Hi folks!
I’ve mentioned this to Svetlin but just to get it onto the forum. Would it be possible to add some functionality into the previewer - file conversion between vdb and aur ( maybe even obj :o ), and downres options? We get most of our fx caches from the houdini department as vdb files and it’s probably worth our while converting them to .aur for render speed. Likewise for things like cloud shots, we use a lot of vdbs and in some cases the files get a bit too heavy. would it be possible to have an option to downres and save out volumes? We’re going to start looking at scattering of vdbs soon so a fast option to batch process a folder of files to make 1/2 and 1/4 res files output to another folder would be amazing!
Thanks so much!
Yyyyyup, vdb to aur is coming, but needs some housekeeping to be done before that. Gotta pay some technical debt left to us by the ancients 
Btw, all of these sound like a job for the cache converter tool. Do you have something interesting in mind for the previewer app and how it would connect to these functions?
You’re totally right - cache convertor would be fine too, probably better with it being command lineable.
Oh, and I see that in the version of next we’re using you have light selects in the normal volumetric mode - thanks for that!
Please consider adding in support for PRT-- like a method to extract the particles from an AUR and convert them to PRT in the command line.
Of course, as joconnel suggested, it would be cool to be able to do it from the previewer as well (perhaps it just invokes the command line tool), but this is just a nice-to-have.
Hey hey,
There will be something in tomorrow’s nightlies - conversion from VDB to AUR using the cache_converter tool I gotta see if I can optimize it, and also please ping me if you have any issues or requests.
Cheers!
Nice!
I’ll give that a go right away!
About 5-6 hours remaining till the nightlies start popping out…
Great, will have a play with this at home - I want to play with some cloudscapes using vdb libraries so I’ll run everything through this first and compare memory / speed!
Hey, also tested converting the Disney cloud VDB to AUR and it allowed us to catch a crash with the Linear Sampler when rendering AUR over 2GB, and also sped up the conversion process in today’s nightlies that are already out - it took whole 7 mins initially, and now takes 3:20 on my machine. Most of the time now is spent in the VDB lib though, gotta see if anything can be done about that. This speedup should also affect Phoenix simulations writing AUR as well. After conversion, the 6 billion cloud is shrinked to a 1.2 GB AUR and loads in the viewport in just 4-5 secs
Ooh, congrats! They’re some decent wins! I did a few automation tools to convert folders before, this looks like it’d be worthwhile for nearly everything we run!
Dragging this back from the dead Svetlin, we’re using this tool to convert a few files to try and get some speed benefits.
I’m having an issue where if I use the cache convertor on a vdb and export a .aur file, it’ll work totally fine in the previewer and list the min / max values for the smoke channel, but when I load it into the vray volume grid in vray next I get no preview and no min / max range in the channels or options to do channel mapping. It seems to work totally fine in vray 5’s volume grid but no joy in vray next. Are there different versions of the .aur specification that are used by each volume grid that we need to match up better?
Oh yes, the AUR format got maybe like 4-5 updates during the last couple years, but I think all of them should already be present in the very very latest V-Ray Next stable nightlies. Which V-Ray Next nightly do you use?
Vray next official release 3.3 in this case!
Hey,
I can only see update 3.2 on https://download.chaosgroup.com/ - it’s from April 2020.
Anyway, you gotta grab a latest stable nightly: Chaos
The changes to the AUR format are from September, so they were not in the official V-Ray - 4.30.00 - check the bullets that mention “AUR” and that new AUR files will not be readable by older Phoenix versions - this also applies to the volume grid in the old V-Ray Next.
Cheers!
Gotcha. So some of the older convertors wont work with our vdbs, will we have any issues with the most recent phoenix being incompatible with an older vray next? I’m not sure if we can swap versions of renderer mid show though I’m sure the supe on it would love to!
Sounds exactly like the issues you are getting. Older V-Ray Next versions do not have the code yet for the newer AUR formats… Can you give the latest V-Ray Next stable nightly a shot just on one machine so that we are sure this is the issue? If it can load the caches, while older V-Rat next can not, then it’s the AUR format, but otherwise there might be a different issue that might need a different solution…
Will check into this later today!
Hey
We have an update in the latest nightlies, the cache converter is now able to increase or decrease the grid resolution of caches:
cache_converter.exe -srcfile “PhoenixFDLiquid001_####.aur” -dstfile “PhoenixFDLiquid001_res_####.aur” -gridresscale=0.2
The new option -gridresscale will decrease the resolution if you use a value below 1.0, and will increase it when using a value above 1.0.
Note that increasing the resolution will simply scale the grid but will not add any extra detail.
Cheers!
