Volumes, Upres, VDB Conversion, Dual Rest fields

[WildayHeart]

Hey guys, 

i would like to know if it is possible to keep the Dual Rest fields i created on a low res volume all the way thorugh the upres (using the upres container) process. 

As far as i see it, you can only create one new rest field using the upres DOP. I have a few questions: 

- There is no way to upres your dual rest field? 

- Is there a way to do it without the upres DOP and can you just merge them after? 

- Would it maybe be okay to have the rest fields at a bigger resolution (bigger voxelsize, lets say sim is 0.02 via upres and rest/rest2 is 0.04) and just merge them? I assume this would be a big nono.. 

- Is the one rest field that you get out of the upres good enough? I assume dual is "better" 

- Is there something to keep in mind, when converting to VDB down the line. I had a few issues, where the one rest field i got from the upres, would not really convert to VDB and stayed zero-ed out in the sim. 

 

Hopefully you guys can help me out on this and also shed some light on the topic of upres/rest fields. 

 

All the best! 

Edited December 9, 2018 by WildayHeart

[bunker]

Hey Johnny,

are you trying to upres your sim AND create 2 high-res rest fields for extra details in the shader?
That would be 6 extra heavy volumes (rest.x,y,z rest2.x,y,z) - I wouldn't not recommend that.
The one rest field created in the upres is not for shading purpose, that's for sure.
If you keep a standard upres workflow, you only need to save on field on disk: density

hope that helps.



 

[WildayHeart]

Hi bunker! 

Thank you so much for your response - your posts on pyro and upressing have already helped me a great deal! Really great stuff! 

As for my situation, 

Yes, the rest/rest2 fields i would like to use for details in the shader! How would you go about that? 

Could i use the low res rest and merge with the high res (thus having density, temp at 0.02 via upres, and rest/rest2 is 0.04) 

or any better way to achieve this? I really like the extra detail you get via shader! 

 

[WildayHeart]

The thing i am also wondering is at that using upres or not using upres but the dual rest fields - i guess in the end they both are meant to give more detail to the sim. 

If you only can use either - and cannot combine them - which would be the preferred method? 

[bunker]

you could advect 2 rest fields in the upres but that's a custom setup:
- you'll need to copy the "compute rest" and "advect rest" parts of the smoke solver to the gas upres
- and make sure you include rest and rest2 in your gas resize
that will make your upres sim a lot slower though, since it's advecting 6 extra fields.

Personally, I prefer not using rest fields in general, the details you get out of a good upres are much better than adding noise in the shader.
and you won't get any weird "pulsing noise effect" when the noises are blended between rest and rest2.

examples using upres without noise in the shader:
https://vimeo.com/192893049
https://vimeo.com/192944420
 

[WildayHeart]

Hi bunker! 

Thanks for your thoughts! I will do it like you suggested! 

Actually i had the highres already simmed out and ready to shade, when i remembered how you can add details via the rest/rest2. So i was wondering if they can go together in some way.

I just needed to make sure i am not missing anything  

Really nice! Also thanks for the examples! 

Thanks for clarifying! TBH i like the upres workflow more anyway.. it first it was a little confusing, but with the shelf tool it is actually very easy! 

All the best! 

 

Edited December 9, 2018 by WildayHeart