Now it is finally time to start RealFlow. Experienced users will surely get along easily. New customers should first read through this section to learn how to get started with the program and some of its numerous possibilities.
After RealFlow has launched, a window appears. This is RealFlow’s "Project Manager" and contains functions to create a new scene or open an existing file. By default, all new files are created in a certain directory. This specific path can be changed permanently under "Preferences", but for the very first project it is currently not necessary to alter this path. The “Preferences” also provide options to adapt RealFlow to your favourite 3D platform in terms of axis setup and scale.
RealFlow’s "Project Manager" window during startup.
First of all you must enter a “Project name”. By clicking on the “CREATE A NEW PROJECT” button, RealFlow generates a set of different folders, where the simulation files will be stored later. All these folders are grouped under the project’s main directory, carrying the name you have entered before. If you did not specify an alternative path, everything is stored under the program’s default location, which is printed one line below. “Full path” displays the entire path to your scene including the previously entered project name.
A scene can be opened with the appropriate button on the upper right or via the “Recent projects” list. To open a file from this list, simply double-click on the desired project. As long as the "Project Management" window is visible, it is not possible to access the underlying windows or panels. You first have to either close the window or define/open a project. Now enter a name of your choice, e.g. “Object Filling”, and click on “CREATE A NEW PROJECT”, or directly define a new path to a custom directory and then create the project.
You can start to add emitters, objects and forces immediately and start your first simulation. We want to go through these very first steps with you. In this basic scene a vase-shaped object should be filled with fluid particles. The first object will be the vase: in the upper part of the program's interface you can see a bar with different icons. A click on these symbols either triggers an action or creates a simulation element, also called “node”. To add the desired node, please look for this icon and click on it:
After you have chosen the “Vase” object you will recognize that it has been added to the viewport, but also to the “Nodes” window and the “Relationship Editor”. Position and scale of the newly created objects are fine and we do not have to change anything. The second node is a particle emitter and this will be the fluid source. A list with RealFlow's emitters can be found here:
The emitter's viewport symbol shows an arrow pointing downwards – this arrow indicates the direction of emission. To make everything a little more interesting, the emitter will be moved upwards and rotated. Change the view to “Front” with the 2 key. The emitter can easily be repositioned with the “Move” tool that is activated with the W key. Now you can see three axis for each spatial direction. Click on the axis, pointing upwards, and move the node roughly 1 grid unit. A rotation is performed with the R key. Once this tool is active, the emitter shows three circles. Again, each circle represents one direction in 3D space: X, Y and Z. Click on the red circle (= X) and drag the mouse until the emitter has a rotation of approximately 45 degrees. In the upper left corner of the viewport you can see the current rotation. With the T key it is possible to scale the emitter. Click on the small yellow cube in the middle of the axis and drag the mouse until the "Sx", "Sy" and "Sz" parameters in the viewport caption show a value around 0.4. Finally, go to:
Circle01 > Node Params > Particles > Resolution > 25.0
The last node is a “Gravity” daemon. This node can be found here:
“Gravity” adds a force to the scene that acts globally. This means that it is not restricted to a certain area or volume. The force acts everywhere in the scene with exactly the same strength and you can place the emitter at any point in the scene without changing its properties. Now you already have everything for your first simulation. Click on the “Simulate” button and watch the particles, how they become accelerated and fall into the vase. There, they form drops and splashes and fill the object. After 200 frames, the simulations automatically stops and you can scrub the timeline back and forth to evaluate the result. Here is a screenshot from RealFlow's viewport with all scene elements:
To get an impression of the simulation in realtime, it is a good idea to create a preview. Go to the "Main Menu" and choose:
Playback > Video Preview
Now, RealFlow will go through the cached simulation data and take a screenshot from each frame. Once all frames have been captured, a preview movie will be assembled and sent to the “Movie Player”. There you can enjoy your first simulation!
If you want to have a look at the project’s directory and the stored simulation data, choose the following entry from the "Main Menu":
File > Open Project Folder...
This command opens an external window from the operating system to check whether all files have been created. The actual RealFlow file has the project’s name and the extension FLW, e.g. “Object Filling.flw”. It is important to understand the structure and hierarchy of the project’s directory, because RealFlow stores and reads files directly from these folders (some of these directories are only created in case of need):
| displacement | This is the place where all displacement maps are stored. |
| fields | Hybrido fluids work with velocity fields and you can find the associated data files here. |
| images | Wetmap and foam-map sequences can be found here. |
| initialState | Here, RealFlow stores all files that can be used to start simulations from previously recorded states, e.g. relaxed and calm fluid volumes. |
| meshes | Polygonal meshes from Hybrido and traditional fluid simulations can be found here. |
| particles | All particle files with the BIN (“binary”) extension. Hybrido fluid particles are stored here as well, but under a separate directory (rpc) |
| log | The log file is stored in this folder. It stores exactly the same information from RealFlow. |
| objects | This folder contains dynamics data and files for geometry/object exchange. |
| waves | RealWave cache files (RWC) can be found here, but RealWave surface deformation files (SD) are located under “objects”. |
| preview | RealFlow stores all preview-based image sequences and videos here. The folder contains three directories, called “images”, "maxwell" and “video”. “video” is also the home of a “frames” folder, where all images from automatically generated video previews will be stored. |
| foam | This folder is created automatically on demand and contains foam cache files. With activated foam-maps, another directory is created storing the textures. This directory carries the name of the related Hybrido fluid domain. |
| mist | Like foam, this directory is only created on demand. You can find the mist cache files here. |
These directories are not only important for storing RealFlow files, but also for importing simulated data into your 3D application. The “objects” folder is of special importance, because we recommended storing all exchange files you have created within this directory. By default, RealFlow looks here for SD files from external 3D applications and you do not have to browse through your hard disc. The SD format is RealFlow's standard file format for geometry and motion data. The exchange plugins, that are available for all major 3D platforms, can read and write SD files as well.
The places where you want to store the scene data are not limited to the project's folder, but they can be written anywhere onto your hard disk, or even on network drives. The according path settings and specifications can be made individually for each scene in the “Export Central” dialogue. There, it is also possible to define custom node and file names, select image formats for RealFlow's various map types and choose different export formats for your simulation data. You have all possibilities to change file paths, locations and names, but in most cases it is not necessary to do this, because RealFlow will automatically manage 99% of your export tasks by setting the correct names and saving all data to the appropriate folders.
Don’t like RealFlow's startup interface? No problem, because you can completely rearrange the GUI elements and customize the layout to your own needs. Every window can be moved to a new place and combined with other panels. The size of the viewports and windows is not fixed, but can be dynamically adjusted. It is even possible to save different layouts for reusing them later, for example for scripting, animation or general purposes.
RealFlow provides endless ways to customize the program itself and its output. Almost everything you see can be edited, changed or fit to your own needs. Of course, these possibilities make RealFlow a complex software, but you will also see that many processes are automised and that you can easily work with the pre-adjusted default settings in many cases.
Happy simulating!