Initial pass taking too long after crash

[Umro]

Hello! I have one strange problem that no one so far knows how to solve.I am working in 3ds MAX.I was rendering a scene of a backyard with a pool.I turned on caustics for the water and activated high quality denoiser. Render resolution was 3520x1980.Everything in a scene is corona proxy.My PC components are NVidia GeForce GTX 1060 8GB,Intel i7-8700k with 16GB of RAM.I know that 16GM RAM is not so good but everything was working perfectly fine until I let it render on that resolution with caustics and denoiser.Everything was rendering normally (but very long,about 20 hours) and I was happy with my noise so I pressed the stop button so the denoiser can start.Then MAX just crashed and after that when I try to render that scene, my initial pass takes hours and it barely even starts doing something.I tried to copy the scene in a new scene,tried to save selected and again tried to render but the same problem was there.I even tried to copy just stuff that is visible only from that camera and it was still like that.Those tries were done with denoiser and caustics OFF. One interesting thing that I noticed was that my processor is working on 3-5% of it's capacity and RAM was on 87% after that crash.Before the crash processor was working on 98-100%.I read about that problem here on forum which said that photometric lights can cause a problem but I have no other lights in my scene except HDRI. I am using Path Tracing + Path Tracing for this exterior scene.I will attach a preview where I was testing the materials so you can see how the scene looks like. That scene was with caustics turned ON. Thank you for your time and thank you on a GREAT engine that I enjoy working in.

[TomG]

Are other scenes rendering normally, or is it just this one that is now slower than it used to be? The minidump from the crash would be good (the one good thing about crashes, and the only one, is that they generate minidumps that say exactly what was happening at the time). May be good to send us a copy of the scene. Info on finding minidumps, sending those and the scene to us via private uploader etc. is at https://coronarenderer.freshdesk.com/support/solutions/articles/5000524006-how-to-report-issues-3ds-max

Other thoughts, what happens if you delete objects to simplify the scene, remove render elements to reduce memory requirements, turn off denoising, or render to a lower resolution? It does sound like running out of memory, so those tests might determine if that's the case or not (any low memory warning popping up or not?)

[Umro]

Thank you for a fast response.All other scenes had that same problem.But interior scenes started working when I moved them to a new scene.This exterior scene still doesn't work.Yes I tried to delete some objects from the scene and removed render elements (I had only basic elements) and turned off caustics and turned off denoiser and the problem was still there even on a lower resolution like 1920x1080 (which was working very fast before that crash). I will try to find something about that crash but the strange thing is that I didn't get that crash screen about sending an error report about a crash.It was just like when you close a folder on your computer.Just shuts down without any messages or anything else. I can't send you a scene because it is a project for a client and not my own.I am not sure that I should have sent that material preview ether but I wanted you to see how the scene looks like because I want to help you try and solve this as much as I can.Sorry

[TomG]

Understood on the scene - of course just to note, any scenes sent to us for debugging are totally private, so nothing would show up publicly as we don't have rights to use the scene for anything other than fixing your problem. Another thought, since you mention the problem remains even if you simplify the scene, if it's possible to delete anything proprietary from the scene and still have the problem show up, then that could be sent in - e.g. replace the house with a cube, remove scattered grass and just leave a plane, replace the chair with a cube, and the problem still shows - that could be sent in as it is still showcasing the problem, but no longer is anything recognizable as a production scene. (And of course if it turns out that it starts working when the grass scatter is removed, then you'll have found a potential cause along the way :) )

[Umro]

Hmm a good idea.I will test it out and let you know if it solved the problem.Thank you :)

[sprayer]

I think it's because of RAM, at denoising it start denoise every layer, if you set in render elements also, and it store it in VFB that's why at denoise it may crash with low free RAM.
20h time is indicate what you have not enough memory and it using HDD space what is much slower. You may try to turn off VFB during render just to check, and turn on autosave rendering on hdd.

[Umro]

Hello! Sorry for waiting so long for me to reply. It wasn't because of the lack of RAM or SSD/HDD space. I made groups of objects by object kind (furniture,trees,bushes...) and hidden them all and left only villa unhidden. After unhiding group by group I came to realise that the trees were making that problem after crash. So I took my model of that villa and furniture and placed them in a whole new scene and I did the scene from scratch (wrote down the coordinates of all the trees and vegetation and placed them again in the scene from my lybrary) and that resolved the problem.I had no problems with that initial pass and render took around 8 hours to complete which was normal for my computer. But thanks anyway for the great response time and advices that helped me resolve this!