Graphics - Rendering Pipeline

Front 1

10 types of graphics primitives as defined by openGL

Back 1

1. Points
2. Lines
3. Line Strip
4. Line Loop
5. Triangles
6. Triangle Strip
7. Triangle Fan
8. Quads
9. Quad Strip
10. Polygon

Front 2

Asynchronous graphics operation

Back 2

The cpu sends graphics instructions to the gpu. The gpu executes them while the cpu continues with other tasks.

Front 3

The interface of OpenGL is called a what?

Back 3

Hardware Abstraction Layer (HAL)

Front 4

What is VRAM?

Back 4

Video Random Access Memory - the 3D graphics board's memory core

Front 5

What does the front image buffer contain?

Back 5

The pixel data visible in the viewport.

Front 6

What is the viewport?

Back 6

The area of the display containing the rendered image. May be a subregion of a window.

Front 7

How is the back image buffer used?

Back 7

The GPU renders the scene to there in its entirety before being shown to the user.

Front 8

What is a buffer swap?

Back 8

Once a scene is fully rendered, the front and back image buffers are exchanged.

Front 9

What happens when the buffer swap is not synchronized with the refresh frequency of the display?

Back 9

The artifact known as tearing. Tearing causes the upper and lower parts of the viewport to show data from different image buffers.

Front 10

What is the other name of the depth buffer?

What is the depth buffer?

Back 10

The z-buffer

The depth buffer stores, for every pixel of the image buffer, a value that represents how far away the pixel is or how deep the pixel lies in the image.

Front 11

What is the depth buffer used for?

Back 11

To perform hidden surface elimination by only allowing a pixel to be drawn if its depth is less than the depth of the pixel already in the image buffer.

Front 12

How is depth measured for the depth buffer?

Back 12

Measured as the distance from the virtual camera through which the scene is being rendered.

Front 13

What does the stencil buffer contain?

Back 13

Contains an integer mask for each pixel in the image buffer that can be used to enable or disable drawing on a per-pixel basis.

Front 14

What is the bulk of the usage of vram?

Back 14

Texture maps, images applied to the surface of an object to give greater visual detail.

Front 15

What is a bump map?

Back 15

An image map that contains vectors that represent varying slopes at different locations on an object's surface.

Front 16

The vertices of a model are generally stored in what space?

Back 16

Object space, a coordinate system local to a model and used only by that model.

Front 17

The position and orientation of objects are generally stored in what space?

Back 17

World space, a global coordinate system that ties all of the object space together.

Front 18

Before an object is rendered, it is converted into what space?

Back 18

Camera space (eye space), the space in which the x and y axes are aligned to the display and the z-axis is parallel to the viewing direction.

Front 19

What is the process of the model-view transformation?

Back 19

Transforming the vertices from object space directly into camera space by concatenating the matrices representing the transformations from object space to world space and from world space to camera space.

Front 20

What does the projection transformation do?

Back 20

It applies perspective so that geometry becomes smaller as the distance from the camera increases.

Front 21

Projection is performed in what coordinates?

Back 21

Homogeneous, four-dimensional space.

Front 22

After projection, what space are the vertices in?

Why is it called that?

Back 22

Homogeneous clip space.

So named because it is in this space that graphics primitives are clipped to the boundaries of the visible region of the scene.

Front 23

What are normalized device coordinates?

Back 23

Coordinates in which the x,y,z range falls in the range [-1,1], and reflect the final positions in which they will appear in the viewport.

Front 24

What is viewport transformation?

Back 24

Transformation that maps normalized coordinates to the actual range of pixel coordinates covered by the viewport.

Front 25

After viewport transformation, what space are the vertices in?

Back 25

After this transformation they are in window space.

Front 26

What are the 5 spaces that the vertices go through before rendering?

Back 26

1. Object
2. World
3. Camera
4. Homogeneous clip space
5. Window space

Front 27

What are the 3 transformations which vertices undergo before rendering?

Back 27

1. model-view transformation (object, world, camera)
2. Projection (homogeneous clip space)
3. Viewport transformation (window space)

Front 28

What is per-vertex lighting?

Back 28

Determining the color and intensity of light reaching each vertex and then calculating how much of that light is reflected toward the camera. The reflected color is then interpolated over the area of a graphics primitive.

Front 29

What is per-pixel lighting?

Back 29

Used to achieve highly detailed lighting interactions at every pixel covered by a graphics primitive.

Front 30

What is rasterization?

Back 30

The process of filling in the horizontal spans of pixels belonging to a primitive.

Front 31

What 4 pieces of information are contained in a fragment?

Back 31

For each pixel:
1. the depth,
2. interpolated vertex colors,
3. interpolated texture coordinates,
4. location.

Front 32

What is face culling?

Back 32

Removes either the polygons that are facing away from the camera or those facing towards the camera.

Front 33

What is backface culling?

Back 33

Face culling of polygons facing away from the camera for optimization.

Front 34

What is fragment shading?

Back 34

Also known as pixel shading, specifies how the fragment data is used to determine the final color and final depth of each pixel during rasterization.

Front 35

What is the pixel ownership test?

Back 35

The first fragment operation performed, and the only one that cannot be disabled. It determines whether a fragment lies in the region of the viewport that is currently visible on the display.

Front 36

What is the scissor test?

Back 36

Test which specifies a rectangle in the viewport to which rendering should be restricted.

Front 37

What is a scissor rectangle?

Back 37

The rectangle used in the scissor test.

Front 38

What is the alpha test?

Back 38

The test that calculates the degree of transparency associated with a fragment.

Front 39

What is the stencil test?

Back 39

This test reads the value stored in the stencil buffer at a fragment's location and compares it to a value previously specified by the application. Passes only if a specified relationship is satisfied (e.g. the stencil value is equal to a particular value).

Front 40

What is the depth test?

Back 40

Test comparing the final depth associated with a fragment to the value currently residing in the depth buffer. Normally configured so that it passes only if depth less than or equal to the value in the depth buffer. When passes, the depth buffer is updated with the depth of the fragment to facilitate hidden surface removal for subsequently rendered primitives.

Front 41

What is blending?

What are the 2 configuration options?

Back 41

Calculating a new color by combining the fragment's final color and the color already stored in the image buffer at the fragment's location. May use the fragment's alpha value and the alpha value stored in the image buffer to determine the color that ultimately appears in the viewport. May be configured to simply replace the previous color in the image buffer, or may produce a special visual effect like transparency.

Front 42

What are the 6 operations that a fragment undergoes before being written to the image buffer?

Back 42

1. Pixel Ownership Test
2. Scissor Test
3. Alpha Test
4. Stencil Test
5. Depth Test
6. Blending