Ryan Guy and Dennis Fassbaender took the Blender world by storm with their only Blender Market plugin: FLIP Fluids, a liquid simulator for Blender. Nearly 2,000 copies later, they open up about the process of creating this game-changing addon, and what its success meant to them.

Ryan and Dennis, how did you get started with Blender?

Dennis: I was looking for cheap 3D software to learn how to produce visual effects. After trying Cinema 4D and 3ds Max, I found that Blender had the best workflow for me. For sure, producing things like fire, smoke, particles, fluids, etc. was hard to learn and maybe not the best choice to use Blender for - but in the past years, Blender has become much more powerful! The Fracture Modifier came to us, FLIP Fluids came to us, and Cycles with GPU rendering changed the game.

Ryan: I got started with Blender while the FLIP Fluids simulator was in its infancy - before it was integrated into Blender. This was when writing the simulator was just a hobby for me. I wanted to create animations so that I could show my progress on YouTube and on Reddit's /r/Simulated community, and using Blender is what instantly came to mind. I had no experience with the software, but I had heard that it was free and lightweight. I searched for a script to import and render a mesh sequence in Blender and quickly found something that worked perfectly! I found getting started with Blender so simple - and it allowed me to begin creating renders of my fluid simulations.

Is Blender a full-time job, or do you do anything else?

Ryan: Blender has become my full-time job since releasing the product on the Blender Market. I am developing the add-on on a regular schedule Monday to Friday and work out of Vancouver, Canada - sometimes from my own home, but more often in one of the many public spaces the city has to offer.

Dennis: No, I'm working as an electrician for a big chocolate company in Germany. On the side, I have a freelancing business with video production and VFX. Blender is one of my primarily used softwares.

Do you consider yourselves Blender artists or developers?

Dennis: 50/50 - Actually, I'm in two development teams: Fracture Modifier and FLIP Fluids. I spend a lot of my spare time on these projects, in making tutorials and demonstrations.

Ryan: I definitely see myself as a developer. It's a bit embarrassing to admit, but I consider myself to be quite a beginner with Blender in regards to knowledge of its vast features and mainly stick to the basics of the software. I spend so much time on the simulation and development side of the project that I often do not find a chance to learn the more intricate parts of it.

How did you come up with the idea for FLIP Fluids?

Dennis: I was searching for a way to generate high-quality fluids with whitewater effects (foam, bubbles, spray). While watching some videos on YouTube for my inspiration I found these amazing videos from Ryan - and he rendered his simulations with Blender! I sent Ryan an email and told him of my work from the Fracture Modifier Project and asked if he would like to start a FLIP Fluids add-on for Blender project with me. He said YES! A very happy moment for me.

Ryan: As Dennis said, it started with him sending me an email. Before Dennis contacted me, I was often posting simulations on Reddit's /r/Simulated subreddit. I often read comments requesting that I replace the Blender fluid simulator or create an add-on. It was obvious that there was a demand for an upgrade to the Blender fluid simulation system, but at the time I had no interest in taking up this task. The fluid simulator was just a hobby project for my personal use and the idea of integrating it into Blender seemed daunting. Then Dennis contacted me - he had the knowledge of Blender that I did not have, he had experience developing simulation tools and workflows, and this is what gave me the motivation to start integrating the simulation system into Blender.

What was your process for creating FLIP Fluids?

Dennis: It all started with finding a good workflow. As I had some experience with the Fracture Modifier development it was a good idea to use a similar workflow for the FLIP Fluids add-on. Ryan learned in a very short time how to write add-ons for Blender and started to code his ideas combined with mine. He sent me the first working version. Only basic things worked: simple fluid objects with a domain. I've tested everything, sometimes found issues and often had new ideas. I recorded screencasts about issues I had and possible workflows and finally gave Ryan some feedback. We always agreed on required changes. In this way, after hundreds of hours of simulation/rendering tests, and many test-versions of the add-on, FLIP Fluids became what it is now.

Now, I concentrate on testing new features, searching for bugs, working on the material library, making tests, demonstrations, a tutorial learning series, and producing promotional art for the add-on. We are publishing that all on our Facebook page and Twitter, as well as on the Blender Market page. As an additional project, I've started BlenderPhysics.com where I collect my tutorials from both projects.

Ryan: We started with very small goals and together created a step-by-step roadmap towards the most basic prototype integrated into Blender. Once we had Blender working as the UI to the simulator, our development progress exploded. Before this, simulation settings and geometry were all programmed in a script, which took quite a lot of time to set up. Having Blender available as the simulation interface allowed us to quickly set up and playback simulations, to quickly iterate on and test ideas and features, and to quickly identify and fix issues within the simulation system.

In the final stage before releasing the add-on, we ran a 3 month beta period where over 250 people tested the product and gave us feedback. This was a very important stage of development for us since it let us know the problems that needed to be solved before release. Dennis and I had been working together on the add-on for over a year at this point so a lot of aspects of the add-on made sense to us, but running the beta let us see what parts of the simulator were confusing to a new user.

Right now I concentrate on maintaining and further developing the add-on: fixing bugs, responding to technical support requests, and gathering user feedback to find what features we should add next. I spend a lot of time reading simulation papers and taking a look at other simulation systems to get ideas on how we can improve aspects of our simulator and how to achieve the effects that the users want to create. One of the aspects of development that I enjoy the most is optimizing the simulator. I love thinking of new methods and schemes to get the computer to process calculations as quickly and efficiently as possible.

How has the FLIP Fluids success on the Blender Market impacted what you do? Did you expect it to do as well as it has?

Ryan: I knew there was a demand for an improved fluid simulation system in Blender, but I had never expected this much support from the Blender community. I had never expected that I would be able to support myself financially by developing this project. Our success on the Blender Market has allowed me to continue doing what I am passionate about and to move closer into the city that I love.

Dennis: I was sure it would become a successful project, as many Blender artists (and professionals) were looking for exactly this! But I was also surprised about how well the add-on sells on the Blender Market. It was not the primary goal to make much money with it, but to make a professional tool available for beginners and hobbyists.

The very good connection with Ryan and the success we both have is pure motivation for me. This project became an experience in my life that tells me to never stop working towards my dreams!

What do you do in terms of promotion and building a relationship with your customers?

Dennis & Ryan: We try to answer all questions from customers as quickly as possible and to fix bugs in a reasonable amount of time. We receive emails and messages daily from users asking for help with their scenes, and we try to find good solutions to issues and offer advice. We're always open to starting a discussion and are always willing to take in criticism. We take in feature requests, special requests for tutorials, and we do our best to make these things become a reality for the FLIP Fluids community!

How important is social media in promoting your product?

Ryan: I find that social media is very important and useful for promoting our product. I use the Hootsuite social media management platform. The tool lets me see what everyone is saying about the product across different social media platforms in an efficient layout and makes it easy to keep track of conversations and interactions with our users. If someone mentions FLIP Fluids, I'll see it!

Social media also helps us improve our product. Not all bugs and issues are reported directly to us. Sometimes I'll see a conversation between users about an issue with the add-on and without keeping an eye on social media, we would never know about these problems and would not be able to effectively address the issues.

Dennis: Social media gives us a good connection to the FLIP Fluids users. They share their results with us and other users. In this way, the add-on is promoting itself - which is a fantastic benefit of using social media platforms.

via Gfycat

Where do you see Blender heading in the future?

Dennis & Ryan: I think Blender development, in general, has made fantastic progress in the past and we all are looking forward to testing the new 2.8 version. Being able to make Blender "become bigger" using add-ons makes it even more powerful! I'm sure that Blender will find its way into more professional film studios.

What mistakes do you see other add-on Creators making that may prevent them from succeeding professionally?

Ryan: I think that presentation is very important - and not just the presentation of your product, but also how you present yourself during interactions with other people. This doesn't just apply to add-on creators, but to software development in general.

The first impression of your product is very important, and for us, the first public view of the add-on was during the FLIP Fluids Beta. We wanted to begin the beta with a very polished product with a minimal amount of bugs. We actually did not even make an official announcement for the FLIP Fluids product until just a week before the beta began - after over a year spent integrating the simulator into Blender. The first thing people saw about our product were some awesome animations and when people began testing the add-on, it was at a high level of development and usability which inspired hope that this could be an alternative to the Blender Elbeem simulator. I think that presenting our product well was crucial to our success.

It is also very important to interact with your users in a positive manner. Sometimes I see developers spread negativity which could make users and potential customers rethink whether they want to deal with you. If your users cannot open up a discussion with you, then you may not be able to get the necessary feedback in order to improve your product. Being able to handle criticism well is an important skill for success, as is trying to be helpful and polite in any situation. There is no need to be rude on the internet!

Dennis: I have not really had a deeper look into other developers' success, but my opinion is that it's important to not stop working on a project and ask other people for help to solve some issues! Never say you are better than others. Think about what price you would spend on your tool. Make some renderings and always use only the best of your results for promotions. And never forget to take some breaks - there is a real life out there ;).

Your favorite Blender plugins at the moment?

Ryan: 

• Gaffer - The HDR image manager makes it so easy to set up lighting for my simulations. 
• The Cycles Material Vault - Packed with brilliant materials and is also a great learning resource for material creation. 
• Atom Bomb - I need to clean up unnecessary data before distributing example scenes and this add-on makes this process quick and simple.

Dennis: FLIP Fluids, Fracture Modifier (custom build), Drop to Ground, Pro-Lighting: Studio, Flares Wizard, and ANIMAX.

How do you see Blender 2.8 changing your add-ons, if at all?

Dennis and Ryan: We're still learning about the new capabilities of Blender 2.8, but we are sure there will be some exciting new features that will be made possible with the new version of Blender. Custom drawing in Blender 2.8 has been greatly improved and this will open up the possibility of adding more features that add custom visualizations of simulation data that can help with simulation workflow.

13. Any tips you’d like to share with other Creators for working with the Blender Python API?

Ryan: I find that reading code written by other people can be very helpful. It can give you ideas for how to implement something within an add-on or give insight to alternative coding methods that you would not have thought of on your own. When I started integrating the simulator as an add-on, I was nearly a complete beginner with the Python API. I began by reading the code for the Octane Render add-on to learn about how I could structure the add-on and to see what the Python API could be used for.

14. What is an area of Blender that you see as ripe for improvement, in the same way, that your FLIP Fluids add-on improved fluid simulations?

Dennis: I'd like to see improvements in all physics simulations: A better fire solver, integrated Fracture Modifier (in place of cell fracture), GPU accelerated physics solvers, and a comeback of reactor particles, of course.

Ryan: I would love to see improvements in being able to handle larger amounts of data in order to render massive simulations and visual effects. Specifically in particle rendering. It would be awesome to be able to render tens of millions of particles quickly and efficiently to produce huge effects.

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