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Black pixel filter

RafmerRafmer Posts: 564
in Technical Help (nuts n bolts)

While checking the log to check my render times I encountered this message:

2016-19-09 19:19:48.851 WARNING: dzneuraymgr.cpp(261): Iray ERROR - module:category(IRAY:RENDER):   1.0   IRAY   rend error: Degraining filter cannot be combined with "black pixel filter".

What is this "black pixel filter"? Which filter is not working if they cannot do it together?

Thanks in advance!

Comments

  • FishtalesFishtales Posts: 6,162

    I think, though I am not sure, but it you have the Crush Blacks set to anything other that 1.0 and the Noise Filter set to On then you will get this message in the log file.

  • RafmerRafmer Posts: 564
    edited September 2016
    Fishtales said:

    I think, though I am not sure, but it you have the Crush Blacks set to anything other that 1.0 and the Noise Filter set to On then you will get this message in the log file.

    That is the first thing I thought; but I set it to 0.0 instead. I will try it at 1.0.

    EDIT: Tried "crush blacks" and "burn highlights" at any value. Also setting "burn highlights per component" ON and OFF but I still get that error message.

    Post edited by Rafmer on
  • ToborTobor Posts: 2,300

    The pixel filters are part of Iray's "degrainer," designed to limit the salt-and-pepper look of underconverged pixels. The warning occurs when you turn on Noise Filter Enable and choose one of the degrainer options 1-5. I've answered this a few times in the past, e.g.

    http://www.daz3d.com/forums/discussion/comment/914082/

    I only have experience with D|S 4.8, so I'm not sure how this might have changed in 4.9. I would assume the warrning happens because D|S allows a user setting that is not actually supported in Iray.

     

  • RafmerRafmer Posts: 564
    Tobor said:

    The pixel filters are part of Iray's "degrainer," designed to limit the salt-and-pepper look of underconverged pixels. The warning occurs when you turn on Noise Filter Enable and choose one of the degrainer options 1-5. I've answered this a few times in the past, e.g.

    http://www.daz3d.com/forums/discussion/comment/914082/

    I only have experience with D|S 4.8, so I'm not sure how this might have changed in 4.9. I would assume the warrning happens because D|S allows a user setting that is not actually supported in Iray.

     

    I used the Iray advanced render settings; it's a preset from Daz Studio itself; I did not change any of the parameters of the noise filter from the default.

    I don't know if I can afford to let the render fully converge to avoid using the degrainer. I achieved only 30% convergence in 16 hours on gpu mode using a 960M graphic card. The next increments of convergence percentage were of the order of 0,03% per update of several minutes. I've done all I know to improve the render speed, but nothing worked. It is the first time this happens to me since Iray came out.

    I'm using DS 4.9.2 by the way.

    This is the image, just in case it helps. I am using two light props from the architectural lights from IG with IES profiles attached to them to lighten the scene.

     

    doh3b.jpg
    1920 x 1080 - 476K
  • FishtalesFishtales Posts: 6,162

    I have the Noise Filter turned off and haven't seen that in the Logs for a while so you are probably correct.

  • ToborTobor Posts: 2,300
    Rafmer said:

    I used the Iray advanced render settings; it's a preset from Daz Studio itself; I did not change any of the parameters of the noise filter from the default.

    Unless 4.9 works differently (I don't know why it would for this), you did something to change the filter setting, or a preset you used changed it. The setting is not active by default. You can always revert to the defaults by clicking the Defaults button on the render tab.

    You don't have to use the degrainer to get a less grainy appearance, as using it could contribute to other artifacts. You don't get this kind of filtration without consequences, so try to avoid it in the first place. Work instead to decrease the overall render times by working with Iray, rather than asking it to cover with bandaid fixes -- better lighting, direct lighting over indirect, less "noisy" materials, and so on. 

    The scene you posted looks severely washed out to me, so I'm not sure what your intent is here. I think you're bound to see more of the effect of unfinished pixels with this type of exposure.

  • RafmerRafmer Posts: 564
    Tobor said:
    Rafmer said:

    I used the Iray advanced render settings; it's a preset from Daz Studio itself; I did not change any of the parameters of the noise filter from the default.

    Unless 4.9 works differently (I don't know why it would for this), you did something to change the filter setting, or a preset you used changed it. The setting is not active by default. You can always revert to the defaults by clicking the Defaults button on the render tab.

    You don't have to use the degrainer to get a less grainy appearance, as using it could contribute to other artifacts. You don't get this kind of filtration without consequences, so try to avoid it in the first place. Work instead to decrease the overall render times by working with Iray, rather than asking it to cover with bandaid fixes -- better lighting, direct lighting over indirect, less "noisy" materials, and so on. 

    The scene you posted looks severely washed out to me, so I'm not sure what your intent is here. I think you're bound to see more of the effect of unfinished pixels with this type of exposure.

    I know that I switched on the noise filter; I meant that I did not change any of the parameters of the default preset. My question now is: if the black pixel filter cannot be switched off and causes conflicts with the noise filter, why would we use it? Or is this intended?
  • mtl1mtl1 Posts: 1,507

    Rafmer, you are probably trying to get a steam effect using volumetrics, correct? I suggest using the Architectural and Caustic samplers because Architectural helps with convergence in indirect lighting scenes, especially indoors and Caustic will help resolve the volumetric effects in your scene.

    Architectural and Caustic does cause the scene to take longer to clear up, but it should converge much faster at larger numbers of samples. It's the only way I can get my complex scenes to converge in a reasonable time frame, and I'm on a 960 4GB. Maybe 4 hours compared to a 18 hour render?

     

    Maybe this way you can avoid the use of the noise filter, if it's giving you grief.

  • RafmerRafmer Posts: 564
    edited September 2016
    mtl1 said:

    Rafmer, you are probably trying to get a steam effect using volumetrics, correct? I suggest using the Architectural and Caustic samplers because Architectural helps with convergence in indirect lighting scenes, especially indoors and Caustic will help resolve the volumetric effects in your scene.

    Architectural and Caustic does cause the scene to take longer to clear up, but it should converge much faster at larger numbers of samples. It's the only way I can get my complex scenes to converge in a reasonable time frame, and I'm on a 960 4GB. Maybe 4 hours compared to a 18 hour render?

     

    Maybe this way you can avoid the use of the noise filter, if it's giving you grief.

     

    Thanks for your suggestions, but it's not volumetrics but a billboard from the environment cam for Iray. However I already had both filters ON thinking in the closed space and the water.

    I tried removing the SSS from the water and played with the refraction color to make it easier, even tried removing the water altogether to check if was causing the problem.

    I played with all tone mapping settings, even following charts of recommended values.

    I hace checked all the materials to fix too white or black not mapped albedos. Fixed too unrealistic glossy values from the conversion to Iray.

    I tried an Iray section node to left apart possible problematic props or geometry. Even tried to render without the figure and water to composite them later.

    None of this worked. Anyway, thanks both for your help.

    EDIT: I changed the lights too and placed two spotlights directed at the figure instead of the lights in the ceiling. And, of course, I removed the fog billboard thinking about adding the effect later in post.

    Post edited by Rafmer on
  • ToborTobor Posts: 2,300
    Rafmer said:
    I know that I switched on the noise filter; I meant that I did not change any of the parameters of the default preset. My question now is: if the black pixel filter cannot be switched off and causes conflicts with the noise filter, why would we use it? Or is this intended?

    I don't think anyone outside Daz knows the answer to that. Certain settings in Iray are exclusive. Activating that filter causes the error to occur, with no apparent means to "unset" another option to compensate. However, since the feature works around an issue that has many other solutions, the idea is to use those solutions instead.

  • RafmerRafmer Posts: 564
    Tobor said:
    Rafmer said:
    I know that I switched on the noise filter; I meant that I did not change any of the parameters of the default preset. My question now is: if the black pixel filter cannot be switched off and causes conflicts with the noise filter, why would we use it? Or is this intended?

    I don't think anyone outside Daz knows the answer to that. Certain settings in Iray are exclusive. Activating that filter causes the error to occur, with no apparent means to "unset" another option to compensate. However, since the feature works around an issue that has many other solutions, the idea is to use those solutions instead.

    You are right, of course. Guess I was expecting an answer from someone inside Daz.

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