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    A lot of noise when rendering with light portals

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    • M Offline
      martynaaas
      last edited by

      I'm trying to render an interior scene and testing a few settings with Vray rectangle light set as light portal. I got those nice shadows where objects meet ground, however it got way too noisy now. Does this noise come from low subdivs of rectangle light? Or any other settings?


      Render without Light Portals


      Render with Light Portals

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      • V Offline
        valerostudio
        last edited by

        I stopped using light portals. The render times were isane and I did not find that added to the quality of the image, just use regular rectangular lights if you must.

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        • M Offline
          martynaaas
          last edited by

          @valerostudio said:

          I stopped using light portals. The render times were isane and I did not find that added to the quality of the image, just use regular rectangular lights if you must.

          It did increase render time indeed, although I was able to produce those sharp shadows on the ground. I guess it really depends on the quality of renders you're looking for. For this project, we are working on a high-end interior so producing qualitative renders is a must.

          Going back to topic, I was able to reduce noise levels dramatically by checking Sub-pixel mapping option under Colour mapping menu. It's still a little bit noisy but not as much. Changing subdiv count under Vray Rectangle light options did not do too much (went from 8 to 64 and could barely notice a difference in noise levels but shadows got a little bit smoother).

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          • V Offline
            valerostudio
            last edited by

            You cant depend on solely exterior light to render an interior. You need to add lights, the same way you would need to light a space in real life. Sometimes I add a couple of planes just inside the windows to fake in some more light, but you definitely need more lights in your scene or you are going to get splotchy renders.

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            • M Offline
              martynaaas
              last edited by

              @valerostudio said:

              You cant depend on solely exterior light to render an interior. You need to add lights, the same way you would need to light a space in real life. Sometimes I add a couple of planes just inside the windows to fake in some more light, but you definitely need more lights in your scene or you are going to get splotchy renders.

              I have to disagree with you here. I use HDRI + VraySky most of the time which gives me more than enough lighting for any interior scene (considering that an interior has a right amount of openings). I guess your statement is more valid when doing night/evening renders.

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