Why do so many Superfly renders look like they were printed on sandpaper?



  • I'm seeing this a lot lately. Renders in which the artist obviously put a lot of effort into populating the scene, posing the figures, etc. but the renders look, well, like they were printed on sandpaper. I think its called color noise. I've never used Superfly except by accident, but my Superfly renders have that same grainy look, which is why I'm blaming Superfly for this. Here is an example of what I'm talking about. 0_1538531394758_SuperflySandpaper.png



  • Likely the render settings are too low. Superfly renders can take a long time to render. Sometimes people use the lower settings to render faster. Also different settings work better for different scenes. It can be difficult to get them just right.



  • @redphantom exactly! Impatience, and better things to do than fret over a PC mired in molasses due to multi-hour/day renders with sufficient samples to eliminate all the fireflies.



  • Why not render in Firefly then?



  • @elzagna Because Superfly is better? When used correctly? :)

    Superfly can do some things that Firefly can't. Proper PBR for one.

    Since I figured out (at least somewhat) how to use Superfly, I've only rendered in Firefly by mistake :)

    It doesn't necessarily take days, it depends on several factors. Of course, the computer used is a major part of it. But I was used to Firefly renders taking a day or so on my old computer, so anything less than that is "fast", now that I finally got an up to date machine.

    One thing that slows down things, and, at least to my eye, doesn
    t make any improvement (quite the contrary) is the Branched Path Tracing. I simply can't figure out how to use this. So I don't :) But whenever I give it a try, it produces "sandpaper" :)



  • Maybe it's because folks like you don't take the time to learn how to use new tools effectively.

    Your generalization about Poser users/Superfly renders is unwarranted and brushing with a very broad brush without taking the time to see and learn.

    You berate excellent Superfly renders by those like Ghostship and Jura and many others who have taken the time and expended the talent to learn how to use the tools they purchased.

    You should try it some time.



  • Oh, good lord! Really? You take something as innocuous as this and make it personal?


  • Poser Ambassadors

    @elzagna said in Why do so many Superfly renders look like they were printed on sandpaper?:

    I'm seeing this a lot lately. Renders in which the artist obviously put a lot of effort into populating the scene, posing the figures, etc. but the renders look, well, like they were printed on sandpaper. I think its called color noise. I've never used Superfly except by accident, but my Superfly renders have that same grainy look, which is why I'm blaming Superfly for this.

    Superfly is a bit different than Firefly in many ways.
    Using CPU versus GPU also adds some things to watch out for.

    Firefly is not a bad render engine, and people have used it for more than a few years.
    People get used to things that way, and firefly can produce very good renders if set up right.

    Superfly is a good engine as well, but simply throwing Firefly settings at it isn't going to work out real well.

    Where Superfly has some advantages, and disadvantages at the same time, is lighting.
    True GI, etc. But at the same time if it is light starved, it will take a long time to clean up, if it even does clean up.

    You can't expect a render engine to render something that isn't lighted well, and Superfly shows that far more so than Firefly depending on the lighting used.

    Another issue in Superfly, is how you light it. Many people use an environment sphere, and they don't work right more often than not. Using the background shader is a better way to go. It has all the ray cast info in it the render engine needs, where a sphere does not.

    The number of samples in Superfly has a lot to do with render quality, and I am not just talking about the settings in the render engine. Sometime you need terminators in the shader, to go transparent versus defaulting to black because there isn't any light to see.



  • @trekkiegrrrl said in Why do so many Superfly renders look like they were printed on sandpaper?:

    @elzagna Because Superfly is better? When used correctly? :)

    Superfly can do some things that Firefly can't. Proper PBR for one.

    Since I figured out (at least somewhat) how to use Superfly, I've only rendered in Firefly by mistake :)

    It doesn't necessarily take days, it depends on several factors. Of course, the computer used is a major part of it. But I was used to Firefly renders taking a day or so on my old computer, so anything less than that is "fast", now that I finally got an up to date machine.

    One thing that slows down things, and, at least to my eye, doesn
    t make any improvement (quite the contrary) is the Branched Path Tracing. I simply can't figure out how to use this. So I don't :) But whenever I give it a try, it produces "sandpaper" :)

    The branched path tracing integrator (formerly called non-progressive integrator) is similar, but at the first hit it will split the path for different surface components and will take all lights into account for shading instead of just one. This makes each sample slower, but will reduce noise, especially in scenes dominated by direct or one-bounce lighting. To get the same number of diffuse samples as in the path tracing integrator, note that e.g. 250 path tracing samples = 10 AA samples x 25 diffuse samples. The Sampling panel shows this total number of samples.

    To visualize how this works, the Progressive integrator simulates one path (or ray) per sample:

    The Branched path integrator splits the ray, sampling multiple directions as well as multiple components of the material (e.g. glossy, diffuse, etc) in one sample:

    This is helpful because it takes into account light from multiple directions as opposed to only one, as well as giving more control over how different shaders are sampled. (this also helps reduce fireflies, see What is the Reason Cycles Creates Incorrectly Colored/Firefly Artifact Pixels?)



  • Superfly was meant to be used primarily with a CPU, but Cycles likes and prefers GPU. So while you can and are able to get a decent render with the CPU, it will take some time. I don't have GPU, and no I don't want to sit around to render ever day and a half, so I usually just settle for a less quality render with noise. "sandpaper".


  • Poser Ambassadors

    Here is an example on how you terminate a shader to transparent at a defined number of bounces.

    alt text

    Obviously this is a blender screen shot, but it works the same way in Superfly.
    You can use a setup like this to stop the render engine from trying to see light thru transmapped hair.
    If you don't do this, and the render engine doesnt have enough trans bounces setup by default you will get black in the hair, versus transparent.

    There are a lot of tricks that need to be included in Superfly setups that you don't need in Firefly.

    So in some respects, learning how to use the engine is key to getting good renders.
    And that is no different with any other engine either.
    You either have to know how to use it, or it isn't going to look so good.



  • For the record, Iray will produce grainy renders as well, if the settings are not right. There's a whole thread over in the DAZ Commons on the topic.



  • The number of Pixel Samples set combined with the available light have an immediate influence on the grainyness of your render. On average
    20 samples at normal light will result in grainy shadows and otherwise dark spots. My machine takes about 15 to 30 minutes for such renders.
    At 30 samples most grainyness will be gone, 50 is the practical maximum. Renders times will be higher too of course.
    Poser also offers some presets (bottom left), maybe try these if fiddling with the settings doesn't work out.

    0_1538690536001_render settings.jpg

    Also, the grainyness in my renders is usually intentional, it creates a certain mood, and recreates the grainy pictures of film photography.
    Taken in 2013. Actually a bad picture showing more grain than intended ...
    0_1538690845496_10808505894_a8b3d08d3b_z.jpg