Volume object cant be noise free

[thanulee]

Hi, i have a scene with lots of stuff among em, some vdb and a TFD simulation.
Everything on the scene cleans ok except this volume object. TFD and VDB contain voxels as well but they clean relatively easy.

Any tricks i could use for this? I use adaptive noise too and i see no improvement. Im not very picky about noise in general, but this would have flickering if i leave it like this.

At 1080p, i get a render time of 30minute per frame at 4000 samples, with 3 cards which is too much for animation. Cant post this wip, i could send it privately for investigation though. Thanks a lot

[pokeit]

Hey,

light samples seem to have a massive effect on VDB volumes- whack them up super high for any lights that interact with them. Also likewise the amount of specular bounces in the PT kernel changes things drastically.

I'm a noob at the volumetrics in Octane but I am now working on a scene where I'm able to get pretty good godrays in under 2mins per frame on a 1080P image, so there is a way...

Oh and scene scale too. That's also key, stick to real world scales if you can.

Bare in mind that due to, I suppose, what volumetrics are made of (Particles in the air) they will always have a certain 'garunularity' 8/

[thanulee]

Thanks for the response. To clarify, TFD and VDBs clear fine. The octane volume fog that i have (i kept a small scene size specifically for this to work cause it cant handle many voxels), doesnt clear and its not the granularity my issue. Issue is that doesnt clear while everything else on scene is noise free. My next thought was to replace my light emitting objects (street lamps) with actual octane lights but this gives away the lights inside fog etc so im kinda trapped here. In any case, im not expert with vdbs myself, but i ve been playing last month with lots of em and only this volume fog seems to be problematic.

[pokeit]

I have to say I spent a long time on the project that I'm on trying to get a clean 'general environment fog'- Though I also had a god rays set up in it too. I eventually put a VDB in where the god rays where to be and my render times dropped by a factor of more than 10... While I was doing the environment approach I got a huge amount of help from this article (in case you haven't seen it)

https://inlifethrill.com/fog-octane-render-cinema-4d/

[pokeit]

For example it was a bloomin' revelation that the 'thickness' paramater in the top level of the medium should reflect the size in meters of your scene...

[thanulee]

no its not a revelation for me and yes i ve seen it. Ya i know the problem and thats my solution as well, i replace stuff with vdb. Again to clarify: Fog medium clears much better, than this octane volume fog (not even sure about the name has the vdb icon but its not vdb). If u havent use it , its this box container of voxels that u use noises in there. This doesnt clear even on almost empty scenes.

[thanulee]

In any case i d like some otoy guy to reply on this so i can send privately a sample scene to tell me what or if im doing something wrong here, so i know if i can use this object or not. cheers

[pokeit]

Yeah, all highly confusing, have you dropped a line to Beppe? He seems to know the most about all this malarky.

[thanulee]

I hope he responds here 2morrow. thanks again for ur help

[pokeit]

Nay worries soz I couldn't help more (Or indeed at all!), good luck getting to the bottom of it.