My render seems to always crash after about a week of rendering so I decided to split it in two parts. This obviosly solved the problem since I've been able to let it run for more than two weeks without any trouble. However, when I brought the two parts into After Effects for compositing, I realized that there's a huge brightness and color difference between the two parts. I assume that this is caused by some sort of auto exposure in Lux.
So, my question is this: is it possible to find out the exact exposure difference between the parts and what's the best (preferably mathematically correct) way to fix it in post? I've played around with exposure, brightness/contrast, curves, tint and hue/saturation in AE but it always seems too dark in some places or too bright in others
Both parts were saved as exr.
Different exposure when rendering different parts of the image
Forum rules
Please upload a testscene that allows developers to reproduce the problem, and attach some images.
Please upload a testscene that allows developers to reproduce the problem, and attach some images.
Re: Different exposure when rendering different parts of the image
Which tonemapper did you use?
If you don't know, you can upload the .cfg or .blend file.
Also, which version of Lux? Did you use the Blender addon, or some different solution?
If you don't know, you can upload the .cfg or .blend file.
Also, which version of Lux? Did you use the Blender addon, or some different solution?
Re: Different exposure when rendering different parts of the image
Are you using Auto-Linear tone mapping ? In this case, it auto scales the image luminance and it explains your result. You should have used Linear tone mapping with the same user defined scale for both renderings.FXtend wrote: ↑Tue Nov 13, 2018 3:29 pm So, my question is this: is it possible to find out the exact exposure difference between the parts and what's the best (preferably mathematically correct) way to fix it in post? I've played around with exposure, brightness/contrast, curves, tint and hue/saturation in AE but it always seems too dark in some places or too bright in others
Both parts were saved as exr.
To merge your already rendered images, it should be possible to scale up/down on of the half images to match the other half. Auto-Linear tone mapping just multiply the RGB values for a constant. It should be possible to multiply again one of the half-images for another constant to match the value used in other half.
Re: Different exposure when rendering different parts of the image
Yep, linear with auto brightness
Thanks for the mathsDade wrote: ↑Tue Nov 13, 2018 3:56 pm To merge your already rendered images, it should be possible to scale up/down on of the half images to match the other half. Auto-Linear tone mapping just multiply the RGB values for a constant. It should be possible to multiply again one of the half-images for another constant to match the value used in other half.
I tried multiplying the brighter half with different shades of grey but I still have the same issue; some parts are too bright while others are too dark and the seam is clearly visible
Re: Different exposure when rendering different parts of the image
Efff, unfortunately, my original post wasn't accounting for gamma correction: it makes the process not linear. So you would have to reverse gamma correct the half image and, only after that step, you can scale the image and than gamma correct again. Sadly, this is a very complicate process because, like said, it is not linear and it is very hard to adjust accounting the gamma correction step.
Re: Different exposure when rendering different parts of the image
The scene looks incredible! The bee, the flower, the lighting - wow!
I'd really like to see it when it's finished.
I'd really like to see it when it's finished.
Re: Different exposure when rendering different parts of the image
Well, you can reverse gamma correct both half so you can match one luminance scale with the other.Dade wrote: ↑Tue Nov 13, 2018 8:42 pm Efff, unfortunately, my original post wasn't accounting for gamma correction: it makes the process not linear. So you would have to reverse gamma correct the half image and, only after that step, you can scale the image and than gamma correct again. Sadly, this is a very complicate process because, like said, it is not linear and it is very hard to adjust accounting the gamma correction step.
Re: Different exposure when rendering different parts of the image
Anyway your image look already unbelievable can't wait the end
Re: Different exposure when rendering different parts of the image
Thanks guys
Really appreciate that after all the trouble I've had with this scene.