Best Practices For Vehicle Controls In Unity First-Person Games
Smoother Vehicle Movement with Physics Settings
Tuning the physics properties of a vehicle such as mass, drag, and angular drag is key to achieving stable and realistic handling. A higher mass will make the vehicle feel heavier and less prone to getting pushed around. Drag will determine how quickly the vehicle slows down, with higher values leading to quicker deceleration. Angular drag specifically resists rotational motion, preventing uncontrolled spinning out.
The suspension settings like stiffness and damping have a large impact on traction and how the wheels interact with uneven terrain. Stiffer suspension withstands more force before compressing, while soft suspension is more adaptive to bumps in the road. Damping controls the rate at which the suspension compresses and decompresses. Finding the right balance is important for both vehicle performance and conveying a visceral feeling of speed to the player.
Key Points
- Increase mass for heavier feel and inertia
- Adjust linear drag for desired deceleration rate
- Higher angular drag reduces spin outs
- Stiffer suspension withstands impacts but reduces grip
- Soft suspension adapts to terrain but can bottom out
- Damping affects compression and bounce rate
Implementing Analog Input
For precise speed control, the player’s input should map to gradual throttle and brake levels rather than simple on/off states. Unity’s built-in CrossPlatformInput manager allows mapping controller axes to simulate analog pedal input. The values from these axes can scale the engine power and brake force proportionally.
Input sensitivity curves provide further fine-tuning over acceleration behavior. Exponential curves make the vehicle more responsive to small stick movements, while linear mapping gives more granular control across the axis range. Dead zones can mask unwanted minor fluctuations near the axis center.
Key Points
- Map vertical axis to throttle input
- Map horizontal axis to steering input
- Adjust input sensitivity with custom curves
- Add dead zones for stability near axis center
- Scale power and braking to axis value
Camera Sway for Immersion
As the vehicle accelerates, decelerates and steers, the gameplay camera should exhibit slight rotations and shakes to immerse the player in the motion. Quick head turns when changing direction give an exciting sense of speed. Longer sways when braking and accelerating sell the inertia of the vehicle.
Coroutines provide an easy way to introduce smooth camera animation over time. Values for rotation and shake vectors can interpolate between stable and perturbed states based on current speed and inputs. With some tuning, camera sway can substantially increase the perceived intensity and speed of the vehicle without compromising control and visibility.
Key Points
- Add camera rotation when steering left/right
- Interpolate FOV during acceleration for sense of speed
- Play subtle shake animation on bumps
- Use coroutines to animate values over time
- Tune sway amounts carefully for visibility
Audio Feedback
The sound design of vehicle audio is vital for conveying mechanical aspects and the overall driving experience. As the engine revs faster, the RPMs should match proportionally higher pitches of looped engine sounds. Skidding and wheel spin due to loss of traction can trigger additional sound effects like squealing tires.
The volume and doppler pitch shift of surface audio from contact with roads and terrain also adds realism and dimension to the vehicle’s speed and weight. These environmental audio cues connect with players on a visceral level that enhances the thrill of fast driving sequences.
Key Points
- Loop engine sounds matched to RPM
- Increase pitch based on speed
- Play skidding clips on traction loss
- Spatialize surface audio under wheels
- Doppler shift surface sounds in motion
Testing and Iteration
Smooth and responsive vehicles require continual testing, profiling, and refinement across development. Monitoring CPU/GPU usage allows identifying performance hotspots to address through optimizations. Playtesting on target platforms exposes control issues that may need tweaking based on community feedback.
As vehicles get updated over time, keeping in sync with other game systems is also critical. When tracks and terrain change, suspension and handling may need re-tuning to maintain the desired experience. Similarly, new graphical effects like advanced tire deformation can inform audio design with additional rolling and skid sounds.
Key Points
- Profile CPU/GPU usage
- Optimized expensive systems like physics
- Playtest on target devices early and often
- Gather community feedback
- Keep vehicles in sync with other systems
- Iteratively refine over development
