Dark, moody IRay renders that aren't grainy? Suggestions?

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  • Oso3DOso3D Posts: 15,087

    That's encouraging! While I like using canvasses, it's sometimes nice to get the image just how you want it and not add to the render burden.

     

  • ToborTobor Posts: 2,300
    Ptrope said:

    So what you're all basically saying is, "PBR doesn't produce decent images in your lifetime unless you want noon in Phoenix - use 3Delight for everything else." So much for 'realistic' lighting. I may give the ghost lights a try, but I've never been convinced by 'day for night' photography, and I don't really want to spend my time dodging and burning a render that I could get in camera using a non-PBR.

    This post makes no sense. You'd spend considerably more time making a truly realistic scene in 3DL, and it would take either luck, massive skill, or the tools the professional Renderman artists use. And it's not typical for general users to have the tools the animation studios use, as these are not openly shared. Getting a realistic scene in 3DL is significantly harder than in Iray. That's why people prefer using Iray over 3DL.

    Think about how a PBR renderer like Iray works, and you'll understand its limitations, and how to work around them. It works by tracing rays between light source and eye -- boths ways, in fact. Each time a photon hits the eye, its pixel becomes part of the sampling. It doesn't take just one sample per pixel to make it look good, it takes hundreds, even thousands. This is because the ray hits may not all represent the same path. Those paths may produce different results, and there needs to be a certain consistency between these pixels for Iray to judge that pixel as "complete" -- the term the industry uses is convergent.

    Rendering multiple rays to the same pixel takes A) time and B) sufficient rays. Lacking one or the other causes longer renders.

    Maybe you've never been convinved by day or night photography, but real night photography takes time, too. The same physics are involved. Using an emulsion with a reasonable speed for grain, plus lens settings with a decent depth of field, the only other way to produce a usable image is with longer shutter speed. Granted, it may be seconds or minutes and not hours, but obviously the same laws of the universe apply. That's what "photography" means -- writing by light.

  • HaslorHaslor Posts: 408
    edited July 2017

    I really like scenes with lots of shadow and low light sources. I also like explainable light sources, a fire, Glowing staff, or the like. I also wanted to find the really big mistakes. One of the tricks I use is over sized rendering. I offer render at twice or three times the size of the final image, then reduce which helps fill in the grainy bits.

    For instance the following scene is lit only by the staff. (Note: the Staff's Orb, has a Sphere inside, which are both emitting light. While there are two surfaces emitting light, I considered them the same light source.)  Sun-and Sky is turned on, but the time is 22:00 on the 10th of March, so not much light coming from the Sun and Sky. There is no hidden light, both of these are Iray renders and there is no post work, other than the resize. I rendered these at 3840x2160 (Which is an 11MB PNG file)  and then reduced them to 1920x1080.

    The first one is a 1.5MB PNG and was and early attempt. It is a bit Grainy, but not bad.

    This next image is a 557KB JPEG. I moved the staff so it was above her and not in her line of sight. I bumped up the staff emission, which again is the only lights in the. I felt this is a little too bright and I've done some adjustments and I'm rendering a new version, to get you render time, which I will edit in when I get home from work.

    This third shot has several inserts. The orb at the end of the staff, the woman's face, and the cat, with part of the wagon. (Note: this is from before I started work on rebuilding the wagon so it an early version of the Corrected Materials, with !Iray Uber Base applied, no tweaking).

    The staff was an RDNA Freebie from Shoctober 08, I passed the images through Crazy Bump to get it a little more texture, and created a Trans-map so the lightening orb was transparent where there wasn't lightening.

    That is Betheny 7, in a V4 pose from DM (Though I am not sure which pose at the moment). She is wearing Barbarian for V4 from Lady Little Fox, with the !Iray Uber Base applied. I think the Wall is the Hector Ruins from RDNA, Foliage and Old Tree trunk are from Traveler and RDNA, all with the Iray Base applied.

     

    When I get home from work today I will add the latest version and give you render times. This one I've reduced the emission on a little so it falls betweek the two above.

    Hope this helps you

    Who's out there Take 0.png
    1920 x 1080 - 2M
    who's out there Take 1.jpg
    1920 x 1080 - 558K
    who's out there Take 1a.jpg
    1920 x 1080 - 2M
    Post edited by Haslor on
  • SethMSethM Posts: 65
    Haslor said:

    One of the tricks I use is over sized rendering. I offer render at twice or three times the size of the final image, then reduce which helps fill in the grainy bits.

    That is the solution I go to most often. Saves me time messing with settings and reducing image size has been the go-to first tool of choice for image clarity for a long time. Increasing render area doesn't cost as much time as I expect and downsampling in whatever tool I have lying around helps with graininess, aliasing, fireflies, and sometimes even those stupid mistakes I made in posing and positioning. Sometimes. Not often enough.

    I don't go to 3x the height and width. Even 1.5x makes a noticable difference and 2x is pretty easy.

    I get the added benefit that I usually print my renders out on photo paper on a cheapo SOHO inkjet, which is like a whole added level of blurring and smudging and losing information. So that's good. I keep telling myself: That's good. I didn't want all that clarity and color registration, it just got in the way.

  • MardookMardook Posts: 292

    Those look pretty good... I don't see as much grain in them as I would say, my renders. Then again, I don't have the patience to wait overnight for a render... perhaps I should heh. Cheers! :D

     

  • SpottedKittySpottedKitty Posts: 7,232
    j cade said:
    And in case one is wondering how realistic this is here's a nice picture I once took of a sunny day look at those crisp shadows... wait, are those stars? :)

    Not really all that implausible — unless it's a really bright hot-enough-to-fry-an-egg-on-a-bald-head sunny day, many of the brightest stars are still brighter than the surrounding sky. The problem is, you can't easily see them with the Mk.1 eyeball, unless you're looking directly at one, due to the way the light-sensitive parts of the eye work. Cameras don't have that limitation, all you need to do is make sure your exposure is sensitive enough to pick up the stars without being washed out by everything else in the camera view. (On the gripping hand, it isn't easy to hit that exact "sweet spot" unless you know exactly what you're doing and how to get the absolute best out of your camera. Hitting the right exposure entirely by accident is a workable substitute.)

  • pdspds Posts: 593

    Here's a low-light IRay render I did a while back. There are two light sources: the candle flame and a spotlight set to a nice warm color temperature. I flagged the light with a simple plane to control spill on the subject's face, since in the image, her arm would block some of the light coming from the lantern. Tone mapping helped get the look I wanted while keeping the render time reasonable (I have a fast nVidia card, so that makes a big difference).

    bambi_elf2-NGS2.jpg
    1500 x 1000 - 437K
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