Next Limit RealFlow 2013
Issue: Volume 36 Issue 7: (Nov/Dec 2013)

Next Limit RealFlow 2013

RealFlow has been the top fluid-simulation application for well over a decade. The software has been used on countless feature films and can simulate everything from water, to fire, to explosions, rigid-body simulations, particle systems, and more. RealFlow 2013 adds to its already substantial feature set with a node-based creation environment and a number of other new features.

The software works as a stand-alone package with plug-ins that support the major 3D applications (Maya, Cinema 4D, 3ds Max, and more). The plug-in allows for seamless transfer of data back and forth between RealFlow and a 3D application. Next Limit, the creator of RealFlow, is also the developer of the Maxwell Renderer, and this can be used within RealFlow to generate realistic previews.

The interface has undergone some major changes. Probably the biggest enhancement in RealFlow 2013 is the new node-based relationship editor. Instead of using menus to create lists of which objects in a scene interact with one another, nodes for these objects can now be connected together visually. Nodes also can be color-coded to keep things organized. This is a big step forward in that it allows much easier authoring and customization of effects. It should improve productivity and creativity by a significant amount.

Another big interface enhancement is the addition of the Simulation Graph. This is a visual programming system that allows you to both create nodes and do programming with scripts or expressions, enabling a much higher degree of customization and control of effects in an easier-to-use interface.

In addition to the interface changes, RealFlow 2013 has a number of improvements to its simulation engines. For those creating explosions and other destructive effects, the Caronte solver improves upon the way geometry breaks apart, known as fracturing. The solver can handle higher-resolution meshes, which gives more control over exactly how an object will break apart.  

For fluids, the Hybrido 2 solver adds the ability to simulate large bodies of fluid. This opens the door to large-scale effects, such as rivers, waterfalls, and surf. The new solver can easily handle millions of particles and not break the bank when it comes to CPU time. Part of this is because Hybrido 2 can off-load tasks to the GPU on the graphics card, significantly speeding up calculation times. I performed a quick non-scientific test of GPU simulation on my Quadro 5000 card, and the simulation speed almost doubled compared to my six-core Intel CPU.

Previews are very important when creating simulations, and they are usually the only way to evaluate results in real time. As mentioned before, the Maxwell Renderer can now be used to generate high-quality previews. This allows artists to save the step of exporting effects to a third-party package for test renders. The results look really good, and the quality of the Maxwell Renderer helps a lot with that. You can use pre-set materials for rendering with the option of importing your own Maxwell materials. A Maxwell license is not needed to render previews.

For connectivity to outside software, RealFlow offers plug-ins to all the major 3D applications. This makes it extremely flexible when it comes to creating custom pipelines. Files can be sent to RealFlow from a content-creation package, such as Maya. The scene can then have effects added in RealFlow and sent back to Maya for additional work and/or final rendering. Additionally, RealFlow now supports the Alembic file format created by Sony and ILM, which is quickly becoming a standard interchange for 3D scenes.  

This release of RealFlow is definitely worth the upgrade. The new interface and node editor make it much easier to use. The additional simulation features add to the already rich feature set. If you do a lot of visual effects and simulation, RealFlow is definitely worth a look. ■ CGW

George Maestri is a contributing editor for CGW and president/CEO of RubberBug animation studio. He also teaches Maya for He can be reached at