COMP GRAPHICS PREFINALS

scene graph

At the heart of a 3D graphics framework is a what?

scene graph

a data structure that organizes the contents of a 3D scene using a hierarchical or tree-like structure.

tree

represents a hierarchical nature of structure in a graphical form

nodes

a tree consists of elements called what?

child nodes

The successors of a node are its?

parent

while the predecessor of a node is called its?

exactly 1

each child has how many parent?

root node

This node is the tree’s topmost node.

model matrix

The accumulated transformations applied to an object are stored as the product of the corresponding matrices, which is a single matrix called what?

model matrix

This effectively stores the current location, orientation, and scale of an object

transform

current location, orientation, and scale of an object. These three (3) are collectively referred to as the?

world transformation

can be calculated from the product of the model matrix of the object and those of each of its ancestors

world transformation

 The transform of an object relative to the root of the scene graph, often called a what?

TRUE

is it true that a scene graph structure also allows simple geometric shapes to be grouped together into a compound object that can be easily transformed into a single unit?

FALSE

Is it true that transforming the parent node does not affect the entire table object

• A matrix to store its transform data
• A list of references to child objects
• A reference to a parent object

In a scene graph framework, the nodes represent objects located in a threedimensional space. The corresponding class shall contain three (3) items:

vertex array object (VAO)

associates vertex buffers to attribute variables

vertex array object (VAO)

Each mesh shall store a reference to a what?

Attribute objects

describe vertex properties, such as position and color

Geometric objects

store texture coordinates, for applying images to shapes, and normal vectors, for use in lighting calculations.

mathematical formulas

For other shapes, such as polygons, cylinders, and spheres, the attribute data shall be calculated from what?

render settings

are the properties which are set by calling functions, such as the type of geometric primitive s (points, lines, or triangles), point size, line width, and so forth

base Material class

shall initialize dictionaries to store uniform objects and render setting data

base Material class

It shall also define functions to perform tasks such as compiling the shader program code and locating uniform variable references

1. the transformation of a mesh,

2. the transformation of the virtual camera used for viewing the scene

3. the perspective transformation applied to all objects in the scene

There are three ( 3 ) required uniform variables by most shaders whose values are stored outside the material.