HardDriverz

Engine: Unreal Engine 5.5.4 (Blueprint Only)
Platform: PC
Team Size: 54
Role: Programmer
Development time: 3 months (2025/02~2025/05)

Game Description

HardDriverz is a futuristic arcade racer where players must race against each other and competitive AI in a fictional racing league to determine the best racer. The game has 3 unique and retro-techno tracks. Players can customize their karts to compete through fun, twisty, futuristic tracks that defy gravity. Pick different cool, unique power-ups that will help you get ahead of other racers as you compete to be the fastest racer.

Responsibilities

Car Physics

Designed and implemented steering and drifting mechanics with simplified physics model, creating designer-friendly parameters and providing comprehensive documentation and training

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PCG Road Tools

Developed road generation tools using Unreal PCG Framework fir spline-based mesh creation (road surfaces, railings, intersections) and built custom editor utilities for efficient spline data manipulation

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Car AI

Engineered AI manager for 4-7 opponents with frame-distributed logic for performance optimization, implemented rubber banding system, and created adaptive driving algorithms for spline-based navigation

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Car Physics

Simplified Physics Model

Debug Draw for Trajectory and Turning Radius

Designer Friendly System

Simplify physics simulation when appropriate
Parameters should be translated into designer language
Complex behavior should come from layering simple systems
Keep parameters independent

I implement lateral friction, steering, and drifting of car physics.

Unreal PCG Road Tools

Spline Road Blueprint

PCG Graph

Editor Utility (Copy or Reverse Spline Points)

Car AI

AI Manager

Control the update frequency (frequency to perceive the environment) of each AI controller to solve performance issues
Change the top speed multiplier of each AI controller according to the rubber-band system

AI Info Component

Generate a capsule collider on the parent actor with special collision preset which will block AIPerception trace.
AI controller will read the data from raycasted AI Info component.

AI Controller

Perception Layer
- Query Spline Point Transformation at a certain distance ahead
- Raycast to check obstacle in front of the AI car
Decision Layer
- Calculate the throttle, steer, brake, drift according to the spline and the obstacle detection result
- Check if the car is stuck somewhere, then decide whether to reverse.
- Choose the fork in the road
- Use a item or honk
- Choose random horizontal offset from road center
Action Layer
- Apply the input to the pawn

Rubber Banding System

Power-Based Rubber Banding

Rubber Banding Parameters

Automated AI agents enable efficient track and item validation in multiplayer racing games

Real-time AI state visualization facilitates intuitive debugging and precise tuning