Scratch Flashcards
(68 cards)
1
Q
Games vs. Robots
A
Game creates world vs world creates game
Composed of sprites vs robot is sprite
Position and velocity are known vs sensed
Collisions are detected vs avoided
Goal to make world complex vs simplify the world
2
Q
Components of a game (3)
A
Stage, Sprites, Code
3
Q
Describe the Movie Metaphor
A
In a movie screen is updated 24 times a second, in a game stage is updated 30 times a second.
update is called a frame
Game is an interactive movie
4
Q
The event-driven paradigm
A
game code responds to events
5
Q
external events
A
player movement (key press, mouse click, hover)
6
Q
internal events (5)
A
start of game, frame, message, timer, sprite cloned
7
Q
event handler
A
game code that handles all aspects (behaviours) of the game
8
Q
the main loop
A
event»handle»update
9
Q
scratch script
A
responds to an event
- sequence of blocks starting on a When block
- contains: motion, control, sensing, operator, data, event
10
Q
the frame event
A
- when green flag clicked
- forever loop
- wait 0.03 seconds
- broadcast FRAME and wait
11
Q
Sprites
A
- properties (costumes, variables, scripts)
- can be characters, obstacles, projectiles, etc. etc.
12
Q
naming sprites
A
- name is for what is is
- sprites can have the same name
- sprites can only be referred to by name
13
Q
costumes
A
- sprite can change its looks by changing costume
- every sprite has at least one costume
- is a graphical representation of a sprite
- each costume has a name
14
Q
stage
A
- special sprite on which all other sprites are displayed
- has backdrops rather than costumes
- stage will always appear behind all other sprites
15
Q
intrinsic properites
A
- all sprites have properties
- is a characteristic of a sprite (position, direction, costume, size, visibility, color etc)
- sprites are manipulated by modifying properties
16
Q
extrinsic properties
A
- lives or health, difficulty of destroying an obstacle,
- often represented by numbers
- use variables
17
Q
variables
A
- location in the program, or sprite that stores a value
- referenced by name
- accessed/mutated (read and written)
- scripts associated with a sprite can access and mutate it
18
Q
cloning sprites
A
- multiple copies of a sprite
- EVERYTHING is copied
- manipulation of the clone does not affect the original
- notified when they are created (when i start as a clone)
- can be deleted (should be)
19
Q
sprite communication
A
- communicate by broadcasting messages
- messages can not be directed to a specific sprite unless only that sprite has an event handler for that particular message
20
Q
autonomous motion
A
- set sprites velocity (steps per frame)
- ## set direction
21
Q
hitting a wall
A
what to do?
- fall off edge of stage
- bounce off edge
22
Q
fall off stage
A
- hide the sprite when the x or y position goes out of bounds
- OR detect edge “if touching edge
23
Q
bouncing
A
- when sprite is touching edge, reverse velocity
- change direction 0-direction for vertical wall and 180-direction for horizontal wall
- if on edge bounce
24
Q
collision detection
A
- detects if two of more sprites are touching in some way
- cheap and fast
- expensive and slow
- fast but specialized
- complicated and fast
25
bounding box
- smallest orthogonal rectangle that can fit the sprite
26
fast and cheap
- if two bounding boxes overlap, the sprites collide
Pros: fast and cheap
Cons: can't determine which direction collision came from
-false positives
27
expensive and slow
- point based collision
- pros: more accurate than bounding box
- cons: sprites compromise many points so many checks are required
28
fast but specialized
- check bounding boxes then check point-wise
29
complicated and fast
- vector graphics are drawn using shapes
- bitmap graphics are imported pictures
- small multiple bounding boxes
30
direct mouse movement
- makes the player the mouse
- set the player sprite coordinates to the mouse coordinates
- pros: not much code
- cons: restrictions on movement may be needed, violates accepted laws of physics
31
mouse movement using easing
- gradually move avatar towards point clicked
- pros: makes physics more realistic
- cons: only allows coarse grained movement
32
implementing easing
- declaring an easing constant
- creating a transparent target
- on each frame, if avatars distance to target is greater than 1, point towards target and move an easing fraction of a distance
33
keyboard based movement
- move players with keyboard
- pros: more precise movement
- cons: requires player to learn control keys
34
implementing key controls
on frame event
| -if certain key pressed, point target in that direction
35
playtesting. what is it?
- game development method for
- getting feedback about the game
- identifying problems
- understanding how player perceive the game
- improving playability
36
playtesting involves
- players: users who are new to the game, recruited by developer
- observers: members of development team, observe players and take notes.
37
goals of playtesting
- identifying issues that affect gameplay
- bugs, playability, and understandability
- perception, feedback, improvements
38
playtesting vs user studies
-focus on a single concrete product
-passive
cheap and fast
39
external playtesting
- players are not involved with game development
- more expensive
- provides an objective view
40
internal playtesting
- game developers are the players
- cheap
- continuous view
41
before playtesting
- game must be stable
- recruit players that make up target audience
- set up 'standard' game station
42
during playtesting
- welcome/thank players
- remind player to have fun
- ask them to talk out loud while they play
- the observer must remain silent and may conduct an interview when the playtesting is over
43
role of the observer (during playtesting)
note the:
- mood of the player
- comments/suggestions
- bugs
- difficulties
- ease of learning the game
- how quickly player progresses through game
- aesthetic issues
- any additional feedback
44
after playtesting
- keep track of all players (to invite back for more playtesting)
- organize notes
- categorize observations
- address bugs and issues
- playtest again
- repeat until game is awesome
45
game elements (4)
-story
-mechanics
-technology
-aesthetics
elements work together to create a unifying theme
46
game story
- world
- characters
- quest
47
story considerations
- depth
- delivery
- pacing
48
game mechanics
use game mechanics to implement game story and support the theme
- rules
- environment
- action
- chance
- skills
49
game rules
- written rules of play
- unwritten rules
- object of the game
50
game environment
- spaces
- number of players
- physics
51
game actions
- primitive actions (privates view): moving player, shooting
| - strategic actions (generals view): protecting a zone, ambushing
52
game chance
- adds surprise
| - must retain some amount of probability
53
game skills
- physical: dexterity, coordination
- mental: memory, observation and problem solving
- social: reading and fooling opponents, coordinating with teammates
54
genre
a set of stock mechanics that are used by similar games
55
project management
-art of matching project goals, tasks and resources to accomplish a goal
56
stages of a project (7)
- defining goals
- define tasks
- determine resources
- identify risks and develop backup plans
- develop a schedule
- execute schedule
- finish and assess performance
57
projectiles
- appears initially at the player/opponent location
- moves away from initial position in a set direction
- disappears when it hits something
- causes opponent to react in some way
58
projectile life cycle (6)
- design
- initiation
- creation
- motion
- collision
- elimination
59
projectile frame script
- when i receive frame
- if i am clone then
- move 10 steps
- if am touching sprite1 then
- broadcast collision then
- delete this clone
- if touching edge then
- delete this clone
60
button states
- up
- down
- over
61
text
- static
| - dynamic
62
list
-contiguous sequence of elements
63
a polished game is
- more compelling and immersing
- likely to be played longer
- appealing to new players
64
what is game polish
-a process to reduce the number of minor issues associated with the game
65
types of game polish
- resolution of issues
- refinement of mechanics
- additional features
66
resolution of issues
- stability
- playability
- consistency
67
refinement of mechanics
- realism
- graphics
- audio
68
additional features
- special effects
- side rounds and bonus stories
- easter eggs
- special objects
