What is computer graphic?
The science of turning the rules of geometry and physics into (digital) pictures that mean something to people +
the formal statement of the meaning or significance of a word,phrase, idiom, etc., as found in dictionaries
an "animated corpse resurrected by mystical means, such as witchcraft"
are visual presentations on some surface, such as a wall, canvas, screen, paper, or stone to brand, inform, illustrate, or entertain.
What is computer graphic?
The science of turning the rules of geometry and physics into (digital) pictures that mean something to people +
the formal statement of the meaning or significance of a word,phrase, idiom, etc., as found in dictionaries
an "animated corpse resurrected by mystical means, such as witchcraft"
are visual presentations on some surface, such as a wall, canvas, screen, paper, or stone to brand, inform, illustrate, or entertain.
What is a vector?
A vector describes a length and a direction+
idealization of such objects
is one of the basic shapes in geometry
I do not know
What is the length of vector a?
||a|| - length of vector a+
a
|a|
5
What is a unit vector?
Unit vector is a vector of length 1+
Unit vector is a vector of length 0
There is no such vector
Just vector
What is DOT Product of 2 vectors?(select 2 options)
a .b = ||a|| * ||b|| * cosα+
a .b = xa* xb + ya * yb+
a xb = (ya*zb – za*yb,za*xb – xa*zb ,xa*yb – ya*xb)
y = m*x + b
What is Cross Product?(select 2 options)
a xb = (ya*zb – za*yb,za*xb – xa*zb ,xa*yb – ya*xb)+
|| a xb || = ||a|| * ||b|| * sinα+
a .b = ||a|| * ||b|| * cosα
a .b = xa* xb + ya * yb
Common equation of Explicit Curve Representation.
y = f(x)+
y = m*x + b
f(λ) = (x(λ), y(λ))
f(λ) = (x(λ), y(λ))
What is Explicit Representation of a 2D line?
y = m*x + b+
f(λ) = (x(λ), y(λ))
f(λ) = (x(λ), y(λ))
y = f(x)
What is equation of Parametric representation of 2D Curve?
f(λ) = (x(λ), y(λ))+
y = f(x)
y = m*x + b
y=m
Full equation of Parametric Representation of a Circle.
+
Full equation of Parametric Representation of an Ellipse.
+
Equation of tangent vector.
+
Equation of normal vector in tangent point.
+
Common equation of Implicit Curve Representation
+
Normal Vectors from the Implicit Equation.
+
Point in 2D Euclidian coordinates
+
Point in Homogeneous coordinates(select 2 options)
+
+
Coordinates of point P which located at infinity
+
What represent point at infinity in Homogeneous coordinates.
Points at infinity have their last coordinate equal to zero+
Points at infinity have their last coordinate equal to 1
Points at infinity have their last coordinate equal to 5
Points at infinity have their last coordinate equal to 6
Line equation in Homogeneous coordinates
+
Equation of The Line Passing Through 2 Points
+
Equation of Intersection Point of Two Lines
+
Common Equation of General Linear 2D Transformations
+
General form of Affine Transformations Matrix
+
Equation of “Pure” rotation
+
Equation of “Pure” translation
+
Equation of “Pure” reflection
+
Equation of “Pure” uniform scaling
+
Plane Equation in Homogeneous Coordinates
ax + by + cz +d = 0+
-ax + by + cz +d = 0
ax + by + dz +d = 0
ax - by + cz +d = 0
Equation of Elementary Rotations in 3D by
about x axis.
+
Equation of Elementary Rotations in 3D by
about y axis.
+
Equation of Elementary Rotations in 3D by
about z axis.
+
Orthographic Projection Equation in Homogeneous Coordinates
+
Equation of transformation from Canonical view to image.
+
Equation of transformation from Camera to Canonical view.
+
Equation of transformation from World to Camera
+
Equation of transformation from Object to World
+
The Perspective Projection Equations in 3D
+
Thin lens low equation.
+
Equation of parametric representation of planar patch
+
What if Polygon Mesh?
A collection of polyhedrons (vertices, edges, faces)
A collection of polygons (vertices, edges, faces)+
A collection of vertices (polygons, edges, faces)
A collection of faces (vertices, edges, polyhedrons)
Cubic Curve equation for Interpolation with Splines
P(t) = at3 + bt2 + ct
P(t) = at3 + bt2 + d
P(t) = -at3 + bt2 + ct + d
P(t) = at3 + bt2 + ct + d+
Derivative equation of Cubic Hermite Interpolation
P’(t) = 3at2 + 2bt - c
P’(t) = 3at2 + 2bt + c +
P’(t) = 3at2 - 2bt + c
P’(t) = 4at2 + 2bt + c
Hermit constraint matrix
+
Hermite basis matrix
+
Hermit basis function
+
Equation of Hermite polynomials
+
Which one is
from Hermite Basis Function
+
Which one is
from Hermite Basis Function
+
Which one is
from Hermite Basis Function
+
Which one is
from Hermite Basis Function
+
Which one is Catmull-Rom Interpolation in terms of Hermit Constrains.
+
All above
No true answer
Goal of Polygon Clipping
Remove points and parts of objects outside the view volume +
Main goal is remove surface patches that point away from the camera (backfacing patching)
Instead of deciding the depth order pixel by pixel, draw the polygons back to front. Must sort polygons in decreasing z order
Add points and parts of objects outside the view volume
Goal of Backface Culling
Remove points and parts of objects outside the view volume
Main goal is remove surface patches that point away from the camera (backfacing patching)+
Instead of deciding the depth order pixel by pixel, draw the polygons back to front. Must sort polygons in decreasing z order
Add points and parts of objects outside the view volume
Which one is Backface Culling Criterion
(p-e)*n > 0 +
(p-e)*n < 0
(p-e)*n >= 0
(p-e)*n >> 0
Which one is not Algorithm for visibility determination?
Z-Buffering
Painter’s algorithm
BSP Trees
Phong +
Which one is Z-Buffering main Idea?
Instead of deciding the depth order pixel by pixel, draw the polygons back to front. Must sort polygons in decreasing z order
Visibility determined pixel by pixel during polygon cscan-conversion+
Remove points and parts of objects outside the view volume
Add points and parts of objects outside the view volume
Which one is The Heedless Painter’s Algorithm main Idea?
Instead of deciding the depth order pixel by pixel, draw the polygons back to front. Must sort polygons in decreasing z order+
Visibility determined pixel by pixel during polygon cscan-conversion
Remove points and parts of objects outside the view volume
Add points and parts of objects outside the view volume
Which one is The Heedless Painter’s Algorithm main Idea?
A) Instead of deciding the depth order pixel by pixel, draw the polygons back to front. B) Must sort polygons in decreasing z-order.+
A) Instead of deciding the depth order pixel by pixel, draw the polygons front to back. B) Must sort polygons in decreasing z-order.
A) Do not draw anything. It is foolishly. B) Yo-ho-ho
A) Instead of deciding the depth order pixel by pixel, draw the polygons front to back. B) Must sort polygons in ascending z-order.
Which one is BSP-Tree Algorithm main Idea?
A) Maintain a data structure that allows slow computation of depth order for every eye position. B) Have mechanism to split polygons if necessary.
A) Maintain a data structure that allows fast computation of depth order for every eye position. B) Have mechanism to split polygons if necessary.+
A) Maintain a data structure that allows fast computation of depth order for every eye position. B) Have mechanism to do not split polygons if necessary.
A) Maintain a data structure that allows fast computation of depth order for every eye position. B) I am the King of the Lizards!
By the rule of Z-Buffer Algorithm, what would be the result if drew closest triangle first?
The result would be always different
There is no any result, padavan
The result would be the same+
LEROOOOOOOOOOOOOY!!!!!!!!!
Which are disadvantages of Z-Buffer Algorithm? (select 2 options)
Memory for z-buffer. Wasted computation when over-writing distant points.+
GPU for z-buffer.Wasted computation when over-writing distant points.
Memory for z-buffer.Wasted computation when creating distant points.
Memory for z-buffer.Wasted computation when computing cosines.
Which are advantages of Z-Buffer Algorithm? (select 2 options)
Simple, accurate. Independent of order polygons are drawn.+
Hard, but accurate.Independent of platform.
Do not involve your brains, idiot.
Simple, accurate. Independent of order polygons are drawn.
According The Heedless Painter’s Algorithm, how do we sort polygons that do not have a single Z-value?
Sort according to depth of farthest vertex.+
Sort according to depth of closest vertex.
Sort according to size of farthest vertex.
Do not sort! Let’s rock!
The Heedless Painter’s Algorithm: Limitations(select 2 options). Здесь непонятно, ответы совпадают с ответами в 67-м вопросе. В лекции три слайда насчет этого и только в последнем дается нормальные ответы, а не картинки с не очень четкими ответами.
Depth order depends on eye position. Correct visibilities may not be achievable w/out polygon splitting.+
Depth order does not depend on eye position. Correct visibilities may not be achievable w/out polygon splitting.
Depth order depends on left hand position. Correct visibilities may not be achievable w/out polygon splitting.
Depth order depends on eye position. Correct visibilities may not be achievable w/out polygon shading.
Main issues of Binary Space-Partitioning Trees.Опять-таки, эти ответы совпадают с ответами в 66-м. Но здесь ответы даются конкретно в слайде с описанием BSPдерева.
Depth order depends on eye position. Correct visibilities may not be achievable w/out polygon splitting.+
Depth order does not depend on eye position. Correct visibilities may not be achievable w/out polygon splitting.
Depth order depends on left hand position. Correct visibilities may not be achievable w/out polygon splitting.
Depth order depends on eye position. Correct visibilities may not be achievable w/out polygon shading.
Main idea of Supersampling
Render multiple samples for each pixel. Compute (weighted) average of samples.+
These feelings won't go away. They've been knockin' me sideways
Render one sample for each pixel. Compute (weighted) average of samples.
Render multiple samples for each pixel. Compute absolute sum of samples.
What kind of pixel grid could be? (select 2 options only from CG course)
Regular grid, Jittered grid.+
Non-regular grid, Jittered grid.
Regular grid, Very Jittered grid.
It’s Bum Bum Bigelow!
Basic idea of Keyframe Animation
Define model parameter at key frames and interpolate (often using cubic splines).+
Define model parameter at every possible frames and interpolate (often using cubic splines).
My eyes are blind, but I can see
Define model parameter and do nothing. Seriously. I do nothing. Trust me.
Basic idea of Forward Kinematics
Instead of painstakingly specifying every little motion, specify very few keyframes (or just initial & goal). Interpolations are done automatically. Or another possible answer: Specify how joints should move.+
Instead of painstakingly specifying every little motion, specify all keyframes. Interpolation are done automatically.
Би-боп-боп-бип.Арггхх. Тыуженапалубе?
Dream of Californication!!!
Basic idea of Motion Capture
Record motions of real people/objects, then transfer to digital characters.+
Record standing of real people/objects, then transfer to digital characters.
The race is run, the book is read. The end begins to show.
Record motions of almost real people/objects, then transfer to digital characters.
What is the set of points that are “reachable” by this 2-axis structure?
Афигего
Dyson Sphere
Torus+
Circle
What is rasterization?
Project geometry onto image. Compute pixel color using local shading model.+
Зачем вы вообще это учите? Идите гулять, развлекаться. Забейте на учебу.
Project geometry onto screensaver. Compute pixel color using local shading model.
Project pixels backwards onto scene. Compute pixel color using local shading model.
What is Ray tracing?
Project pixels backwards onto scene. Compute pixel color at q by estimating light reaching p directly or indirectly.+
Dear mama, you helped me write this. By showing me to give is priceless.
Project pixels backwards onto scene saver. Compute pixel brightness at q by estimating light reaching p directly or indirectly.
Project pixels forward onto image. Compute pixel color at q by estimating light reaching p directly or indirectly.
Pros of Keyframe Animation
Very expressive. Animator has full control of animation.+
Very labor intensive.Difficult to create convincing physical realism.
Very expressive. Animator has partial control of animation.
Я всеслышал!!!
What is Inverse Kinematics?
It’s the Highway to Hell!!!
Specify where character should go, then deduce joint motion.+
Specify how joints should move.
Specify the reality of this unreality in this reality of that realism.
Pros of Key-Framing with Forward Kinematics
Very easy to specify & implement.+
It is easier to say what cons do key-framing has.
Very easy to test & integrate.
Yes, Prime Minister!
Cons of Key-Framing with Forward Kinematics(select 3 options)
Often we care more about where the character should go, not how to get there. Very hard to know how to move joints of a complicated figure in order to get the desired pose (esp. in presence of obstacles.). End-effector spaces quickly become very complicated.+
Отгадайзагадку: у когодвабольшихпальца, и емунавсенасрать? БобКелсо! Приятнопознакомиться.
Often we care about how the character looks like, not how to get there. Very hard to know how to move joints of a complicated figure in order to get the desired pose (esp. in presence of obstacles.). End-effector spaces quickly become very complicated.
I see trees of green........ red roses too
The Jacobian of Inverse Kinematics
+
The Jacobian of Inverse Kinematics
О is different at each (V1, V2)->must recomputed after each step, it may not be invertible->take pseudoinverse
+
Some other answer
Some other answer
Some other answer
Equation of joint motion according Jacobian
linearization
+
Equation of en-effector according Joacobian
+
+
Which one is not Advantages of Ray Tracing
Other answer+
Which one of the steps is not from Ray Tracing: Basic Algorithm
1)cast ray r through q
2)find 1st intersection of q with scene (i.e. poit p)
3)estimate amount of light reaching p
4)estimate amount of light travelling from p to q along ray r
Some other answer+
How many algorithms of Computing Ray-Triangle Intersection(select 1 option according the course)
2+
1
3
4
General implicit Equation of Computing Ray-Quadric Intersections
+
Parametric equation of Ray-Quadric Intersections with parameter λ
+
+
Implicit form of equation of Computing Normal at a Hit Point
+
Which one is not Light Source
point source
distant source (spotlight)
extended source (aka area light source)
secondary reflection
Some other answer+
What is defuse reflection?
Represents “matte” component of reflected light, usually caused by “rough” surfaces (clay, eggshell, etc.)+
Represents shiny component of reflected light, caused by mirror-like reflection off of smooth or polished surfaces (plastics, polished metal, etc.)
Caused by materials that are not perfectly opaque. Examples include glass, water and translucent materials such as skin.
Represents the component of reflected light that scatters in the material’s interior (after transmission) before exiting again Examples include skin, milk, fog, etc.
What is Specular Reflection?
Represents shiny component of reflected light, caused by mirror-like reflection off of smooth or polished surfaces (plastics, polished metal, etc.)+
Caused by materials that are not perfectly opaque. Examples include glass, water and translucent materials such as skin.
Represents the component of reflected light that scatters in the material’s interior (after transmission) before exiting again Examples include skin, milk, fog, etc.
Represents “matte” component of reflected light, usually caused by “rough” surfaces (clay, eggshell, etc.)
What is Transmission?
Caused by materials that are not perfectly opaque. Examples include glass, water and translucent materials such as skin. +
Represents “matte” component of reflected light, usually caused by “rough” surfaces (clay, eggshell, etc.)
Represents the component of reflected light that scatters in the material’s interior (after transmission) before exiting again Examples include skin, milk, fog, etc.
Represents shiny component of reflected light, caused by mirror-like reflection off of smooth or polished surfaces (plastics, polished metal, etc.)
What is Sub-surface Scattering?
Represents the component of reflected light that scatters in the material’s interior (after transmission) before exiting again Examples include skin, milk, fog, etc.+
Caused by materials that are not perfectly opaque. Examples include glass, water and translucent materials such as skin.
Represents “matte” component of reflected light, usually caused by “rough” surfaces (clay, eggshell, etc.)
Represents shiny component of reflected light, caused by mirror-like reflection off of smooth or polished surfaces (plastics, polished metal, etc.)
The Diffuse Component of Phong model: Basic Equation for single light
+
The Diffuse Component of Phong model: General Equation
+
The Specular Component of Phong model: Basic Equation
+
Equation of ambient component from Phong model.
+
Phong Reflection: The General Equation
+
Which one is not Shading algorithm?
Flat shading
Gouraud shading
Phong shading
Smth else+
Flat shading: main Idea
Draws all triangle points p with identical color/intensity+
Makes all triangles similar to a target image
Makes all triangle as large as possible
Which one is interpolated shading?
Phong and gouraud are interpolated+
Flat is interpolated
Only gouraud is interpolated
Only phong is interpolated
Gouraud shading: main idea
Compute Li-L(bi ,ni , si ) for each vertex, Inter[plate the Li s to get value at p+
Draws all triangle points p with identical color/intensity
Interpolate bi ,ni , si to get b,n,s at p , then Compute L(b,n,s)
Smth
Phong shading: main idea
Interpolate bi ,ni , si to get b,n,s at p , then Compute L(b,n,s)+
Compute Li-L(bi ,ni , si ) for each vertex, Inter[plate the Li s to get value at p
Draws all triangle points p with identical color/intensity
Gouraud shading vs Flat shading, which one is “-”?
Specular highlights stil a problem for large triangles+
No visible seams between mesh triangles
Smooth, visually pleasing intensity variations that mask coarse geometry
Computationally less efficient (mut interpolate 3 vectors and evaluate Phong reflection model at each triangle pixel)
Phong shading vsGouraud shading, which one is “-”?
Computationally less efficient (mut interpolate 3 vectors and evaluate Phong reflection model at each triangle pixel)+
Specular highlights stil a problem for large triangles
No visible seams between mesh triangles
Smooth, visually pleasing intensity variations that mask coarse geometry
What is the “-” of Phong shading?
So in Phong Shading the attribute interpolated are the vertex normals, rather than vertex intensities. Interpolation of normal allows highlights smaller than a polygon.+
Computationally less efficient (mut interpolate 3 vectors and evaluate Phong reflection model at each triangle pixel)+
No visible seams between mesh triangles
Smooth, visually pleasing intensity variations that mask coarse geometry