Black splotches on final render



  • Heyo, simple issue that I know there's a solution to, but last I read about it was so long ago that I can't find the answer and search results keep bringing up Blender and DAZ.

    Following image shows the issue:

    0_1556821341470_test2.jpg

    The splotches only show up on skin (that I can see).

    Here are my light settings, a point light x 6:

    0_1556822130264_light settings.jpg

    And my render settings:

    0_1556822160279_Render settings.jpg



  • @cujoe_da_man yeah, this is a bug with FF in version 11. It gets worse if you have layered invisible clothing such as cutoff jeans. I can't remember if there is a fix for it. Might try using subdivision of your geometry instead of smoothing.



  • Interesting, I thought I remember that way back in P6-7 too and it was something with the render options. Darn.



  • It also looks like the artifacts you sometimes get when the Shadow Min Bias value is too low (in the light properties panel).


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    My guess is also on the Shadow Min Bias, because the smoothing is disabled in the render settings shown.

    Questions;
    Why is the Raytrace bounces set so high at 6 while 4 is generally overkill?
    Why is the Irradiance caching set to 100?
    Why are the pixel samples at 8 while 6 is already regarded as massive overkill?

    Are there lots of mirrors or lots of glass objects in the scene?



  • @vilters said in Black splotches on final render:

    My guess is also on the Shadow Min Bias, because the smoothing is disabled in the render settings shown.
    Smoothing was turned off because for the props in this scene, I have to disable smoothing for each and every single item or they will "blow up". There are nearly 100 individual objects I would have to do that to in this hallway prop. I also tried it with smoothing on and got the same result.

    Questions;
    Why is the Raytrace bounces set so high at 6 while 4 is generally overkill?
    Raytrace was suggested to be set to that once when I was experimenting with some subsurface scattering mats because they weren't working properly. I set it to 6 and never had a problem since.

    Why is the Irradiance caching set to 100?
    The description literally says "lower values save time" while "higher values are more accurate for better quality".

    Why are the pixel samples at 8 while 6 is already regarded as massive overkill?
    No has ever said anything about this before when I have shown these exact same settings. I don't see an issue here.

    Are there lots of mirrors or lots of glass objects in the scene?
    Slight mirrored surface on the floor (though you can't see it in my sample because teh nudez) and yes, lots of prop objects that make up the individual sections of this hallway scene that the figure is in.

    So then, if we're done badgering me about my render options and not actually offering any genuine helpful information, can we get back on the subject at hand?

    I did another render, this time I turned on smoothing and I bumped the Shadow Min Bias up to 10 and this is what I get:

    0_1556895632266_test3.jpg

    It does appear that the splotches are less now and I could possibly edit them out in post, but this just seems to me like an unnecessary glitch in the program.



  • @cujoe_da_man My honest advise is to not use Poser 11 for FireFly render. It is partly broken. Last version with a fully working FireFly render engine was Poser 2014. Those splotches is only one problem. I did run into other problems when i tried to render older FireFly scenes (mostly from Poser 2014) in Poser 11. Last but not least since SR 4 (i think) my most important specular node for skins ’ks_microfacet’ is broken at least in the Mac version. BTW the problems had been reported years ago but nothing happened.



  • A quick example of other problems that i found. Scene was created in Poser 2014

    FireFly render done with Poser 2014:
    0_1556901158995_TinCan_Poser2014.jpg

    and here FireFly render of the same scene in Poser11:
    0_1556901179790_TinCan_Poser11.jpg



  • Yeah, I've been noticing Smith Micro is good at ignoring problems like this. I might consider Daz, but seeing as how all my content, libraries, figures, scenes, textures, etc are set up in Poser, it would be impossible for me to switch over. I'd lose everything and have to start over from scratch.

    I had a serious glitch with magnets almost two years ago and have been hoping for a fix, but I'm always doubtful it will happen.



  • @nagra_00_ i have compared both pictures a while now and i honestly liked the one done in PP11 more.
    Maybe i have a differend take on this, so it would helpfull to know what issues you have with the PP11 rendition of your scene, whitch i happend to love btw.



  • @cujoe_da_man They didn’t ignore it. After i send in the report together with a test scene to reproduce the issue (the one that looks like a self-shadowing artifact). Tech support confirmed the issue and told me the dev team is already looking into the issue. They just never released a bug fix for it ;-)



  • @marco I don’t like the high gloss/reflection artifacts on some materials on the ground. That the light reflections on the ceiling center are not the same is not so important.



  • @nagra_00_ ok, i can see that. Funny thing is, thats what makes this picture better/more realistic in my oppinion.
    I dont want to dive to deep into this but is the whole floor made with the same amount of specular value?
    It seems to me that the two hatches in the middle of the floor and the two bases on the left side of your picture are somehow more reflective as the rest of the floor.
    I noticed that materials in PP11 have a slidely differend, higher specular value from the start.



  • @cujoe_da_man, one thing i spotted in your settings for the mail light maybe have an influence on your problem.
    The shadow mapp is set to the default value 256. As far as i know this setting means the shadow mapp is 256x256 pixels. This could causes bad/low quality shadows.
    One other thing i don't understand is why you don't activate Ambient Occlusion.
    In the Render Option Tab Indirect Light is tickt on, you have made Min Shading Rate to 0.20, but without AO you have no access to bias and max distance values.



  • @marco I found the scene file and checked the materials. The super bright areas do have both ray reflection and anisotropic. Ray reflection is Ok but the anisotropic node fires like crazy in this scene and light setup. Reducing its value by a factor of 25 or more i get results that look more like in the Poser 2014 render.



  • @marco

    I thought I had AO on, I will check that right now.

    Now that I think about it, does AO need to be on? I thought I read that was what Indirect Lighting was for, it makes its own AO. Was I wrong or maybe read it wrong?

    Also, I have never noticed a difference in anything when setting the shadow maps higher, but that just might mean I haven't done anything that required it to be higher, I shall bump that up and try it out.



  • @cujoe_da_man, if you do this render again, with altered values, it would be interesting to see the outcome.



  • @marco

    I went through and turned on AO on all the lights except for the IBL. I also bumped the map size up to 1024 on each light and this is the result:

    0_1556914119969_test4.jpg

    It does seem like it's less this time compared to the last, but still looks like she's being accosted by some virus.



  • @nagra_00_ , i really think SM Developers have changed the FF Renderengine in PP11 for the better.
    The big change to SF and the integration of cycles materials into the program in mind, i found FF more responsive and faster. The SSS Materials are rendering better then ever.
    And if one has to tweek some materials from older files, its nothing in comparison to the extensive changes one has to make to get some decent results out of the cycles renderer.



  • Firefly's ray accelerator was upgraded for Poser 11, with the result that rendering is a little quicker. An unfortunate side-effect was that the lighting calculations in IDL and IBL renders seem to break down in some circumstances. Gently curving surfaces are one circumstance (in other words, what Poser was designed for) where these artifacts appear when light levels are low. They can sometimes be mitigated by applying subdivision to the surface in question, but not always. The only reliable cure I've found is to render in Poser 10.

    @nagra_00_ and I (and probably others) have submitted reproducible bug reports. I assume that they decided not to fix this bug in a development meeting that took place a long time ago. Sorry to be the bearer of bad news.

    My own (two year old) thread on the subject is here - https://forum.smithmicro.com/topic/877/idl-in-poser-11-a-step-back-from-poser-10