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I feel it's worth pointing out that this is an issue with render quality, rather than render speed, and most of the advice being offered thus far seems to be aimed at making the OP's renders faster, without solving the underlying quality problem he's asking about.
With poorly-optimized render settings I can produce grainy renders on a $20,000 pro workstation (I'm talented that way), I just get to the disappointing result faster 🙂 More speed, RAM, cores, higher-end GPUs, etc. won't fix the quality problem, in other words, even if they do make working with DS and other 3D software much more pleasant.
The problem in this case--the issue causing the "grain"--is a lack of light in the scene. This is comparable to the "high-ISO noise" you get when you try to take a photo in a dimly-lit room without a flash. You can denoise it (in DS or in postwork), but it's always better to solve the lighting issue if you can.
Often in situations like this you can see a difference when you add an HDRI lighting setup to the scene, so that's one way out of the problem--use someone else's pre-calibrated lighting setup. That's kind of a "black box" solution, though, in that it doesn't teach you anything about lighting.
In general--whether you're using a laptop or a $20k pro workstation--you want to configure your Render Settings to some sane defaults, and use those settings until you gain a better understanding of what they do and when to tweak them. As a starting point, try these Render Settings:
Filtering
Fireflies
Firefly Filter Enable: On
Nominal Luminance: 100
Bloom Filter Enable: Off
Post Denoiser Available: Off
Pixel Filter: mitchell
Pixel Filter Radius: 0.70Optimization
Max Path Length: 10
Caustic Sampler: Off (unless the scene contains liquids)
Guided Sampling: Off
Instancing Optimization: MemoryProgressive Rendering
Min Update Samples: 5
Update Interval (secs): 5
Min Samples: 20
Max Samples: 15000
Max Time: 259200 (i.e. max setting)
Rendering Quality Enable: On
Rendering Quality: 1.0
Rendering Converged Ratio: 95%Try a render of your scene with these settings, and the grain issue should go away. Experiment from there with the intensities and positions of the individual lights in your scene to get the result you're after.
Basically what Queensknight said, but shorter. The rest of the stuff doesn't really need to be touched unless this doesn't work.
The render will take longer.
You can go to your render settings. Then in the left tab called Progressive Rendering.
Change:
Max Samples to like 10,000 from the default 5,000.
Render Quality to 3
and Render Convergence Ratio to 99. (Don't put it at 100)This will take the grain out as it allowing the render to continue longer than the default.
You can allow it to render longer by changing these numbers higher. But you really shouldn't need to. I recommend learning Ghost lights. It will speed a lot up for you.
"Ghost light One" is really all you need. The first 3 don't work in Daz 4.2XAgreed re: ghost lights, whether from a pre-packaged kit or made by hand (any surface in your scene can be made emissive with a few mouse clicks and the built-in Emissive Shader).
The main benefit of ghost lights is also the main drawback--no reflections of that light are considered by the renderer. That speeds things up enormously, but at the cost of some realism that you might care about--the glint of light you'd expect to see in a character's eye, say, or along the edge of a curved, shiny surface. That's the tradeoff with ghost lights, and often it's worth making, but it's important to know what you're giving up.
I like ghost lights for preview renders while I'm developing a scene, for example, because I get to see the result quickly, but when it comes to final output I almost always use real lights for a realistic finish.
There's room to mix ghost lights and real lights in a scene, too, in the event there are certain lights you really need to model accurately. Say you have a couple having a candle-lit dinner in an otherwise dark room. The candle(s) on the table need to be real (IMHO) because they're illuminating the people's faces, and those eye-glints matter, along with reflections on shiny silverware, etc. But the room might still benefit from some (dimmer) ghost lighting in places to give the scene some context. Reflections for that kind of ambient lighting matter far less, so it makes sense to use ghost lights to get the illumination boost without adding to the rendering workload.
Also a good trick would be to a) reduce glossiness on some nonessential surfaces, like clothing, walls and furniture (you'll be surprised to find out that very often they come with the max settings...), then b) crank the lights to double of the intensity you already used and c) set a darker color shade to those lights.
This will flood the interior scene with a lot of "grey light" - which will not reduce the rendering time but will give you a less grainy rendered image in the same amount of time it took to render a scene with dimmed white light.Thanks to all for comments received. I think I've only been seeing the "this rendered in 15 minutes" comments, so with my more limited setup I always figured that a longer render time should be expected.
I'm currently trying out all these suggestions to try and tweak my renders and I'm already seeing improvements!!!
So I'll say it again, to all, thank you 🙂
@Unusualsuspex The iterations part that queen and I were talking about will make a big difference for you. The default render settings just are not simple enough. Even with a 3090 ti and your settings, it would be grainy.
The iterations is how many times it basically looks at the scene and see's what needs to be done.
Larger scenes 5,000 iterations is not enough. Just 1 G8 standing there in a photo booth maybe sure! But a scene in a bar with to characters. 5,000 iterations is not enough.The 95 thing too. It's looking to see if the scene has been 95% rendered (Not really but its the best way I can explain it) so 99% is better. 100% it will honestly never reach so just don't do 100%. I've done 99.5 before even 99.8 but I couldn't see any difference in the scenes I was doing with like 12 people in them.
What we're all saying, here, in our own different ways, is that there's no such thing as a "perfect" render. "Perfect" realism would require an infinite number of iterations, and we're looking for results on a much shorter timeline, so we have to define for ourselves what we consider to be "good enough" for our purposes. As we've already seen in this thread, that can vary pretty widely from one person to another 🙂
Think of "iterations" as the number of times we let a photon bounce off of a surface in the scene before we decide that it won't have any more noticeable effect. In the simplest case--one iteration--we let a photon strike the surface of one object and then we stop and move on to the next pixel. That one-pass render would give us a rough idea what the scene looks like, but it will look pretty "flat" because it hasn't considered where else the light would have bounced from there, what reflections and refractions would have taken place, and what areas would have been left in shadow.
If we let the photon go one more bounce, we might find that it hits a second object, but since it has traveled further its luminance has faded (by a factor of the square of the distance), so its illuminating effect on the second surface is exponentially less than it was on the first. Let it go a third bounce and it might strike a third object with even less luminance, and so on, until it either bounces out of the scene or grows so dim that its effect on any subsequent surfaces would be negligible.
Every photon impact contributes a bit of its luminance and colour to a surface, though, whether it's a primary impact or a (weaker) subsequent bounce, so we can't ignore those tiny contributions from those reflections--they add up. The vast majority of a pixel's light and colour is determined by primary impacts, obviously (i.e. direct light), but it's the sum of all the secondary impacts (indirect light) that gives it its "real" and "3D" qualities.
How many bounces do you need in order to end up with a scene that looks "real"? That's the judgment call we're making when we talk about iterations. Personally, I've noticed that it takes at least 500 iterations to capture glints in eyes, for example, and I'm seldom happy with renders that stop before 2000 iterations. For a "final" render I might want 5000 (or more), depending on the complexity of the scene.
The other point being made, here, is that iterations is just a number, and most of us just use it as a rule-of-thumb for the types of scenes we tend to render. How many light bounces you need in order to make YOUR scenes look photo-real is going to depend a lot on how many surfaces there are in your scene for light to collide with. If you have no walls, for instance (e.g. outdoor scenes), photons will likely leave your scene after just a few bounces. But with walls to keep those photons bouncing around in the scene, and reflective and refractive surfaces for them to play with, they'll have a grand ol' time in there, ricocheting off of everything 🙂
As a rule-of-thumb, then, brighter scenes will reach your photorealism threshold in fewer iterations than darker scenes. The more surfaces you have in your scene, the more iterations it will take for you to reach that same threshold. Better hardware will get you to that result in less time, but whatever hardware you've got will do the job if time is not as important as quality.
Another shortcut that hasn't been mentioned here yet is to use a tool like the Iray Stand Kit to limit the rendering area to the part of the scene that you care about. Consider a situation where you have a scene set in a massive, ornate cathedral filled with rows of pews, flying buttresses, banners, and lots of detailed surfaces. There's a dais at one end with an altar on it, and chances are the scene you want to render is taking place just at that end of the room. You might think that since you only have the altar area in your rendering camera shot that's the only space that lighting is being calculated on, but you'd be wrong--light is being bounced around the whole cathedral behind the camera, too, because some of that light may bounce back into the altar area. That render would take ages, and for a very minor realism enhancement.
You could choose to hide or delete the surfaces outside your rendering area to solve this problem, but the Iray Stand Kit does that for you. You just sink the "stand" below the floor of your rendering area, size it so it's just a bit wider and taller than your render frame, and now the only area being considered for light bounces is the space you're looking at. That's a big time-saver in nightmare scenes like this.
@Jinx your link to this AI denoiser is impressive. I have tried out this link with a old render from me and the result is incredible. Thanks a lot for this advice. My system is just mid range and the results are well but with this AT denoising thing it´s so much better. I never have thought about this possibility to use a tool like this. I should buy me a AT denoiser to pimp up my render in that way. Thank you for this tip. 🙂
@Legolas18 thanx for the link to Topas DeNoise AI, i`ll give this software a try. 🙂
I was surprised to read on the Daz forums that many people stop their renders around 70% convergence. I suppose if it looks good (the real test) then that's OK but I usually have to leave it till at least 95% before it becomes clear enough.
Judging by some of the very noisy promo images, I reckon some PAs couldn't be bothered to wait long either. You'd think if they're trying to sell their stuff they'd try to make it look the best they can.
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