, at twice the render-cost, just to show back-to-back with the original, simply for comparisons. No one would likely ever notice if you posted an image and didn't tell them there's no GI in the atmosphere. At least, no one has ever asked me when I've posted. ;)
Now, try a scene with very little atmospheric needs(indoor scenes, close-ups etc.), do the atmo disabled GI trick and freak yourself out for a second, by typing 4/4 into the final GI settings. Hit render.
In a thread here before, I was really confused about why I was easily reaching GI RELATIVE DETAILS OF 12! Until, I realised, to my shame, that I had 'render atmosphere' unchecked in my planet node! :-[
I've exploited it ever since! ;)
Popping an edited AO into the atmosphere(maybe up to 0.5 strength, as it's quite strong) in scenes that require it does a fine job of bulking up the atmo' light in open scenes when you need to, if render times and computer power are an issue, like they are with me.
Quote from: dandelO on October 05, 2010, 05:31:50 PM
No one would likely ever notice if you posted an image and didn't tell them there's no GI in the atmosphere. At least, no one has ever asked me when I've posted. ;)
I just dropped off the chair laughing .... :D ;D Thanks for cheering me up ;)
Quote from: dandelO on October 05, 2010, 05:31:50 PM
Now, try a scene with very little atmospheric needs(indoor scenes, close-ups etc.), do the atmo disabled GI trick and freak yourself out for a second, by typing 4/4 into the final GI settings. Hit render.
I did it ,-) I did it!!! I did it :) :D You are lucky that I am too old for doing this 'Jump through the screen'-stuff! ,-)
dandelO ~ you are a *kin genius ;)
Richard
Damn! I want to try out all this cool stuff, but the power surged TWICE and I lost both tests...my UPS can't handle the 750W power supply. So looks like I am going to have to fork out about $175.00 for a new UPS before I try anything again...it's such a drag losing everything twice and I am not going to let it happen a third time, before I start testing again.
Was in the middle of running a test and it dawned on me, too, that trees and bushes have another attribute that helps with fill light...SSS. That would significantly add to fill light, but boost the render time up too.
I did this set of tests to nail down what is needed to get sufficient fill light into shadow areas. dandelO did essentially the same thing in the post, "http://sites.google.com/site/d4nd310/tg2gi". The reason I did this set of tests was to do basically the same thing but in a "real world" setup with natural textures and environment. There was a suggestion to use higher values of enviro Light to fill in shadow areas with more light. In my opinion, this is a kludge which does only one thing...fill in the shadows with light but at the expense of blowing out (overexposing) the light areas in the image you do not want affected. It also does not allow for the physical effect whereby fill light basically comes from the opposite direction to that of the main light source.
The image is too large to post directly so here is a link to Photobucket:
http://s391.photobucket.com/albums/oo359/treddie_bucket/?action=view¤t=Composite.jpg
Or for a higher res version at Megashares:
http://d01.megashares.com/dl/2235584/Composite.jpg
In image 1 (reading left to right, top to bottom), GI is shut off completely, and clearly, no fill light enters into the shadow areas, except for what level of Enviro Light is available.
In image 2, GI was set to its minimum values with Enviro Light set arbitrarily high to show that indeed all Enviro Light does is essentially set the exposure of the image. I know this is an over simplification of Enviro Light, but essentially it has that effect.
In all the other images, I therefore locked Enviro Light to the same set of values, while increasing GI levels. I toggled the "GI Surface Details" checkbox for each GI setup for a pair of side-by-side images with GISD on and off.
Also in each image is the render time. All in all, it looks like fairly decent light fill occurs at any GI settings other than zero. And the higher you go, the higher the fill realism but at the expense of significantly higher render times. It appeared that going with GI of roughly 2, 2, 2 to maybe something like 4, 4, 4 gave more than adequate fill with relatively short render times. In terms of the tight spaces inside bushes, trees etc., I did not have time to check what GI levels would be necessary to reach into those depths. But I am convinced from these tests that mid to high levels of GI are necessary to get sufficient light into tight shadow spaces, and that no cheat can really achieve the necessary effect.
In short, all renderers that use some form of global illumination all have the same inescapable problem...true realism takes a long time to render on even today's 8 and 12 thread machines with more than adequate RAM.
For me, it is worth it.
The outcome of lighting not only depends on rendersettings, maybe that's even not that important as many think.
The essence of good lighting and good "fill" of the GI is the atmosphere settings. The density of the haze and blue-sky together with the glow settings are key to how GI will interact with the surfaces and colour in your scene.
Here's an example to illustrate:
(http://th07.deviantart.net/fs70/PRE/f/2010/228/a/b/Overcast_Weather__V2_by_Tangled_Universe.jpg)
This image does not use a fill light, nor any other special tricks. The settings in the Enviro-Light are default.
The settings in the rendertab for GI were 2/4/8 with ss-prepass.
The trick is that the atmosphere takes care of the fill lighting here. The haze density and exponential height is increased here, as well as some tweaking to the glow settings. The effect is similar to overcast clouds where the light will be scattered throughout the clouds which results in a more flatter type of lighting.
The atmosphere-node has a couple of settings called "primary, secondary etc."
Primary basically means that you will see the atmosphere itself.
Secondary basically means that you will only see the effect of the atmosphere, like haze glow etc.
The fun thing with this that you can use 2 atmosphere-types together.
Let's say that the overcast atmosphere which fills shadows very well is "Atmosphere A" and the atmosphere of your own scene which has the desired colours/appearance, but not the good fill of shadows, is "Atmosphere B", then:
1) Disable "primary" for the Atmosphere A, this will make Atmosphere A invisible, but not it's contribution to lighting.
2) Disable "secondary" for the Atmosphere B, this will disable it's contribution to lighting, but will retain atmosphere visibility.
3) Now Atmosphere A will fill the shadows for you.
4) Atmosphere B will determine how the sky itself looks.
5) The strength of Atmosphere A can be determined by adjusting the haze settings.
This way you can incorporate a good fill lighting into every scene, without adding extra lights, tweaking GI, or rendering at very high settings (GI > 2/2/8).
Tricky is the balance between the two, since it might give unnatural looking lighting in the shadows, since they kind of mis-match with the expected lighting from the visible atmosphere.
I'll see if I can make a setup for this and put it in the file-sharing section.
Cheers,
Martin
This double atmosphere trick is awesome. I am working on a project now which could really benefit from this. Thanks Martin!
Quote from: njeneb on November 03, 2010, 08:01:22 AM
This double atmosphere trick is awesome. I am working on a project now which could really benefit from this. Thanks Martin!
You're welcome Henry.
It has been up my sleeve for quite some time already, but unfortunately haven't made any time yet to document and share it here.
The documentation is kind of finished now with my previous post, so the clip-file will be on its way soon ;D
So please post your results (with .tgd perhaps) :)
Martin
The speed of my rendering... You'll probably have the docs ready first. I may have something by Saturday.
That's great advice Martin. I only wish I could use it like you do! :D I often use double atmos, like you say but still, GI in those atmos is never practical for me...
It kind of defeats my purpose of messing about with secondary lighting. My only reason for doing this is to conserve on render times, since GI takes up very much of that time, I look for solutions of getting around that, as I use a pretty poor machine for rendering(2x2ghz). I tend not to exacerbate GI calculations in rendering, which is what adding multiple atmos would do to me when rendering with GI.
If I could, I'd use GI consistently but I have to cut corners. So, messing around with other lighting solutions seems to be my only option, for now.
Of course, if computer power and render times are not of any consequence to you, as they are to me, you'll get great results using GI consistently, and by using TU's techniques up there. ^^ Go for it! :)
I see your point Martin, although I really think you over-estimate the added rendertime by having two atmospheres in the type of setup I described.
I would have to do decent benchmarks to verify this, but I think I can safely say that it will at most add ~20% rendertime.
An advantage is that in many scenes, without dense vegetation for example, a GI setting of 1/1/8 will be sufficient.
So if only 20% extra rendertime is required, it still would be faster than upping the GI settings by 1.
Everybody should realize of course that this should all be evaluated for every single scene. I mean lighting, GI, rendersettings etc.
So even with my method above there's no absolute golden standard which will always give the best results.
Tangled-Universe > That is an awesome image you posted and I can see your points, and I want to experiment with your ideas. But in that very image...the trunk and branches of the big tree in the back have essentially gone to black with no detail *at least from what I can see in the small image). This simply would not happen in reality. That is why I keep pushing the importance of at least mid-range GI (which you used) but in the case of that tree, I think it begs for more, despite a higher rendering time.
Aye, I get that, Martin. Still, GI in atmosphere takes aprox' double the time to calculate over an edited lighting setup that I would use.
When a basic GI pass takes so long for me, adding secondary atmos will not make it any quicker, if you see what I mean.
This is just my experience, of course. I'm not down-playing your techniques by any means. Everyone can see your lighting solutions are always superb when you render! I'm just a humble cost-cutter. :)
Oh! For a new computer! :D
Cheers, man!
* Treddie: I can see all the detail in the tree you mention in TU's scene, there are no blacked out areas for me viewing it here, it looks lovely, as I posted to Martin on another site where he posted the full size image. It's a beautiful lighting setup he has used.
Quote from: treddie on November 03, 2010, 02:38:54 PM
Tangled-Universe > That is an awesome image you posted and I can see your points, and I want to experiment with your ideas. But in that very image...the trunk and branches of the big tree in the back have essentially gone to black with no detail *at least from what I can see in the small image). This simply would not happen in reality. That is why I keep pushing the importance of at least mid-range GI (which you used) but in the case of that tree, I think it begs for more, despite a higher rendering time.
I cropped the image using html code to make the post more readable. Here you can find the full-res:
http://fc02.deviantart.net/fs70/f/2010/228/a/b/Overcast_Weather__V2_by_Tangled_Universe.jpg (http://fc02.deviantart.net/fs70/f/2010/228/a/b/Overcast_Weather__V2_by_Tangled_Universe.jpg)
As you can see the drop-off isn't that bad at all.
You won't get this much GI/light when using "conventional" tweaking of the GI settings.
Even with GI settings at 4/4/8 or higher you will not get that result.
The numbers of GI-bounces TG2 utilizes is just too limited, so you need to help TG2 a bit by adding lots of diffuse light.
Quote from: dandelO on November 03, 2010, 02:53:05 PM
Aye, I get that, Martin. Still, GI in atmosphere takes aprox' double the time to calculate over an edited lighting setup that I would use.
When a basic GI pass takes so long for me, adding secondary atmos will not make it any quicker, if you see what I mean.
This is just my experience, of course. I'm not down-playing your techniques by any means. Everyone can see your lighting solutions are always superb when you render! I'm just a humble cost-cutter. :)
Oh! For a new computer! :D
Cheers, man!
* Treddie: I can see all the detail in the tree you mention in TU's scene, there are no blacked out areas for me viewing it here, it looks lovely, as I posted to Martin on another site where he posted the full size image. It's a beautiful lighting setup he has used.
Oh this is good discussion Martin :) Sharing ideas and solutions is what we all love here, at least we do for sure :)
Here's a comparison which I made very quickly (see below).
1) = default atmo only @ 17s
2) = default atmo + overcast atmo (no disabling of any rays) @ 26s
3) = default atmo + overcast atmo with primary disabled @ 19s
4) = default atmo with secondary disabled + overcast atmo with primary disabled @ 17s
As you can see the added rendertime isn't much at all. Perhaps not very scientific in regard to render-resolution and detail, but you can see that it renders relatively very fast compared to having 2 fully functional atmosphere-nodes at one time (2 vs the rest). So in a more serious situation you will not have to expect a huge increase.
Second, if you look carefully, you'll see that with 2 fully functional atmosphere nodes there's a lot more noise. So what you can basically conclude is that the number of samples required for a clean result is determined by the primary rays (compare 2 with 3 + 4).
So you could conclude that it is also render-inexpensive.
Tangled-Universe > That image is killer. It's fun to move around and check out all the little spaces.
But I think the big tree trunk though is just too much of a silhouette still. Everything else has great fill in the shadow areas. Compositionally I like it because it makes the tree the first read, and your eye moves on from there. But in terms of how light behaves, if GI can't get in there, what would you do? Put a big reflector in there that is not visible to the camera, so that you can affect that region only, without disturbing everything else?
Good comparison chart, Martin!
I think that No.4 looks so much better than TG defaults, and for the same render time, that's great.
People should really exploit these settings, I know I do. Remember, you are not limited to one atmosphere node/lighting solution/planet/etc. Mixing and matching multiple nodes is a great way to combine many different aspects of light and atmospheric effects. The 'primary/secondary' checkboxes in your atmospheric shaders are your friend and a really cool tool to use for scene effects. Maybe you like the rays that a certain atmosphere node creates but you hate the sky/haze colours, no problem! Enable only primary in your 'sky colour atmo' and only secondary in your 'effects atmo' and you can mix and match both. The combinations are endless. Experiment!
Great thread, with lots of hidden gems, once again! :)
Quote from: treddie on November 03, 2010, 07:23:56 PM
Tangled-Universe > That image is killer. It's fun to move around and check out all the little spaces.
But I think the big tree trunk though is just too much of a silhouette still. Everything else has great fill in the shadow areas. Compositionally I like it because it makes the tree the first read, and your eye moves on from there. But in terms of how light behaves, if GI can't get in there, what would you do? Put a big reflector in there that is not visible to the camera, so that you can affect that region only, without disturbing everything else?
Well technically there should be some silhouetting, still, because the sun is positioned behind the tree just at the left outside the image.
But regardless that I think you expect way too much. This is TG2 and not Vray, Maxwell or whatever :)
The GI and all the tricks available here is very suitable for procedural displacements.
The rendering of objects is not equally developed in that regard.
This is the trade-off in the engine I think. Vray, Maxwell and the other raytraced renderers available are 100% sure not able to do what TG2 does.
What they can do though, is render objects beautifully and accurately (user-dependant of course), something TG2 is less well at.
So if you're looking for a way to get the result you're after then I think I will have to disappoint you?
Martin
Oh, not necessarily. Just trying to push TG2 to its limits. I've done a lot of experimenting with Maxwell and it is a fine renderer, but like you say it's just a renderer. I feel that if TG2 is behind in that respect it isn't by much. One thing is for sure...realism is expensive both financially and work-flow wise. If you rely heavily on refractive materials, complex displacement or even worse, SSS, the only solution I see is a small render farm. I'm running a quad-core hyperthread with 12Gb of RAM and to do high resolution justice and do it in a reasonable time frame I would really need about 3 of those MINIMUM. It boggles the mind sometimes. Reminds me of running Sculpt 3D on an Amiga back in the late 80s..."OH come ON already...Huuurrrryyyy UP!" :)
Not really. Check out Modo. Bloody fast renderer using heavy sets of shaders/micro poly displacement and ray tracing with GI, even on my old P4.
A friend of mine back in L.A. loves Modo. I've never tried it out, but he swears by it.
But nothing rules over TG2 for the most absolutely stunning atmospheric effects. Even to this day I can't help but be amazed.
I was amazed when I trialled Modo. The GI passes are extremely fast. I remember wishing that TG was going to get that sort of speed up someday, no luck on that front yet, though! :D
It's coming I'm sure. The one thing I REALLY like about Planetside is that they don't make over-ambitious claims and then disappoint. They are patient, methodical and quality oriented. If they can't guarantee something by a certain date, they don't even go there...it's done when it gets done right. That's my impression anyway.