Game Design Doc
Chapter 9
Camera
Version 2.01
18/01/2006
Maintainer: Terry Greer
9 Camera 3
9.1 Camera Design Influences 4
9.2 3rd Person or 1st Person Cameras? 5
9.3 Single-Player Game Cameras 6
9.3.1. Enslaver 3rd person camera 6
Enslaver Movement in Relation to the Camera 6
Camera Movement Relative to the Enslaver 6
Colliding with Objects – Deforming the Camera Halo 7
9.3.2. Angry Cam 8
Angry Cam Controls 8
Maximum Extents 8
Height Matching 8
9.3.3. Aim Mode 9
When the Command Reticule reaches the top, bottom or sides of the screen, then the camera will move so that the reticule returns to centre screen. 9
The Enslaver will also turn left or right on the spot to follow the movement of the camera. 9
9.3.4. 1st Person Zombie Possession Camera 9
9.4 Multiplayer Game Cameras 10
9.4.1. Survivor 1st Person Camera 10
9.4.2. Enslaver 3rd Person Camera 10
9Camera
T he ultimate goal is to create an intuitive camera system, which enhances gameplay and does not impede playability or the visual aesthetic. The camera design objectives are:
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Allow the player intuitive control over the camera in combination with their character
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Ensure the camera provides a good view of the environment for strategic & visual effect
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That the camera does not impede issuing commands
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To ensure that the transition between 1st and 3rd person cameras is clear and un-confusing
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Prevent the camera from becoming hampered by objects within the environment
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Ensure that the camera does not visually compromise characters
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To enhance the playing experience with FOV effects and filters, but not complicate gameplay
9.1C amera Design Influences
Freedom Fighters
This game has provided the primary influence for the 3rd person Possession camera system. The similarities of our command system and game setting, combined with how well received the Freedom Fighter camera and control system has been, has led us to adopt an extremely similar system for Possession. The camera in Freedom Fighters works perfectly in conjunction with the rest of the 3rd person controls and allows the player to issue commands, view the terrain, move and fight without having any detrimental impact – essential for successful squad-based gameplay.
Halo (and Halo 2)
The Halo games have proved to be the primary influence for the 1st person Possession camera system. Specifically this relates to how the camera interfaces with the controls and vice versa. The success of the Halo cameras largely lies in the subtleties of the camera system. These subtleties in the camera and related control system make shooting and evading the enemy natural and intuitive. Possession will examine the Halo camera and associated control systems and will draw inspiration from the best elements, adding to them where appropriate.
9.2 3rd Person or 1st Person Cameras?
One decision that had to be made at the start was whether Possession should use a 1st or 3rd person camera.
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A 3rd person viewpoint helps the player associate with the character they are playing, but usually at the cost of accurately gauging the character’s focus of interest. Having a focus point is extremely important in games that involve accurate objective targeting: The player needs to know exactly where they are aiming, and be able to finely adjust the aim. 3rd person cameras do not generally lend themselves well to this. The character can become something of a hindrance when it obscures a player’s view (and the back of a character’s head can eventually become a boring vista).
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As the 1st person view is seen through the eyes of the player’s character, hands and feet are usually the only parts of the character that are ever seen outside of scripted events or cut-scenes. As a result 1st person cameras tend to distance a player from their character in the game. In addition, a player’s interaction with objects in the game world has little spatial feedback. This is particularly stifling in games that use close-quarters combat or adventure-style games in which the character must carefully manipulate objects and scenery to make progress.
Some games have overcome the drawbacks of each system, by using one or more perspectives at different points during the game, depending on which camera is best suited to the current situation. It’s possible to design a hybrid camera system with all the strengths and few of the weaknesses described above, and to take the burden of view selection away from the designers and players alike. Therefore Possession will use both 3rd and 1st person cameras.
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For the single-player game, the player will nominally use a 3rd person camera when in direct control of the Enslaver, but this will change to a 1st person camera when in Angry Cam mode or when possessing individual Zombie units.
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This camera system will remain exactly the same for the player controlling the Enslaver in multiplayer.
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Those players controlling Survivors will use 1st person cameras, as they control their characters in a traditional FPS manner.
9.3.1.Enslaver 3rd person camera
The camera is the combination of the input from both the Right and Left Analogue sticks
Enslaver Movement in Relation to the Camera
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Character movement is always screen-relative, not relative to the camera’s current position (i.e. you always push towards the left of the screen and the character moves that way).
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T he camera does not return to a default position when there is no input on the Left Analogue Stick, and remains in the last halo position and pitch axis until there is further input.
Camera Movement Relative to the Enslaver
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The Right Analogue Stick is used to move the camera around the Enslaver.
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The Camera Halo moves the camera along the x-axis within a “halo” that orbits the character. As a result the camera always holds the Enslaver in the centre of its view.
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Pushing left or right on the Right Analogue Stick rotates the camera around the Enslaver
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Pushing up or down on the Right Analogue Stick changes the camera’s vertical angle (in the same manner as an aircraft joystick – pulling back looks up, pushing forward looks down), automatically adjusting the pitch as necessary.
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If the Enslaver is moving forward while the camera is turning he will turn to face the camera’s new orientation (so if you rotate the camera 90 degrees to the right while the Enslaver is moving he will turn 90 degrees to the right to match it).
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As with controlling the Enslaver, camera control is always relative to the screen (so pushing right always looks to the right, irrespective of which way the Enslaver is facing).
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The Enslaver’s head, torso and waist will rotate to look at the camera’s new viewpoint. The rotation should be realistic – only the head should move, then the torso takes over as the head nears the limit of its rotation.
As the torso reaches its own limit of motion, the waist begins to turn. When stood still and the camera passes 90 degrees left or right of the Enslaver’s front then he will return to the look-ahead position whilst the camera movement may continue in a 360-degree arc around him.
Example of the Enslaver trying to match the camera’s changing direction.
The camera is rotating to the Enslaver’s right.
1 – First the Enslaver’s head matches the camera’s movement.
2 – Then the Enslaver’s torso begins to twist to match the movement.
3 – Next the Enslaver’s waist swivels to match the movement.
4 – Finally the camera’s movement has exceeded 90-degrees from the Enslaver’s facing so he returns to looking ahead and ignores the camera.
Colliding with Objects – Deforming the Camera Halo
The camera halo needs to deform so that the camera passes unimpeded around it and minimising the necessity of user input in order to correct the camera. Deformation should occur when:
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Where the camera meets with world objects and collides against them the camera halo will deform in response to the object, so that the camera passes unimpeded around it,
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Where the character presses up against an object, creating a situation where there is not enough space for the camera to pass through. The camera should stop moving along the halo when it meets the character/object.
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Part of the terrain or scenery (E.g. a wall and not simply just another object) lies between the screen and the Enslaver. However AI entities and other in-game objects may pass between the camera and the Enslaver without the camera having to compensate. Note that entities such as this may not pass through the camera itself.
9.3.2.Angry Cam
T he Angry Cam is a remote viewing camera. When activating the Angry Cam the camera viewpoint will change to that of a 1st person, out-of-body, viewpoint that is accompanied by an appropriate distortion effect. When in Angry Cam mode, the Enslaver enters a hibernation stance.
Angry Cam Controls
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The Angry Cam can be moved forwards and backwards by pressing forwards and backwards on the Left Analogue Stick.
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Pressing left or right on the Left Analogue Stick will strafe the Angry Cam accordingly.
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The Angry Cam may be turned and the height may be increased or decreased by pressing left or right, up or down, on the Right Analogue Stick accordingly.
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The Angry Cam can be ‘tilted’ up or down to look at higher or lower angles.
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When returning to the Enslaver, the Angry Cam does not simply switch back to the character, but instead is pulled back along a direct path to the Enslaver. When pulling back to the Enslaver the camera will be facing towards the Enslaver, not away from him, as this seems to offer the most dramatic results.
Maximum Extents
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The maximum extent that the Angry Cam can be raised or lowered is just above the Enslaver’s head height or just below the Enslaver’s knee.
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The Angry Cam will have a maximum range that it may be moved from the Enslaver.
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As the Angry Cam approaches the maximum range, a darkening filter will begin to activate that will increase in density as the player closes the distance to the maximum range.
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If the player reaches the maximum range the darkening density will be such that the player’s vision will be very obscured. This acts in the manner of a fog of war.
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If the maximum range is exceeded then the Angry Cam will return instantly to the Enslaver and return the player to the default 3rd person control.
Height Matching
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When activating the Angry Cam from a greater height that the ground level, the Angry Cam will quickly descend to the lower or ground level when directed over the heights edge/boundary.
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When returning, the Angry Cam will automatically ascend the height, to the Enslaver’s position, as required.
9.3.3.Aim Mode
Pressing the Right Analogue Stick (R3) activates Aim Mode.
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This mode allows the Enslaver to direct commands more specifically, and target objects at a distance.
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When entering Aim Mode the camera will quickly change to a position close to and just over the character’s right shoulder, zooming in on the environment beyond.
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The player may exit Aim Mode by re-pressing the Right Analogue Stick (R3).
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When in Aim Mode the player may still move the Enslaver using the Left Analogue Stick, although the movement speed will be greatly reduced.
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In aim mode the Command reticule isn’t fixed in the centre of the screen and can be moved about by using the Right Analogue Stick.
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When the Command Reticule reaches the top, bottom or sides of the screen, then the camera will move so that the reticule returns to centre screen.
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The Enslaver will also turn left or right on the spot to follow the movement of the camera.
9.3.4.1st Person Zombie Possession Camera
When in Angry Cam mode, the player may possess any single Zombie Unit by targeting the zombie in question and then pressing the Right Trigger.
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When possessing a Zombie Unit the camera will change to a first-person viewpoint from within that Zombie Unit’s head.
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The perspective assumed by the camera will depend on the state of the Zombie Unit being possessed.
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If the Zombie has been damaged in such a way to change the camera position or orientation, then the viewpoint will adjust accordingly.
For example: If the Enslaver possesses a Zombie Unit who has had both legs destroyed. The Zombie Unit is currently crawling along the ground in (slow) pursuit of its next meal. When the Enslaver possesses the unit, the viewpoint switches to that of the Zombie.
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The camera viewpoint will automatically be very low to the ground, emulating the damaged state of the creature.
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When viewing through the Zombie’s eyes, details of the creatures’ anatomy, such as arms, will be visible. This adds to the sensation of being inside the Zombie, but is also useful mechanically as some Zombies may be armed with weaponry, which will need to be in view.
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Firing weapons when possessing a Zombie may be difficult, as the camera will use a motion that reflects the Zombies state, making aiming tricky.
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A slightly different vision filter effect will be required for each Zombie type (Shambler, Runner, Bloater, Shredder and Monster) so that the player can tell which type of Zombie they are possessing.
Zombie Type
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Suggested Filter Effect
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Shambler
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Hazy, milky white filter – to represent the slight cataract effect
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Runner
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Angry, blood red filter
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Bloater
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Sickly, blackish-green filter
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Shredder
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Negative black and white view (so bright areas show up black and dark areas are white). Fogging effects prevent the Shredder from seeing too far. Humans show up as bright colours, with a halo around them showing their current fear level.
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Monster
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Angry, pulsating, Fiery red filter. When the Zombie roars, the fiery effect of the filter intensifies. This view will also be much higher than the other types.
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Pressing the Angry Cam button again while possessing a Zombie Unit will re-activate the Angry Cam. And / or the player may hold the Angry Cam button down to snap straight back to the default 3rd person Enslaver camera.
9.4Multiplayer Game Cameras
One of the Possession multiplayer games involves a team of Survivors attempting to fend off the Enslaver and his Zombie hordes. The Enslaver player will use the same camera and control methods of the single-player game, whereas the Survivors will play from a very traditional FPS viewpoint.
9.4.1.Survivor 1st Person Camera
The Survivor camera is a traditional console-based FPS system. The player controls the camera in precisely the same manner as the Enslaver, because the single-player control system emulates an FPS control method.
The characters arms and weaponry carried will be visible on screen, but they will not be able to see their legs or feet when looking downwards (however the character’s shadow may be visible). Whilst the camera should remain looking fixedly ahead, when reloading or performing other types of control-paused, context-related activities (such as reloading, climbing onto and off ladders, or opening doors), it would be good for the camera to follow the viewpoint of the activity.
The degree of peripheral vision will be slightly wider (70-degrees) than that of most FPS titles in order to allow the player to see further to either side of them. This extra peripheral vision, combined with surround sound, should allow the Survivor to be able to react quickly to large numbers of threats. This is especially important when the numbers of Zombies thrown against them at any one time could be very large indeed.
9.4.2.Enslaver 3rd Person Camera
The Enslaver will use the exact same single-player cameras for the multiplayer games. There will be no changes to either the camera modes or camera-related control system.
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