The Full Spectrum Warrior Camera System

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The Full Spectrum Warrior Camera System

• John Giors
• Pandemic Studios, LLC

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Introduction

• Motivation
• Very important topic
• Doesnt seem to get attention
• Trial and error process
• Focus on FSW camera system
• Some general conclusions

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Road Map

• Operational overview
• Architecture
• Motion system
• Autolook
• Collision avoidance
• Debugging, tuning
• Limitations
• Recommendations future directions

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Operational Overview

• Pan and Tilt
• Zoom
• Switch teams
• Select team members

• Move target
• Collision avoidance
• Cut thru obstacle
• GPS view
• Free camera

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Architecture
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Cameras

• Multiple independent cameras
• Only one is viewed
• Useful because
• Viewing situations differ
• Simpler compared to a single camera
• Option to blend between cameras

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Implementation
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Camera Manager

• Coordinates the cameras
• Interacts with other systems

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Motion System
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Coordinate System
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Target Points

• Camera destination
• Motion controller filters the position
• Separates problems
• Choosing viewing positions
• Creating smooth motion

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The Proportional Controller (PC)

• Common technique
• Advantages
• Simple
• Nice arrival characteristic

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Disadvantages of the PC

• Abrupt exit characteristic
• Lag behind moving targets
• Tuning issue, must choose between
• Nice arrival characteristic
• Lag

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Modified Proportional Controller (MPC)

• Limits acceleration
• Controls exit characteristic
• Compensates for lag

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Limiting Acceleration
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Compensating for Lag
Vt
Vk'
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Target Point Problem

• Expect camera to lock on to target point
• However, acceleration is limited
• Sudden stop will cause overshoot

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Potential Solutions

• Allow lag?
• Smart overshoot algorithm?
• Something else?

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The FSW Solution

• Sidestep the issue
• Make target points behave reasonably
• MPC algorithm unchanged
• Inputs are improved

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Position filtering

• Examples
• Soldier position is filtered by a PC
• User inputs are smoothed

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The FSW Autolook Feature
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What is Autolook?

• Soldiers use walls and corners as cover
• Causes 50 view obstruction
• Autolook dynamically alters framing
• Reduces view obstruction

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How Autolook Works
Original centerline
Modified centerline
Obstructing object.
Camera position
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Before and After
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Collision

• Avoidance and cuts

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Normal View Collisions
Lookat object
Environment
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Flyby Collision Avoidance
Lookat object
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Lookat Avoidance
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Is Lookat Avoidance Needed?

• Highly game dependent
• Does your game use flybys?
• Does the flyby approach head-on?
• Do objects move quickly?

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Avoidance Options

• Modify the velocity
• Fly past the object, then rotate
• Change the target position
• Keep environment in mind

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Cut Through Obstacle

• Destination on other side of obstacle
• Begin flyby
• Cut at specified distance from obstruction
• Cut to unobstructed point on opposite side

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Other Camera Cuts

• Destination is beyond threshold distance
• User input detected during flyby

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Characters

• Camera does not collide with characters
• Characters become translucent

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Debugging and Tuning Aids

• Over 100 tune parameters
• Debug displays
• Raycasts
• Viewing from multiple cameras
• Input capture
• Timescale

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Field Of View (FOV)

• Aesthetics vs. usability
• FSW FOV 80 wide
• Wider than typical 60
• More information for player
• Wider than 80 is disturbing
• FOV is reduced for zoom effect

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Limitations and Improvements
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Main Camera Can Clip Walls

• Rare and temporary
• Would be nice to fix aesthetically
• Risk
• Decided to live with the issue

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Tight Spaces

• Sub-optimal playing perspective
• Tight spaces avoided by design

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Main Camera

• Very complex
• Multi-purposes
• User controls
• Flybys
• Cinematics
• Split by function

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Wrapping Up
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Recommendations, Part 1

• Usability over aesthetics
• Smooth motion (e.g., MPC)
• Avoid quick pans
• Separate user control from programmatic control
• Multiple cameras

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Recommendations, Part 2

• Visual tuning and debugging aids
• Look for alternative solutions
• Look outside the camera itself
• e.g., use translucency to avoid collisions
• Often, these are better solutions

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Future Directions

• More published works
• Integrating traditional cinematic ideas
• Volumetric environmental examination
• Better tuning/debugging feedback

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Conclusion

• Operation
• Architecture, motion system, autolook
• Collision avoidance
• Debugging and tuning
• Limitations
• Recommendations future directions

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Thanks!

• Pandemic Studios and THQ
• GDC committee
• Mark Haigh-Hutchinson
• The entire FSW team