OPENGL2

Directional

A _____________ light is far, far away, it can be approximated as having the same direction from every point on our surface.

Buffer

According to the book, the recommended way to share a large buffer with the application is through use of a ___________ variable.

RGB

Data in OpenGL must be in __________ color space to be processed.

1. Create a shader object. 2. Compile your shader source into the object. 3. Verify that your shader compiled successfully.

Every shader program in your application will have to follow a certain sequence of steps for each shader object. What are the 3 steps in order?

rasterization

In the OpenGL pipeline, what is located between the vertex and fragment shading stages?

point

Lamps, street lights and ceiling lights that are near the scene or within the scene are ___________ lights.

framebuffer

The _______________ is composed of a rectangular array of pixels that are capable of displaying a tiny square of color at that point in the image.

built-in variable, user variable, function return value

What 3 things can a precise qualifier be applied to?

color, depth and stencil

What 3 types of buffers are available with OpenGL?

gradient

A vector directed along the directional-derivative of a function is referred to as a(n) _____________ vector.

Color

In OpenGL, you usually do all your drawing to the _______ buffer.

#version

No matter what shading stage you are programming for you will always start the structure with what line of code?

supersampling

Performing full per-sample rendering for multiple samples per pixel, and then coloring the pixel based on the average of the colors found for each sample in the pixel is referred to as_____________

False

(T/F) A texture that contains normal perturbation values for the purpose of bump mapping is called a perturbed map.

True

(T/F) OpenGL automatically clips geometry against the near and far planes as well as the viewport.

False

(T/F) OpenGL does not have the commands to support rendering a scene through multiple viewports.

False

(T/F) Point sampling and area sampling are the same thing.

True

(T/F) Skewing is a linear transformation.

False

(T/F) Textures generated by stored texture shaders have no fixed area or resolution.

False

(T/F) Textures generated procedurally have very high memory requirements compared with stored textures

True

(T/F) The classic lighting model adds up a set of independently computed lighting components to get a total lighting effect for a particular spot on a material surface.

True

(T/F)Data is copied into shaders from OpenGL through the "in" data type variables.

True

(T/F)GLSL is a typed language, meaning every variable must be declared and have an associated type.

False

(T/F)GLSL supports 2D and 3D vectors only

True

(T/F)Multisampling and antialiasing are the same thing.

False

(T/F)The color buffer is the only buffer that holds information about a pixel.

True

(T/F)The real work in a shader is done by computing values and making decisions.

False

(T/F)The stencil buffer keeps track of the distance between the viewpoint and the object occupying a pixel.

False

(T/F)Type conversions apply to everything, including arrays and structures.

pulse train

A sequence of pulses—usually equally spaced—used in procedural shading techniques is sometimes referred to as a(n)___________

It is like half-toning in newspapers where you can show shades of gray with combinations of black and white dots.

Explain the term dithering.

You model the illumination as two hemispheres

Explain the term hemisphere lighting.

at least once per frame

How often should you clear out buffers in OpenGL?

attenuation

The property of light that describes how a light's intensity diminishes over distance is referred to as ____________

1. Scissor test 2. Multisample fragment operations 3. Stencil test 4. Depth test 5. Blending 6. Dithering 7. Logical operations

There is a set of 7 tests that a fragment has to pass prior to going into the framebuffer. List these tests in order.

Procedural texture shaders require the algorithm to be encoded in a program. Not everyone has the technical skills needed to write such a program, whereas it is fairly straightforward to create a 2D or 3D texture with limited technical skills. • Performing the algorithm embodied by a procedural texture shader at each location on an object can take longer than accessing a stored texture. • Procedural texture shaders can have serious aliasing artifacts that can be difficult to overcome. Today's graphics hardware has built-in capabilities for antialiasing stored textures (e.g., filtering methods and mipmaps). • Because of differences in arithmetic precision and differences in implementations of built-in functions such as noise, procedural texture shaders could produce somewhat different results on different platforms.

What are 2 disadvantage of using procedural shaders over stared textures?

s,t,p,q

What component accessors are associated with texture coordinates?

discards the current fragment and ceases shader execution

What does the GLSL discard flow-control statement do?

Things that would be artwork in the real world

What does the book say is a good reason to use stored textures over procedural textures?

A vector perpendicular to both a surface tangent vector and the surface normal vector.

What is a binormal?

The weighted average of a function over a specified interval

What is a convolution?

A texture map that contains information relating to the locations of shadows within a scene.

What is a shadow map?

An illumination technique that uses an image of the light falling on an object to illuminate the object.

What is image-based lighting?

programmability

What is the key to procedurally defining all sorts of texture patterns?

#pragma STDGL invariant (all)

What line of code, used in debugging, will impose invariance on all varying variables in a shader?

Comma

What operator comes last in the GLSL order of operations?

sampler types, image types, and atomic counter types

What types of variables are considered to be opaque types?

in fragment programs

When is the discard statement available to use?

Double Buffering

When you make the main color buffer have a front buffer that's displayed in your window; and a back buffer that is used to render the new image, this is referred to as what?

Uniform

Which type modifier specifies that the value is passed to the shader from the application and is constant across a given primitive?

orthographic

With ________ projection, the viewing volume is a box.

Specular

____________ highlighting is light reflected directly by the surface.

Transparent

_____________ variable types have their internal form exposed so the shader code assumes what they look like internally.

Diffuse

______________ light is light scattered by the surface equally in all directions for a particular light source.

bump

_______________ mapping involves modulating the surface normal before lighting is applied.

ambient

_________________ light is light not coming from any specific direction.

linear

_______transformations are composable.