M6 - Introduction to 3D Flashcards
2 Lectures - Introduction to 3D & Intro to 3D Storage
Rendering
Process of creating a 2D image from some type of data
With 2D the data is ______-based arrays of _________ colors.
pixel-based arrays of RGB colors
With 3D, the data is primarily in the form of 2 things:
Polygon data (shapes)
Vertex Data (points to make those shapes
What axis is added in 3D
The Z-axis
What is the Z-axis
forward-backward axis
(provides depth, move “into” the scene)
What kind of coordinate system do we use for 3D?
Cartesian coordinates, with the addition of the Z-axis
3D data has to be converted to _________ data
converted to PIXEL data
Everything in 3D is made of __________________.
Polygons
How many sides does a polygon need?
3
What is the visual building block of 3D?
Polygons
Does more polygons mean more detail?
Not always, a square can be formed with 200 polygons or 2, it will have the same quality
Generally speaking “less is more” when it comes to number of polygons (EXPLAIN)
You don’t want to use too many polygons because it is computing expensive. But you want to use enough to to accomplish a task. Especially when dealing with animation or deformation.
What are common side counts in polygons
3, 4, N (more than 4) typically avoided
Ultimately everything is drawn in _____________ in a process called _____________.
triangles
triangulation
Triangulation
Converting / Dividing into triangles
_________ may be the preferred “work in progress” format or structure
Quads
____________ are the “ready to be used” format
Triangles
The fundamental building block of 3D
Vertex
What are polygons made of ?
Vertex data
What does NOT ALL TRIANGULATION IS EQUAL mean?
Modern systems “auto triangulate” however these may result in undesired results. Thus manual triangulation is recommended.
What is manual triangulation?
Deciding how the polygons will triangulate opposed to letting the system auto triangulate and get undesired results.
Vertex are at a minimum a point. But what else could it contain?
position, color, normals, texture coordinates, etc
Graphics primitives
triangles, lines, and points
What is hardware optimize for?
Graphic primitives
_________________ data is sent to the graphics hardware for rendering. ____________ are the output.
Vertex (point) data
Polygons (triangles)
Convert 3D data into 2D data using __________________.
Projection
Describe Projection
The process of converting 3D data into 2D data. There is an eye and items farther away from the eye(camera) appear to be closer together.
Foreshortening
Items far from the eye(camera) appear closer together, and items closer to the camera move apart
Rasterization
Convert 2D data into pixel colors.
Generating pixel colors from polygon
Frame buffer (output)
The storage location of pixels, frame buffers are copied to the displayed device to update the image.
Explain the process
Application - This is what the program does (bulk of code)
Geometry - Convert 3D data into 2D data using PROJECTION
Rasterization - Converts 2D data into pixel colors
Frame Buffer - Storage location of pixels to be displayed to update the image
What is the camera (virtual eye)
The position from which we view a 3D scene (need at least 1)
Camera moves left? The world really moves ___________.
right
Camera moves forward? The world moves __________
back
Camera position can be fixed, static things, or ______________ positioned
dynamically
