FLIP Fluids as the next official FX solver in Blender 2.82

Hi,

I know Mantaflow is planned for Blender 2.82 onward, however when I see the advancements of the FLIP fluids addon (https://github.com/rlguy/Blender-FLIP-Fluids), wouldn’t it be a way better addition to Blender than Mantaflow witch is quite student/research typed project and not production oriented.

The young talented dev working on it made the code under MIT license and maybe he would be pleased to help integrate it into the official Blender package and be part of the Blender team.

Are there some known issues about this idea I am now aware of, or simply nobody offered the idea yet ? Because this is obviously amazing and by far the best thing I saw for FX in Blender.

If the issue is money to buy the project, I think many of us would be pleased to contribute so they could join the Blender Foundation.

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Hi,

This is Ryan Guy, a developer of the FLIP Fluids simulator and addon. This project is maintained and further developed by a small team of two (myself and Dennis Fassbaender). I work on the project full-time and my main duties are software development, customer support, and day-to-day business. Dennis works on the project part-time and his main duties are developing multimedia, promotions, and workflow testing.

I wouldn’t say that the FLIP Fluids addon is better than the Mantaflow implementation, or something that should replace Mantaflow. FLIP Fluids and Mantaflow both have strengths and weaknesses. FLIP Fluids has features not available in Mantaflow, and Mantaflow has features that FLIP Fluids does not. For example, Mantaflow simulates both liquid and smoke fluid simulation while FLIP Fluids focuses strictly on liquid simulation effects. It’s best to choose the solution that is suitable for your needs and it is good to have options.

The FLIP Fluids project is supported through sales on the Blender Market. The Blender community has been incredibly supportive of the project and have funded the past 17 months of development since the release. Being able to work on the project full time has allowed for us to improve the addon and add features and user requests that help with workflow and production.

The Blender Institute has recently added Sebastián Barschkis to the Amsterdam team for the next 12 months to work on physics and Mantaflow fluids. Now that the Mantaflow implementation has a dedicated developer, I’m sure we’ll see some great improvements before the official 2.82 release and will continue to improve in future development. In its current state, the Mantaflow integration is still a massive improvement to the current Elbeem solution and something that a lot of Blender users are looking forward to.

The FLIP Fluids project is fully funded through sales on the Blender Market. So far, this business model has been working very well for us and I am happy with the direction that this project has taken under this business model. I am hesitant to switching business models since we already have something that works for us and our users.

I am fully committed to continue development throughout the year for 2020, and plan to continue development in 2021 as long as the project receives adequate funding through sales.

I cannot speak for the Blender Foundation on what possible issues there could be, but the main issue could be with funding the project. I would not be opposed to integrating the addon into the official Blender distribution, but this would require and amount of funding that is competitive with our current level of support as well as competitive with other software development opportunities in my home city (Vancouver, Canada).


If any one has any questions about the FLIP Fluids project, let me know and I am glad to answer!

17 Likes

Thanks Guy for your precise answer.

Maybe then it would be nice if BF hires both of you full time because there is work for more than one person to do a serious multi FX solver.

I understand however that the funding would need to be bigger and as stable money income than what you and your business partner Dennis make together to be viable.

:thinking: I think however that what could be shared and discussed by you and Blender/Mantaflow together, is the concept about a new nodal network logic around the different solvers, that should be agnostic and shared by all upcoming FX solvers (with more solvers in the future, internal/external ones) !

Best

Just adding a small clarification to something I missed in the previous post:

The GitHub project uses both the MIT and GPL licenses. The addon code that uses the Blender Python API is licensed as GPL by requirement. The fluid engine is licensed as MIT and does not rely on the Blender Python API. The fluid engine is structured as a Python module that can be used independently of Blender. The module is imported by the addon and used to run the simulation calculations.

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Viscosity is my only question. I tried few hours to make a liquid be something like that icecream demo of flip fluids has with mantaflow on 2.83 beta… and didn’t even come close. Not even close. Googled and watched some really amateur tutorials of mantaflow…(only ones that seems to be available at all) Is that only achieveble in Flip Fluids?

The FLIP Fluids addon uses an accurate viscosity solving method that takes into account shear stress at the liquid surface. This is what makes it possible to simulate liquids that buckle, fold, and coil. The specific method we implement is this one: Accurate Viscous Free Surfaces for Buckling,
Coiling, and Rotating Liquids

I am not sure of what viscosity method Mantaflow uses, but it could be that it uses a more basic viscosity method that does not handle buckling/folding/coiling liquids.

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@sebbas Sebastian, the FLIP Fluids addon is one of the best addons out there for Blender currently. Mantaflow also uses a FLIP solver, but I don’t think that it has incorporated this paper (‘Accurate Viscous Free Surfaces for Buckling, Coiling, and Rotating Liquids’…see above for link) that was used (per the FLIP Fluids developer) for taking into account shear stress at the liquid surface. Do you have any plans to implement the method given in this paper into Mantaflow so that Blender users (like me) who do not have the means to feel comfortable financially about buying the FLIP fluids addon could still get some of the phenomenal results that the addon can produce?

Each person is the owns of their money and that the best knows their financial status but, let me ask you one thing … You say you don’t have money to buy an addon that costs, literally less than $ 80? But want that another person works to implement those same characteristics that for you involve an expense of $ 80 but for him, they can involve weeks of work on that code, which is equivalent to a few thousand dollars? Seriously?
Cheers…

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Don’t know about the implementation method…
In any case, viscosity settings are working but Real World Size setting is not.

Try to put super high viscosity value (high viscosity value are near zero number I think (check Mantaflow manual about that)
Or reduce your domain size quite a lot.

https://developer.blender.org/T73474

For me Blender Fundation could have made a “Flip-Quest” funding campain to buy the addon :slight_smile:

Hello, Pedro (@povmaniac)! Sebastian is paid by the Blender organization through the Dev Fund to develop Blender and is the person primarily responsible for the development of Mantaflow (although He had been working on Mantaflow long before he was hired by the Blender organization, so thank you, Sebastian for all the unpaid work you put in). Thus, my inquiry to him was not asking him to do something without pay. Further, if you look at the link that was cited, the technique has been implemented in other commercial products besides FLIP Fluids. No one owns the technique, so it is not out of line to ask the Blender developer (Sebastian Barschkis @sebbas ) responsible for Mantaflow if there are plans to implement a technique if those results look even more lifelike with FLIP Fluids than the current implementation of Mantaflow.

Francis (@fr002 ), I am ignorant about much in this area, so I ask that you overlook it if this is an example of my ignorance on display, but I am not sure that viscosity (how quickly a liquid does or does not flow) is the same as the technique’s taking into account shear stress at the liquid surface.