I tried making an object float. In Blender it needed baking. In Unreal it worked instantly. That difference confused me.
This post is part of my daily learning journey in game development.
I’m sharing what I learn each day — the basics, the confusion, and the real progress — from the perspective of a beginner.
On Day 72 of my game development journey, I explored how buoyancy works differently in Blender and Unreal Engine.
What I Used to Think
Floating objects should behave the same everywhere.
If physics is physics, then water simulation should work similarly in both tools.
But when I tried it, the workflow felt completely different.
What I Realized
In Blender, floating objects usually rely on fluid simulation.
The simulation must be baked first.
This means Blender calculates the fluid behavior ahead of time and stores the result.
In Unreal Engine, buoyancy works in real time during gameplay.
Instead of simulating every water particle, Unreal approximates floating using:
- Physics forces
- Collision points
- Buoyancy calculations
This allows objects to float instantly while the game is running.
Why This Matters
Both tools solve different problems.
Blender
- Focuses on cinematic accuracy
- Uses heavier fluid simulations
- Requires baking before playback
Unreal Engine
- Focuses on real-time gameplay
- Uses simplified buoyancy physics
- Updates instantly during play
Accuracy vs performance.
Practical Fix
- Use Unreal buoyancy systems for gameplay scenarios
- Use Blender fluid simulations for cinematic shots
- Adjust mass and buoyancy values when testing floating objects
- Ensure correct collision setup for physics simulation
- Test stability with multiple objects interacting in water
Why This Matters in Real Projects
Real-time engines must prioritize performance and responsiveness. Full fluid simulations like Blender’s would be too expensive to calculate every frame during gameplay. That’s why Unreal uses simplified buoyancy calculations instead of full fluid physics.
One Lesson for Beginners
- Real-time physics differs from offline simulation
- Blender prioritizes accuracy
- Unreal prioritizes performance
- Buoyancy depends on mass and collision setup
- Choose tools based on the goal: gameplay or cinematic
Understanding this difference helped me stop expecting the same behavior from both tools.
They’re designed for different purposes.
Slow progress — but I’m building a strong foundation.
If you’re also learning game development, what was the first thing that confused you when you started?
See you in the next post 🎮🚀
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