Applying lens effects takes very long on high res images, freezes whole system

[kosso_olli]

On high res images (around 6k x 4k or higher), applying the lens effects take around 90 seconds after each change. Both GPU and CPU mode. Also, the whole system freezed while doing so. This is no fun at all, which results in not using the lens effects anymore... Can this be sped up massively? I don't even want to wait 10 seconds to be honest. Build 3.50.04, Geforce Titan 6gb

[nikolay.kusht]

We will investigate this further and we will update the thread when we have any news.

[asen.atanasov]

Hi,

Since both CPU and GPU take the same time, most probably your computation fallback to CPU in both cases. This is printed in the output log. 6GB seem insufficient for such a resolution, having in mind that viewports also take part of it. Please, send us you output log.

We will be working on different approach for computing lens effects, but it will take some time. Our current approach is the physically correct way to do it, and it is nearly the best we can do in regard of optimization. The GPU acceleration does pretty good job for large resolutions, so make sure it is used.

Best regards,
Asen

[kosso_olli]

Thank you. If you need any scene file that illustrates the problem, please let me know. In the meantime, I will get you the output log.

[kosso_olli]

Problem is still persistent. Had to render a beauty shot in around 10k width, the generation of Glare and Bloon took around 5 minutes. The render itself was done in about 20minutes, so the lens effects took quarter of that time. Too much if you ask me.

[asen.atanasov]

Hi,
can you send us the output log?

Best,
Asen

[kosso_olli]

Sure,
here is the log with hardware acceleration enabled.

[kosso_olli]

Okay, I have another problem with the lens effects now, it looks like a memory leak. I have a rendering of 17412x13062px, the scene takes around 90gb to render including all render elements, motion blur etc.
When the lens effects calculation begins, the system runs out of memory (128gb in my machine) and freezes the whole system. The calculation for lens effects never finishes.
Is it expected that the lens effects take around 30gb of additional memory, even with these high resolutions?

[kosso_olli]

Problem is still persistant in 3.60.03
Glare took 2:23mins and bloom 2:11mins on a render 8500x6375px.

[vlado]

We have not done any changes there. Fixing this issue requires a complete rewrite of the implementation, which will take some time.

Best regards,
Vlado

[kosso_olli]

I know there are no changes described in the change log, but I just wanted to make the developers aware that this is still an issue.

[vlado]

I know there are no changes described in the change log, but I just wanted to make the developers aware that this is still an issue.

Yes, we are very much aware

Best regards,
Vlado

[kosso_olli]

Problem still persists. The calculation for bloom took 3:30 minutes, glare took 5:28 minutes
Whole system froze.

[DanSHP]

We've had the same problems. We render out 5k usually.

We just avoid using the effects at all now. It just isn't responsive enough on larger renders. Shame.

[fraggle]

Same here, Vraynext, with 3000x4000px, not so big, but lot of light.
It's impossible to adjust the effect in the VFB.
By the way, I do have 48GB on this Workstation, so it is not a RAM issues, and I doi have 3 GTX serie 7 on it, that didn't help;