Jump to content

How to export vdb's in the right way


Recommended Posts


I have a massive smoke simulation going on, and now I want to export this simulation in vdb's, to import them into a another 3d software (Blender). 

But when I click on the cache button or render to disk button, everything goes well, until frame 70 +-10 frames or so.. and then it stops because I am getting out or RAM. As I have 64 GB RAM, I would love if someone could explain me, how can I export the whole simulation, without decreasing the smoke division size... or smoke quality!

I have tried to just export the density field, but then the smoke looks kinda low res and only if I am exporting ALL pyro fields, like: density, temperature, fuel, vel x, vel z, vel y.... and so on, then the smoke is high-res in Blender. 

But if I am exporting all fields, then it stops after frame 70 because of the RAM... 

is it possible to cut this simulation in parts and exporting them seperatly or somehow optimizing the fields or the pyro sim or vdb's so that I can export the whole simulation without any problems AND in high-res quality?

Thanks for advance


Link to comment
Share on other sites

My guess is that your simulation continuously expands. That means you will always run out of ram. Disable the continuous expansion of the domain and lock down the domain size. This will result in clipping near the edges where density meets the borders. Consider increasing dissipation to remove density before the smoke reaches those edges. I don't think Blender supports motion blur for volumes yet IDK, so you may not need to write vel.x, vel.y, and vel.z to disk. Save some file size and turn them off during final export.


Or kick out .sim files first, and try continuing the simulation a frame before the crash.

Edited by Atom
Link to comment
Share on other sites

Yes, as @Atom noted, disabling the auto-resize would cause your volume to start clipping - review his advice on increasing dissipation to help contain it within locked bounds.

With regards to the number of exports you are wanting, take a closer look at how many you actually need in Blender, Velocity in particular - what field(s) is Blender actually using for the high-res result you want, and are you judging that on what you see in the Blender viewport, or an actual render?  Remove anything you don't actually require for the final result in Blender rather than exporting everything and cut down on the overhead.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...