EC - Hybrido Emitters

RealFlow’s Hybrido solver is a sophisticated and exciting technology, allowing you to simulate large scale scenes, such as extensive water surfaces. For this purpose, a series of data formats had to be introduced, storing the particle data separately. These files are designed for storing huge amounts of data and only contain the most important attributes. The particles from this emitter type are also called core fluid. "Core" describes the body of your fluid, while splashes, foam and other secondary high-resolution effects are created with appropriate standard particle emitters.

Hybrido emitters share most of the data types and file formats of standard fluid emitters: BIN, ABC, ASS, PRT, PD, ASC and PDC, but they are not activated by default. If you have more than one emitter inside a domain and you want to export the particles separately then you can enable the emitters individually here. Please bear in mind that the emitter files are actually only needed for data exchange with your 3D application, for example if you want to render or shade the emitters individually. For the same reason, the stored emitter data files are not loaded into RealFlow. To store and use the Hybrido fluid files in RealFlow, please activate the export resource of the Hybrido fluid domain(s) – this is the only way to load them.

RealFlow support these file/export formats:

Extension	File type
RPC	RealFlow particle cache
BIN	Particle cache
ABC	Alembic particle sequence
PRT	Krakatoa's™ native file format
PD	Particle sequence
ASC	Particle sequence
PDC	Maya particle sequence

Particles cache (.rpc)

RPC is another RealFlow-specific format, but fully documented and supported by the various exchange plugins. It stores the Hybrido fluid's particle data and can replace BIN files. You can choose which data channels you want to export.

Particle cache (.bin)

This is RealFlow’s most common particle file format. It contains all relevant position and physical data, such as density or pressure. BIN files can be read by any plugin available for 3D programs and they are accessible via Python scripting for storing customized particle files. BIN files can be cached by RealFlow to enable simulation data playback via the "Timeline" and they can store huge amounts of data – file sizes of 50 MB, 100 MB or even more are quite normal. This, of course, makes it impossible to play back cached simulations in real-time and you should consider using the “Movie Player” to create previews. BIN files are fully supported by RealFlow’s import and export filters and all available plugins including the RealFlow RenderKit (RFRK).

Alembic sequence (.abc)

The particle of each emitter can be exported separately as a sequence of ABC files. Alembic files for Hybrido domains support multiple channels from which you can choose when you expand the “Particle cache (.abc) branch. In contrast to standard SPH fluids, the particles from Hybrido fluids only carry some channels: position, velocity, texture, vorticity, normal, and id. RealFlow's implementation of the Alembic format supports 10 different compression levels from 0 to 9. A higher value indicates a stronger compression. As usual, the compression requires some time and so the saving process becomes slower, but it is more resource-friendly.

Krakatoa Particle File Format (.prt)

Thinkbox Software’s Krakatoa™ is a volumetric particle rendering system for 3DStudio Max. RealFlow is capable of writing native PRT files for direct use inside Krakatoa™. The PRT format also supports a wide variety of individual channels for all standard particle attributes. You can activate and deactivate them on demand by simply ticking the checkboxes. In contrast to PRT files from standard particles, files from Hybrido emitters only support “position”, “velocity” and “id” channels.

Particle sequence (.pd)

The abbreviation “PD” stands for “Particle Data”. It is a flexible format for particle data. The advantage of PD is that the user can select the data data s/he wants to see exported by simply clicking on the desired attributes. This feature saves disk space effectively. Since PD is also well documented, it is possible for users to write their own importer for reading out the files. As seen in the image, you can choose from a wide variety of attributes. These data can be translated into vertex maps, for example, to visualize particular characteristics of the fluid or render particle based motion blurs. PD files from Hybrido emitters only contain three attributes: “position”, “velocity” and “id”

Particle sequence (.asc)

To write out standard ASCII files (a text format that is valid for all computers), please activate this option. Entries are directly readable and editable with any text editor. Currently, ASC is only supported for writing out files and customized data exchange, e.g. by using your own scripted or programmed readers.

Particle sequence (.pdc)

The PDC format contains similar data as PD, but without the possibility of choosing from attributes. “PDC” stands for Maya’s “Particle Data Cache” and it is an exchange format.