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Innovations in Vehicle Dynamics for Gaming

Sep 24, 2024

Vehicle Deformations and Vehicle System for The Matrix Awakens

Introduction

  • Speaker: Jacob Buck, Senior Technical Artist at Epic Games
  • Topic: Vehicle deformation and the vehicle system for The Matrix Awakens

Objectives

  • Create a dynamic and unique player experience through vehicle crashes.
  • Achieve physically based and unique crashes in each playthrough.

Vehicle Crash Dynamics

  • Utilize Control Rig and Chaos's vehicle system for dynamic crashes.
  • Highway Shooting Sequence Goals:
    • Explosive crashes with vehicles flipping.
    • Cascade effect when agents' cars interact with non-agent vehicles.
  • Modifications to vehicle's center of mass affect crash behavior.
  • Prototype crashes in test maps for quick iteration.
  • Timeline Node: Controls steering and center of mass adjustments.

Crash Behavior

  • Testing vehicle behavior at 70 mph for chase sequences.
  • Raising the center of mass helps achieve desired crash outcomes.
  • Use of debug view to visualize center of mass and steering input timing.
  • Adjust timing and amplitude for different crash feels.

Physics and Deformation of Vehicles

  • 14 physics bodies around vehicles act as sensors, connected via prismatic joints.
  • Unreal 5 Features:
    • Introduction of linear and angular plasticity attributes for deformation.
    • Permanent deformation upon exceeding specified limits.
  • Bumper Mechanics:
    • Bumpers break off when a force threshold is exceeded.
    • New capabilities to query and set constraint attributes in Blueprints.

Damage and Effects Mechanism

  • Vehicle Blueprints weaken attributes based on deformation and weapon damage.
  • Handling Dynamic Physics: Set All Bodies Below Physics Disabled node used for optimizing performance.
  • A skeletal mesh driven by physics asset handles environment interactions.

Control Rig Component

  • Mapping: Bones of root skeletal mesh are sources; Control Rig controls are targets.
  • Designed to accommodate different vehicle types using booleans and branch nodes.
  • Yellow spherical controls mapped to physics skeletons for visual deformations.
  • Safeguards for driver safety by limiting intrusions from deformations.

Data-Driven Approach

  • Data assets define vehicle types and behaviors for unique reactions on collision.
  • Features like crumple zones and vehicle interactions are easily tunable via data assets.
  • Events triggered based on physics body travel distance.

Vehicle Appearance and Optimization

  • Geometry Collections: Exchange between skeletal meshes and Nanite for performance.
  • Efficient management of the skin cache for ray tracing effects.
  • Use of separate LODs for exterior and interior vehicle meshes.

Visual Effects in Vehicle System

Jonathan Lindquist's Presentation

  • Focused on vehicle destruction, character dissolves, etc.
  • Leveraged UE5's effects editor (Niagara) for surface simulation and wear effects.
  • **Methodologies:
  1. Vehicle Surface Simulation:**
  • Point sampling over mesh surfaces to track wear and tear.
  • Collision detection via bounding volume hierarchy.

Tension Mapping

  • Used for displaying deformation and wear over time.
  • Achieved through a topology-agnostic approach.

Real-Time Effects and Performance Optimization

  • Explored GPU raycasting for collision detection.
  • Runtime adjustments via material parameter collections for visual fidelity.

Bridge Destruction Sequence Overview

Jack Oakman's Presentation

  • Objective: Create a cinematic-scale bridge destruction sequence.
  • Techniques Used:
    • Cached simulations for deterministic results in a dynamic environment.
    • Structured bridge components for staggered collapse.
    • Use of modeling tools to create fracture patterns and internal structures.

Effects Animation

Matt Radford's Presentation

  • Focus on pyrotechnics and explosions within the game.
  • Techniques Used:
    • Real-time fluid simulation and GPU Pyro solver for effects.
    • Camera-facing quads for smoke and fire effects.

Weapon Effects

  • Realistic weapon effects with data-driven systems for flexibility in weapon design.
  • Emphasis on satisfying player feedback when interacted with vehicles and environments.

Conclusion

  • The Matrix Awakens showcases innovations in vehicle dynamics, destruction sequences, and visual effects, made possible via Unreal Engine 5's capabilities.
  • Collaboration among a talented team helped bring unique gameplay experiences to life.