CSE 3541
Real-time vs offline graphics pipelines? - ANS-real-time must generate the frames fast, offline
just saves the frame to disk and play them back in the future
real-time - something like gaming
movie industry uses offline
Animation definition - ANS-control of motion, involves time and can involve the camera moving,
or the camera being still and objects moving, or both camera and objects moving
Panning - ANS-When the objects are still and the camera is moving
What are the two types of Procedural technique to animation - ANS-physically based
behaviorally based
Data-driven technique to animation - ANS-EX: motion capture, capture motion from real world
and then attach this recorded motion to a virtual character
capture motion in real world and apply to computer animation
artist-driven technique to animation - ANS-Artist draws the frames
Physically based technique to animation - ANS-Involves solving physics equations, need
program to define motion, and its computationally expensive
Keyframing - ANS-Drawing some of the key/important frames and other artists will draw the
in-between frames
Rotoscoping - ANS-a technique using recorded real figures and action as a basis for drawing
individual animation frames
What is rotoscoping considered? data or artist driven? - ANS-Both, person is drawing the frame,
but we are using footage to help with drawing
Thaumatrope - ANS-A disk with a picture on each side is attached to two pieces of string. When
the strings are twirled quickly between the fingers the two pictures appear to blend into one due
to the persistence of vision.
zeotrope - ANS-a 19th-century optical toy consisting of a cylinder with a series of pictures on the
inner surface that, when viewed through slits with the cylinder rotating, give an impression of
continuous motion.
,Scalar - ANS-A physical quantity that has magnitude only.
temperature, color, etc
Additive Identity - ANS-a + 0 = a
Multiplicative Identity - ANS-a x 1 = a
Additive inverse - ANS-a+(-a)=0
multiplicative inverse - ANS-a*a^(-1)=1
Matrix nxm in size has how many rows and columns - ANS-n rows and m columns
column matrix - ANS-matrix with only one column
Vector - ANS-quantity with magnitude and direction
The number of components in a vector defines its ___________ - ANS-dimension
vector + vector = - ANS-vector
multiplying a vector by a scalar produces? - ANS-a vector, it will increase/decrease length or
reverse direction if negative
What does the dot product represent? - ANS-Proportional to the length (magnitude) of the
projection of v onto w
Cross product - ANS-finds vector perpendicular to a plane
Understand the difference between left and right-hand coordinate space - ANS-Good approach
is let your thumb be the x-axis, index finger points up for y-axis and middle finger points forward
for z-axis. If you have it so your middle finger points away from you, the x-axis (thumbs) point in
opposite directions, if you turn your hand so your thumbs point in the same direction, then your
middle fingers (z-axis) point in opposite directions
normal vector - ANS-vector with length 1
orthogonal vectors - ANS-all vectors are right angles to each other
Orthonormal basis - ANS-A basis that is an orthogonal set of unit vectors. (vector length of 1
and all vectors are at 90 deg angle)
point vs vector - ANS-point is a fixed location in geometric space, with respect to a reference
vector is just a magnitude and direction, not in a fixed location ( no reference frame needed)
, point - point = - ANS-vector
point + vector = - ANS-point
List what each of these operations changes:
translate
rotate
scale - ANS-translate - changes posiiton
rotate - change orientation
scale - change size
Does transformation order matter (say you need to rotate and translate) - ANS-Yes, Unity by
default applies transformations to local space
typically you want to translate then rotate
Unity applies transforms to the local or world space by default? - ANS-local space
Procedural modeling - ANS-automatic model creation with algorithms to perform the modeling
task:
example - creating a maze, making natural scenes (a forest), building plants (L-System)
How does procedural maze generation work? - ANS-Start with a maze with all walls, then add
open space (remove walls) For a good maze, we shouldn't have any loops or inaccessible areas
What is the perfect maze defined as? - ANS-Maze with no loops and no inaccessible areas
All perfect mazes are minimum spanning trees on the dual graph
How do we take a grid and convert it into a maze - ANS-The grid is a matrix of booleans, if true
it means there is a wall and if false it means open path
The grid is represented by a graph, a path between two nodes means that they are connected
with an open path, no path means there is a wall. A that goes straight through a cell means it is
a straight path, 90 degree turn means 90 degree turn in the maze, and so on.
dual graph - ANS-We use it to define a pathway through a grid.
Given graph A, define graph B. Each node of graph B is at the center of the graph cells of A
A graph cell is the empty enclosed space between connected vertices in A.
Now define edges in B such that each edge crosses one of graph A's edges
spanning tree - ANS-A subgraph of a graph which includes all the vertices of the graph and is
also a tree.
Means it may not contain all the original edges
Real-time vs offline graphics pipelines? - ANS-real-time must generate the frames fast, offline
just saves the frame to disk and play them back in the future
real-time - something like gaming
movie industry uses offline
Animation definition - ANS-control of motion, involves time and can involve the camera moving,
or the camera being still and objects moving, or both camera and objects moving
Panning - ANS-When the objects are still and the camera is moving
What are the two types of Procedural technique to animation - ANS-physically based
behaviorally based
Data-driven technique to animation - ANS-EX: motion capture, capture motion from real world
and then attach this recorded motion to a virtual character
capture motion in real world and apply to computer animation
artist-driven technique to animation - ANS-Artist draws the frames
Physically based technique to animation - ANS-Involves solving physics equations, need
program to define motion, and its computationally expensive
Keyframing - ANS-Drawing some of the key/important frames and other artists will draw the
in-between frames
Rotoscoping - ANS-a technique using recorded real figures and action as a basis for drawing
individual animation frames
What is rotoscoping considered? data or artist driven? - ANS-Both, person is drawing the frame,
but we are using footage to help with drawing
Thaumatrope - ANS-A disk with a picture on each side is attached to two pieces of string. When
the strings are twirled quickly between the fingers the two pictures appear to blend into one due
to the persistence of vision.
zeotrope - ANS-a 19th-century optical toy consisting of a cylinder with a series of pictures on the
inner surface that, when viewed through slits with the cylinder rotating, give an impression of
continuous motion.
,Scalar - ANS-A physical quantity that has magnitude only.
temperature, color, etc
Additive Identity - ANS-a + 0 = a
Multiplicative Identity - ANS-a x 1 = a
Additive inverse - ANS-a+(-a)=0
multiplicative inverse - ANS-a*a^(-1)=1
Matrix nxm in size has how many rows and columns - ANS-n rows and m columns
column matrix - ANS-matrix with only one column
Vector - ANS-quantity with magnitude and direction
The number of components in a vector defines its ___________ - ANS-dimension
vector + vector = - ANS-vector
multiplying a vector by a scalar produces? - ANS-a vector, it will increase/decrease length or
reverse direction if negative
What does the dot product represent? - ANS-Proportional to the length (magnitude) of the
projection of v onto w
Cross product - ANS-finds vector perpendicular to a plane
Understand the difference between left and right-hand coordinate space - ANS-Good approach
is let your thumb be the x-axis, index finger points up for y-axis and middle finger points forward
for z-axis. If you have it so your middle finger points away from you, the x-axis (thumbs) point in
opposite directions, if you turn your hand so your thumbs point in the same direction, then your
middle fingers (z-axis) point in opposite directions
normal vector - ANS-vector with length 1
orthogonal vectors - ANS-all vectors are right angles to each other
Orthonormal basis - ANS-A basis that is an orthogonal set of unit vectors. (vector length of 1
and all vectors are at 90 deg angle)
point vs vector - ANS-point is a fixed location in geometric space, with respect to a reference
vector is just a magnitude and direction, not in a fixed location ( no reference frame needed)
, point - point = - ANS-vector
point + vector = - ANS-point
List what each of these operations changes:
translate
rotate
scale - ANS-translate - changes posiiton
rotate - change orientation
scale - change size
Does transformation order matter (say you need to rotate and translate) - ANS-Yes, Unity by
default applies transformations to local space
typically you want to translate then rotate
Unity applies transforms to the local or world space by default? - ANS-local space
Procedural modeling - ANS-automatic model creation with algorithms to perform the modeling
task:
example - creating a maze, making natural scenes (a forest), building plants (L-System)
How does procedural maze generation work? - ANS-Start with a maze with all walls, then add
open space (remove walls) For a good maze, we shouldn't have any loops or inaccessible areas
What is the perfect maze defined as? - ANS-Maze with no loops and no inaccessible areas
All perfect mazes are minimum spanning trees on the dual graph
How do we take a grid and convert it into a maze - ANS-The grid is a matrix of booleans, if true
it means there is a wall and if false it means open path
The grid is represented by a graph, a path between two nodes means that they are connected
with an open path, no path means there is a wall. A that goes straight through a cell means it is
a straight path, 90 degree turn means 90 degree turn in the maze, and so on.
dual graph - ANS-We use it to define a pathway through a grid.
Given graph A, define graph B. Each node of graph B is at the center of the graph cells of A
A graph cell is the empty enclosed space between connected vertices in A.
Now define edges in B such that each edge crosses one of graph A's edges
spanning tree - ANS-A subgraph of a graph which includes all the vertices of the graph and is
also a tree.
Means it may not contain all the original edges
