Light Leaks

  • Hi everyone. I'm very familiar with the concept of light leaks but I'm experiencing more of them and I'm not sure why. My geometry is closed, solid and flush with adjacent objects. In some cases the leaks appear to be a glitches. Sometimes I add objects to the outside to block the leaks and it works some of the time. Whats causing these leaks when proper process is done correctly?

    Cheers!


    Running version 2.7.2

  • jtubb , can you please, in the first instance, upgrade to our latest release Enscape 2.8? Afterward please get back to me in case you still experience this - then it would be most helpful to receive the scene, and should that not be possible at all, a few screenshots. Thank you in advance!

  • So this may or may not be on topic with light leaks but this is the kind of glitch i'm seeing.

    It's not consistent so i don't know what is causing it and it only appears in this area. The view has a lit of contrast with black and white material so i don't know if that is throwing off the auto exposure. I removed the light and the ceiling appears to be self illuminating. Odd as its not in the adjacent views. Sure an update to the latest version "could" fix this maybe error but i can't risk experimenting. So what do you believe is the causing this area to have a brighter than normal ceiling? If i add more lighting or increase the values i starting getting an undesirable look.



  • Very difficult to say what's going on based on the screenshots. But auto-exposure would explain the phenomenon: While the bright emissive surfaces of your lights are in direct view, auto exposure is reduced and therefore the brightness of other parts of the image reduced. You can try to disable auto-exposure to see if that applies.


    I'm not seeing anything that would classify as a light leak though.

  • I'd agree with others, it looks like auto-exposure may be the culprit. In the view with your lights turned off, the image doesn't actually look any darker - this leads me to believe that the scene isn't being lit by the light objects, but by something else. Maybe ambient light, maybe exterior sunlight. In either case, I'm betting the exposure level is causing the problem, most likely as you noted because you also have a lot of very dark surfaces that are causing the exposure to be bumped up significantly. This is allowing the detail of the dark planes to show up, but is blowing out your white surfaces. This is a pretty common issue, and actually can easily happen with a camera in real life too - it's really a function of our eyes being very good and looking at light and dark portions of our vision at the same time, when in reality the contrast would be too strong.


    One thing I frequently do to get around this is I rarely render with surfaces as true white, unless I'm doing everything white for a more diagrammatic look. Otherwise, all white surfaces are actually a very light grey. As long as that light grey is the lightest surface in the image, you won't see it as grey but just white - but the addition of the grey helps cut out some of the wash-out effect of the exposure.