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Blend Luxcore not so responsive during rendering

Posted: Mon Apr 27, 2020 7:01 am
by Theo_Gottwald
Ok, while its possible to set HALT conditions, i mostly set them a bit too high. SO that the computer can work on things while I am not there over night.
Now when i get there in the morning i want to save the render.
At this point I experience a lack of response. There would be some more "DoEvents Cycles" nice to have. Maybe optional?
My impression is that at least with larger resolutions the problem gets worse.
So if am there and want to save the picture, i can press the DNOISE button and try to save the picture.
It needs 5 minutes until really something happens.
At very large resolutions of 10Kx10K the problem seems to increase.
At this place a bit more responsibility from the program would be nice to have.
Of course more doEvents may slow down the render a bit.
But maybe there is a way to find a golden middle between speed an responsibility of the GUI.

Re: Blend Luxcore not so responsive during rendering

Posted: Mon Apr 27, 2020 10:16 am
by Dade
Are you sure you are not just running out of physical ram and the OS start to swap on disk (i.e. a very slow operation) ? Try to check with an OS tool how much free ram you have.

Re: Blend Luxcore not so responsive during rendering

Posted: Mon Apr 27, 2020 10:35 am
by B.Y.O.B.
Can you post a simple testscene that shows the issue? Does it happen with a simple cube scene with 10000x10000 resolution as well?

Re: Blend Luxcore not so responsive during rendering

Posted: Fri May 01, 2020 8:04 am
by Theo_Gottwald
Memory Usage in the Windows Taskmanager is below 50%
My impression is that this is resolution dependent.
The higher the resolution of the output, the less responsive the render is.
What i saw during testing is, that the same Scene uses much more memory when rendered in very high resolution.
Now I render it with 7680x4320 and the response is already limited, while the Memory is just at 16 GB from 64.
Another test showed that rendering the same scene with a 10K Resolution did really break the 64 GB Memory that i have.
So the effect of the Swapping may have played a role that day.
Here is a Luxcore Testing Scene.
But i think any complicated Scene will do.
Forum.jpg
PS: It shows my new ugly Covid-21 Virus.
Has anybody a nice electron-microscope-texture for Luxrender?

Re: Blend Luxcore not so responsive during rendering

Posted: Fri May 01, 2020 9:03 am
by CodeHD
This sounds to me like just a long execution time of the OIDN denoiser. Remember it is not a real-time denoiser by design.
You mention 10k x 10k as an example but what are your normal resolutions?
Memory would not be a problem for OIDN as it uses an inernal memory limit, preset in BlendLuxCore to 6GB. You can try increasing it for your system but I wouldn't expect much of a performance gain.

Re: Blend Luxcore not so responsive during rendering

Posted: Sat May 02, 2020 5:59 am
by Dez!
I may be able to help, but I'm likely to say the wrong thing.
To render large images, use "Tiled" on the Perfomance tab. Set the AA value to 1.
To get rid of the need to turn off the rendering, to bring the rendering to the final readiness, you need to render on a separate device (a separate video card, or separate processor cores).

Tiled-rendering works longer, but significantly less load on the computer.
You can keep working on it. Making preview renderers, setting up scenes, shaders - fully working and responsive system.

To make a queue of tasks for rendering I prepare customized blender-files. And I make a list, playlist, in the program B-Renderon which works with Luxcore if in the properties of the task to specify
-E LUXCORE
This program has a "live console" in which you can see all the progress.
Task lists can be saved, rendering can be stopped and restarted.

This is my working process of obtaining 9600x5400 images of 10-20 pieces per project.

I hope I answered the question and helped.

Ah, yes.
The more Tile Size the faster the rendering. But the harder the system is loaded.
I work with 32 or 64 sizes.
I've ever done 16.

Re: Blend Luxcore not so responsive during rendering

Posted: Sat May 02, 2020 11:29 am
by Theo_Gottwald
Thanks for the advice, Dezi.
Let me add that in Tiled rendering i get NO caustics like you see in my demo Scene above.
So tiled rendering seems not really to be an alternative to 128 GB RAM :-).
So what i currently do is, first step i limit the number of samples (of different type e.g. glossy) per pixel, by checking how many samples per pixel that i really need. Then i also play with the Clamping by doing a first small render without Clamping top get the right value.
The i use the two first caches and i check first with a low resolution, which number of samples in the final render is needed.
Slowly i get around. Must say that i use the unsupported Blender 2.90 and have sometimes the effect that for example when i connect wrong nodes that the whole blender just crashes no error message. But its not so much that its a problem.
For more complicated Scenes its better to model just in shading mode and only at the last stage switch to render-preview.
In Luxrender it seems to be more easy to make Photorealistic Scenes, however i do not really know the difference to cycles.
Its just looking more realistic in Luxrender, but still seems to take more time to be really clean. Especially with Glas.

Re: Blend Luxcore not so responsive during rendering

Posted: Sat May 02, 2020 12:40 pm
by Sharlybg
Especially with Glas

What ? Even with shadow color and light tracing. I will say nothing render as fast as glass in luxcore :roll:

Re: Blend Luxcore not so responsive during rendering

Posted: Sat May 02, 2020 9:21 pm
by Dez!
I checked out the Underwater Paintigs from luxcorender.org/example-scenes/ and indeed, when rendering Tiled, caustics do not work.
I think this is very important for jewelers.

Re: Blend Luxcore not so responsive during rendering

Posted: Mon Jun 15, 2020 10:35 am
by Theo_Gottwald
I have now added 128 GB RAM to my system so RAM should not be an issue from now.
From my tests, i can say that rendering in 4K (4096x2160) is responsive and works.

But then if you try above 10K (10200x6800) Resolution then all sorts of problems arrise.
Have several cases now.

1. Get artefacts on the upper right border
2. Render window is nearly unresponsive
3. Sometimes just stays black
4. Sometimes just stops rendering

You can try:
So i recommend that you take the Orange-Juice-Sample-Scene from here (Sample-Scenes) and render it with a resolution of 10200x6800.

Try to resize the renderwindow.
Try to render it for 2-3 hrs.
How does it look?

At this point it does not matter wether i use Tiled or normal Sampling.
To me looks that such Hi Resolutions currently overrun the Luxcore?

@Sharlybg, you are a pro who know which buttons to press. Its a bit like "Bruce Lee for Lux-Render". You are trained and me is Novice.
So i need much longer for the same Opponent :-).

Artefacts on the upper right border see here:
2020-06-15 12_33_58-Window.png
2020-06-15 12_34_25-Window.png

Addendum:
You may ask, why I am interested in this resolution.
Ok, to get the money for my electricity bill back, I upload some of my pictures to dreamstime.
On lucky days people buy these. See here:
2020-06-15 12_44_30-Window.png
So in case someone here also wants to get electricity-costs from rendering back (its just few Bucks per month)
you can also register @Dreamstime to upload your pictures.

I have uploaded Viruses in all colours but only the red one get sold.
So if you upload a virus i tend to say "paint it red".

And yes the best resolution for DT is the 10200x6800 (70 MP).