RealFlow Particle Importer (PI)

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Last updated: 08 Sept, 2014 by Anonymous
3 min read

Particles are the “essence” of RealFlow's fluid solvers, and there are a quite a lot of different file formats to store the simulation data. You can decide whether you want to use the raw particle data to render the fluid, or if you want to create a mesh. In the first case, the particles are loaded into Cinema 4D, where you can read out properties like velocity or pressure, and use them for the shading process.

To import the particles, the “RealFlow Particle Importer” is used. Simply click on the plugin to add an empty container. This container will not only contain the particle data, but provides tools to visualize the information stored with every particle. This tool is also used to establish a connection between PyroCluster and RealFlow.

Supported File Formats

In order to load the simulation data written by RealFlow it is essential to know which file formats are supported by the connectivity plugins.

The “RealFlow Particle Importer” accepts RealFlow's BIN, PXY and RPC formats for particle simulations. There is also a BIN format for meshes, but it has a different file structure – therefore it cannot be read by the plugin. “BIN” is the standard format for all emitters from the “Liquid – Particles” shelf in RealFlow. This fluid type is also often called “SPH”. The BIN and PXY formats support a wide variety of data channels to store information like velocity, pressure, density, viscosity, the number of neighbours etc.

RPC (“RealFlow Particle Cache”), on the other hand, is used by Hybrido fluids and its secondary elements – the HySPH solver. Secondary elements are splashes, foam, and bubbles. The RPC provides a reduced data set, because for Hybrido simulations it is not necessary to store such a broad range of properties.

PXY is a proxy format. This means that the contained information will compressed to save disk space. The PXY files contain exactly the same channels as their BIN and RPC counterparts.

Although RPC is the default format for Hybrido fluids and secondaries, it is also possible to use the BIN format with these solvers, but not all of the BIN format's available data channels are written. This means that some channels, e.g. temperature or density, will remain empty and cannot be used for shading purposes.

RealWave Particles

RealWave can also store information as a sequence of BIN files, but in that case, the RealWaves node's “Particle layer” has to be enabled:

RealWave node > Node Params > RealWave > Particle layer > Yes

When this feature is active, particles will be placed at the RealWave surface vertices. In conjunction with the “Object Splash” and “Crest Splash” emitters it is possible to create a seamless mesh from the RealWave surface and your splashes, because both elements are represented as particles.

 

 

The vertices‘ velocity information is written to the particles, and they are exported as a standard BIN file sequence. Please bear in mind that this export feature is not active by default, and you have to do this manually in RealFlow:

 Export > Export Central > REALWAVE > RealWave01 > Particle cache (.bin)

The Alembic Format

This file type is a special case, because it can be seen as a universal file format, supported by almost any 3D platform. Alembic is open source and available freely. When you use Alembic files for exchanging data between RealFlow and Cinema 4D you have to consider scene scale. For a more detailed description of the ABC format, please take a look at this page. The Alembic format is not supported by the connectivity plugins, because there is a native import/export filter in Cinema 4D.