How to reduce Alembic Mesh file size in Bifrost Fluid Simulations ?

[Anonymous]

 I have created many fluid simulations using the Bifrost tool in 3Ds Max. I am trying to make a mobile game that uses water animation exported from Bifrost. When I export the mesh in Alembic, the file size is always very large. It can go up to 1 GB for simple water animations.

I have tried reducing "Master Voxel Size", reducing "Surface Particle Density" but then the liquid starts disappearing from the scene. I am aiming to build a 2-3 Mb water animation (in .abc format) of water flowing from one cup into another. Is it possible in bifrost ? Any help will be really appreciated.

[hagen.deloss]

Hi @Anonymous

Thanks for bringing your question to the forums, it looks like you are visiting as a new member to the 3DS Max forum. I want to extend a warm welcome to the Autodesk Community!

That's a great question, and I'm super excited for us to work on finding a solution. Have you seen this article on optimizing Bifrost simulations?

Also, a quick note on Master Voxel Size, it says in this article that "lower values produce greater detail and accuracy, at the cost of more memory and longer computations."

I would say testing different Bifrost settings while referencing this article would hep get you some answers. If you are still unsure,  would be more then happy to do some tests on my end to see how small a file size we can export these fluid simulations down to 😄

Looking forward to chatting with you further!

Please select the Accept as Solution button if a post solves your issue or answers your question.

[hagen.deloss]

@Anonymous

I wanted to check back and see if a post helped you with your problem. It would be super helpful if you could add a post with how you decide to proceed, and your results. That way other Community members can benefit from your process 😄

Please select the Accept as Solution button if a post solves your issue or answers your question.

[Anonymous]

Hi @hagen.deloss

Thankyou so much for you reply. I was actually using the same forum to adjust my Master Voxel Size, Time Stepping and some other optimizations to generate a small-sized Mesh while also ensuring that the liquid quality remains somewhat acceptable/real.

I made multiple clones of my solver and tweaked different attributes until I got close to the desired liquid. The best result I was able to achieve so far was a "12.5 Mb" mesh size with a Master Voxel Size of 15 (I know the voxel size is very large but I am aiming to get a 2-3 Mb Mesh cache). The "Time Steps" attribute was 30,000 but computation time is not a problem because my focus is obtaining a Cache Mesh in .abc format. However, the problem is that with this Voxel Size, now the liquid is very unrealistic. Please see the video of my result when I exported the cache into my game engine and played it over there.

I have also attached the .max file in which I created the Bifrost Simulation. I have 6 solvers in Bifrost. The one I am talking about above is the solver named "StepsIncreasedOnly".

[Anonymous]

The forum is not letting me upload the .max file. I was able to upload the video in my previous message.

[hagen.deloss]

@Anonymous

Whoa the two glasses look great! I totally see what you mean on the voxel size making the water look unrealistic, the water material looks wonderful! I have some ideas on how to resolve this, but I wanted to take a quick minute first to help you attach the scene files.

If you add the scene file to a zip file, it should attach. If it's still giving you issues, you can send me a private message with a filesharing link instead. 

I will take a deeper look into a solution to this and get back to you 😄

[hagen.deloss · Accepted solution]

@Anonymous

I did an .ABC export on a fluid simulation with a voxel size of .8, and it saved out as 343mb (it was a lot of splashing). I then re-simulated it with a voxel size of 1, and adjusted the smoothing number under the Display Settings tab, and it saved out as 99mb.

I'm wondering if you could lower your master voxel size again (for a less blob-like water), but then also adjust the smoothing and droplet settings in Display Settings?

If you are still not getting acceptable results, you may want to consider an in-engine solution, I found this neat asset video, not sure how big a deal fluid simulation is for your Unity project, but if you use it a bunch, it may be something that could help!

I look forward to seeing you get the best water ever!! From that single video I say, I'm already excited about your project!!

Talk to you soon,

Please select the Accept as Solution button if a post solves your issue or answers your question.

[hagen.deloss]

@Anonymous

I wanted to check back and see if a post helped you with your problem. It would be super helpful if you could add a post with how you decide to proceed, and your results. That way other Community members can benefit from your process 😄

Please select the Accept as Solution button if a post solves your issue or answers your question.

[Anonymous]

Hi @hagen.deloss

So sorry for the late reply. I was extremely busy with the same project. Regarding your advice in the previous message, I did try to decrease the Master Voxel Size for a less blob-like structure. It does help with avoiding blob-like structure but the size increases dramatically. Adjusting everything, I could achieve a size of 12.5 Mb Cache Size for the above water animation but I wanted a 2 Mb max cache size because I am making a mobile game.

I have used the mentioned Unity asset "Obi Fluid". It has very realistic fluids and it is good overall in terms of quality. The problem with these kind of simulations is that every physics calculation is rendered in real time. Therefore, it takes a huge amount of computation time. The only phones capable of running the same animation in "Obi Fluid" that I made in Bifrost, were running on the latest versions of Andriod (8.0 and above), even that with considerable lag. Another problem with this asset is that it not as extensive as Bifrost. With this asset, I can only adjust the Time Steps to a maximum of something around 3. Even if we do not consider the fact that all physics calculations that come with increased "Time Steps" will be done in real time, even this is not a big number. In Bifrost, I used a Time Steps value of "30,000" to achieve a result where no liquid leaks out of the object.

If you have any other solutions, I would love to try more options. Currently, I am thinking of the Unity Particle System, to create something like a fluid of my own.

Please give me your review of my idea or any else ideas you have. I would try my best to respond swiftly.

Thankyou so much
Regards

[Anonymous]

This is my .max file for Bifrost water simulation

[hagen.deloss]

Hi @Anonymous

I would still suggest lowering the display settings for your fluid to see if that helps, when you preview the simulation as a cache mesh, changing the smoothing to 1 and the droplet and surface radius to 1 as well may help make the mesh  output to a smaller size. 

Otherwise, I feel like a built in system should be a lower impact bet for an in Engine solution. Sounds like some juggling is in order between quality, length, and file size! 

Please select the Accept as Solution button if a post solves your issue or answers your question.

[hagen.deloss]

@Anonymous

Here is another Unity option that's free!

Fluvio Fluid particles in Unity