When Water Decides to Defy Gravity
Creating a floating water sphere with that characteristic tremor seen in NASA videos is one of those effects that seems magical but has a very specific physical basis. Your intuition to use fill sphere is correct, but the strange movement you're observing is probably due to a imbalance between surface tension and other forces. The key is not to completely eliminate the movement, but to tame it to create that organic vibration you're seeking.
The second effect of a controlled opening for an internal object to emerge is more advanced, but totally achievable with the right RealFlow tools. It requires combining techniques of directed forces and emitter control to create that dramatic breaking moment.
Setup for the Floating Sphere with Vibration
Start by creating a spherical emitter with Fill Sphere activated, but instead of using zero gravity immediately, set up a very low gravity (0.1-0.3) combined with a Noise Field daemon. This approach creates a balance where the sphere maintains its general shape but has that characteristic surface tremor of water in microgravity.
The critical parameters for the Noise Field are: Strength between 2-5, Frequency around 0.5-1.0, and Scale between 0.8-1.2. This creates smooth perturbations that simulate the natural oscillations of water. The surface tension must be high (60-80) to maintain the sphere's cohesion.
- Low gravity (0.1-0.3) instead of absolute zero
- Noise Field with strength 2-5 and frequency 0.5-1.0
- High surface tension (60-80) for cohesion
- Medium viscosity (15-25) for controlled fluidity
A perfect water sphere is like a beating heart: it has constant movement but maintains its essential shape
Technique for the Emerging Object
For the object inside the sphere, first convert it to a Rigid Body with Inactive initially. This keeps the object static inside the water until you decide to activate it. Use a Trigger daemon or manually animate the change from Inactive to Active on the frame where you want the movement to begin.
The sphere opening is achieved by combining two techniques: an Attractor daemon that "pushes" the water away from the exit point, and a localized Wind daemon that creates the splash effect. The Attractor should have a small spherical shape and be activated just before the object starts moving.
- Rigid Body initially inactive
- Timed activation with Trigger daemon
- Attractor to create opening in the surface
- Localized Wind for splash effect
Precise Simulation Control
For the object exit movement, use a Gravity daemon with a custom direction or a Motor daemon applied specifically to the rigid body. This gives you absolute control over the exit trajectory and speed. The key is to perfectly synchronize the sphere's opening with the object's movement.
The parameters for collision between the object and the fluid are crucial. Increase the Collision Distance and adjust the Friction so the interaction is visible but not too violent. This creates that "push" effect where the object seems to force its way through the water.
- Motor or directional Gravity for the object
- Precise synchronization between opening and movement
- Increased collision distance for visible interaction
- Adjusted friction for realism
Optimization for Cinematic Results
For the final render, consider using Hybrido 2 as the rendering engine within RealFlow for a more cinematic look, or export the particles to your favorite rendering software. Lighting is crucial to enhance the effect - use side and back lights to highlight the water's transparency and refractivity.
In post-production, add additional foam and splash elements using RealFlow's secondary particle system. Activate Foam and Splash in the export parameters to have these elements available during compositing.
- Hybrido 2 for high-quality internal rendering
- Lighting to highlight transparency
- Export foam and splash for post-production
- Motion blur to smooth fast movements
Mastering these techniques will allow you to create everything from science fiction effects to scientifically inspired simulations with impressive realism. Because in RealFlow, even the calmest water can learn to dance to the rhythm of your daemons 😏
Recommended Setup to Get Started
Base values for the floating sphere:
Gravity: 0.2 Surface tension: 70 Viscosity: 20 Noise Field strength: 3 Noise Field frequency: 0.8 Resolution: 2.0 million particles