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- Try to keep track of your cache files. The best way is to create a common folder structure where the Cinema 4D files are stored together with the simulation files. The cache folder can be adjusted under the “Scene” tree's “Cache” tab.
- RealFlow | Cinema 4D writes one particle file per "Fluid" container and frame, and one mesh file per "Mesher" container and frame.
- Both, the number and size of the files can grow quickly, so please make sure that you have enough free disk space available.
- Simulation data are not saved with the Cinema 4D project file. If you close a file without caching all previously simulated data, your results will be lost. The scene elements (emitters, daemons, etc.) will be kept, of course.
RealFlow | Cinema 4D's simulation files can become very large, and this is often seen as something negative. But, the information for 1 or 2 millions of particles have to be saved somewhere. That's a simple fact. Unfortunately, we're not able to magic away all the position, speed, or density data 
How to Cache a Simulation
- Go to Scene > Cache and specify a folder where the files will be stored.
- Click on "Cache Simulation"; a progress bar appears.
- Once the simulation is finished, the "Use Cache" checkbox will be enabled and you can scrub the timeline to see the results.
- The simulation can be interrupted at any time with "Cancel". With heavy simulations it might take a few moments until the simulation will be aborted.
- Press "Remove Cache" to delete the cache folder's content. You have to confirm this action.
File Formats
RealFlow | Cinema 4D uses the RPC format (“RealFlow Particle Cache”) for its particle files. These files are fully compatible with RealFlow's standalone version, but also with the RealFlow RenderKit and the Connectivity Plugins. Both tools are available from your customer account on realflow.com.
Meshes are stored as ABC files (Alembic). These ABCs can be loaded with Cinema 4D, RealFlow standalone, or any other application with Alembic support.