COMPUTER GRAPHICS PROGRAMMING - PREFINALS EXAM

the heart of a 3D graphics framework. it is a data structure that organizes the contents of a 3D scene using a hierarchical or tree-like structure

scene graph

It represents a hierarchical nature of structure in a graphical form

tree

elements

nodes

successors of a node

child nodes

predecessor of a node

parent

This node is the tree's topmost node

root node

The accumulated transformations applied to an object are stored as the product of the corresponding matrices

model matrix

The transform of an object relative to the root of the scene graph, it can be calculated from the product of the model matrix of the object and those of each of its ancestors

world transformation

· A matrix to store its transform data

· A list of references to child objects

· A reference to a parent object

The corresponding class (ex. Object3D class) shall contain three (3) items:

Root node

(Scene)

Interior nodes used for grouping purposes

(Group)

Nodes corresponding to objects that can be rendered

(Mesh)

Virtual camera for rendering the point of view

(Camera)

Virtual light source that affects the shading and shadows

(Light)

The general shape and other vertex-related properties of each mesh

(Geometry)

The general appearance of an object

(Material)

The general initialization tasks and image rendering

(Renderer)

It associates vertex buffers (whose references shall be stored by attribute objects stored in the geometry) to attribute variables (specified by shaders stored in the material).

vertex array object (VAO)

the attribute data shall be calculated from mathematical formulas.

For other shapes, such as polygons, cylinders, and spheres

shader code, Uniform objects, and render settings

three (3) types of information related to the rendering process and the appearance of an object

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

render settings

This shall initialize dictionaries to store uniform objects and render setting data. It shall also define functions to perform tasks such as compiling the shader program code and locating uniform variable references

Material class

The rendering function in the Renderer class shall require two (2) parameters

scene object and a camera object

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

1. transformation of a mesh,

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

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