Computer Graphics and 3D Rendering: Geometry, Pipeline, and Animation

What is the main purpose of the "Geometry" stage within the graphics pipeline?

Processing primitives and generating new geometry

What is Computer Graphics?

The field of creating images using computers.

What are the fundamental geometric units used to define 3D objects in computer graphics?

Points

Name the three primary 3D transformations used to move, resize, and orient objects in a virtual scene.

Translation, Rotation, Scaling

What is the primary role of geometry in computer graphics?

Modeling and representing 3D objects

What is a "Scene Graph" in the context of computer graphics?

A hierarchical data structure that organizes graphical objects in a scene.

In a scene graph, if you rotate a parent object, what happens to its child objects?

They rotate around the parent's center, in addition to their own transformations.

A scene graph is most commonly represented by which data structure?

A tree or a Directed Acyclic Graph (DAG)

Which of the following is a classic real-world example used to explain hierarchical transformations?

A solar system, where planets orbit the sun and moons orbit the planet.

True or False: A single node in a scene graph can only contain transformation data (translation, rotation, scale).

False

Which photoreceptor cells in the human eye are responsible for seeing in low-light conditions and do not perceive color?

Rods

The RGB color model is an example of an _________ color model, which is primarily used for digital displays.

Additive

In an RGBA color value where each channel is 8 bits (0-255), an alpha value of 0 signifies that the pixel is:

Completely transparent

An image with a color depth of 8 bits can display a maximum of how many unique colors?

256

The term "color gamut" refers to:

The complete range of colors a specific device can produce or display.

An image with a resolution of 1920x1080 is an example of a raster image. What is the fundamental building block of this type of image?

Pixel

In the standard 32-bit RGBA color model, what is the specific purpose of the 'A' channel?

To control the pixel's opacity or transparency.

A game developer wants to create a 'sniper scope' zoom effect. Which camera property should they decrease to achieve this?

Field of View (FOV)

Which type of camera projection would be most suitable for a 2D, top-down strategy game where the size of units must not change with distance to ensure fair gameplay?

Orthographic

In Virtual Reality, two images are rendered for each frame to create a sense of depth. What is this technique called?

Stereoscopic Rendering

What is the primary function of the Z-Buffer in the rendering pipeline?

To solve the problem of occlusion by storing depth information.

If a camera's Far Clip Plane is set to 100, what will happen to an object located 150 units away from the camera?

It will not be rendered.

A standard '24-bit True Color' image is composed of which channels?

Red, Green, Blue

What is the most fundamental primitive shape used to construct 3D models for the graphics pipeline?

A triangle

What is the primary output of the graphics pipeline?

A 2D array of colored pixels

Which stage of the graphics pipeline is the only one that runs on the CPU?

Application Stage

What is the main responsibility of the Vertex Shader?

To transform a vertex's 3D position into 2D screen coordinates.

The process of converting 2D shapes into a set of 'fragments' (potential pixels) is called what?

Rasterization

In which programmable stage are lighting and texturing calculations typically performed?

Fragment Shader

What is the purpose of the Depth Test (Z-buffering) in the Output Merger stage?

To solve visibility by discarding fragments that are behind other fragments at the same pixel location.

Which of the following is a fixed-function (non-programmable) stage of the pipeline?

Clipping

A developer wants to dynamically add more geometric detail to a low-polygon model when it's close to the camera. Which optional stage is best for this?

Tessellation

During rasterization, vertex attributes (like color) are smoothly blended across a triangle's surface for each fragment. What is this process called?

Attribute Interpolation

In the 3D-assisted 2D-animation pipeline (3A2A) animation pipeline, what is the primary method users employ to pose characters for animation?

Drawing multi-colored stick figures for different body parts.

Which software is considered the industry standard for professional 3D animation, known for its extensive capabilities but also its high cost and steep learning curve?

Autodesk Maya

In 3D animation, what is the process of automatically calculating the in-between frames based on animator-set keyframes called?

Interpolation

What is the key difference between Inverse Kinematics (IK) and Forward Kinematics (FK) in character animation?

FK involves animating joints from the root outwards, while IK calculates joint positions based on the end effector's target location.

In the 3D animation pipeline, the process of creating a virtual skeleton and controls for a character model is known as:

Rigging

What is the fundamental principle of the ray tracing algorithm for rendering an image?

Casting a ray from the camera through each pixel to see what it intersects in the scene.

To determine if a point on an object is in shadow, what do you do?

Cast a ray from the intersection point towards the light source to see if it's blocked.

Which component of the Phong lighting model is responsible for creating shiny highlights and depends on the camera's viewing angle?

Specular

Why is ray tracing considered computationally expensive compared to rasterization?

It requires casting and performing intersection calculations for millions of rays per frame.

What describes the fundamental difference between Indirect and Direct Volume Rendering?

Indirect Rendering first extracts a geometric surface from the data and then renders it, whereas Direct Rendering processes voxels as particles.

In the context of the Marching Cubes algorithm, what is the primary purpose of constructing a case table?

To represent the possible ways an isosurface can intersect a grid cell, based on which vertices are inside or outside the surface.

What is a significant disadvantage of isosurface extraction techniques like Marching Cubes?

The entire surface extraction process must be repeated if the user changes the isovalue threshold.

What is an "isosurface"?

A surface representing a constant value within a volume.

The Marching Cubes algorithm is an example of which rendering technique?

Indirect Volume Rendering

How is the intersection point of an isosurface with the edge of a cube typically calculated in the Marching Cubes algorithm?

Linear interpolation

What potential problem in the final mesh can arise from the 'ambiguous cases' in the Marching Cubes algorithm?

Unwanted holes or gaps in the extracted surface due to inconsistent choices between adjacent cells.