Rastre and vector, formats. 3D

Содержание и основные понятия

By table of contents
Alterna chapter 20.2
Rastre and vector, formats. 3D
Resolution, formats, no-loss scale, basic 3D graphics.
Rastr: pixels and resolution
Grass image
- Pixel grid (points), resolution = number of pixels horizontal by vertical.
DPI
(dots per inch) is the density of pixels when printed.
Width (pixels)
Height (pixels)
DPI (printed)
Color depth (beat)
Print Size
—
Quantity (beat)
—
(MB, uncompressed)
—
MP (megapixels)
—
Example: 4,000×3000, 24 bits, 300 DPI
Print size = 4000 x 300 x 25.4 E 338x254 mm (A3). Total = 4,000 x 3000 x 24 = 288,000,000 bits ~ 34.3 MB. For 96 DPI, screen size ~ 416 x 312 pixels.
raster graphics formats
Format
Compression
Transparency
Typical size
(4,000 x 3000, 24 bits)
Application
BMP
None
—
~34.3 MB
Saved without loss, Windows
JPEG
lossy
—
3 - 8 MB
Photos, web images.
PNG-8
lossless
1 bit
5 - 12 MB
Web graphics, icons, screen shots
PNG-24
lossless
—
~25 MB
Screen shots, diagrams, art
WebP
lossy/lossless
Yes
2 - 5 MB
Web (Google), animated stickers
TIFF
optional
Yes
~ 40 MB
Professional photography, polygraphy
RAW
none
Yes
~50 MB
Digital cameras, 48-bit color
GIF
lossless
1 bit (simple)
2-10 MB
Animation, 256 color max.
Vector schedule
Vector
The text format of the SVG describes the Bézier and the filler curves.
♪ Bézier Curves
The mathematical curve described by the four points: the beginning, the end, and the two reference points. The curve goes on and on between the beginning and the end of the curve, "attracting" to the control points.
▪ Formats
SVG
==History==The Web vector is a web-based XML.
AI
— Adobe Illustrator.
EPS
- Universal to the press.
PDF
- A vector plus a ractor.
CDR
— CorelDRAW.
♪ When the vector is better
Logotypes, icons, fonts, drawings, cartographics. Photos are always ruffled: too many parts for vectorization.
Rastr vs Vector
Rastr:
An honest pixel \ is easily edited but scaled with a loss of quality (sum 4× = blur). File size = XY·i.
vector:
The formulas and curves are scalable indefinitely without loss, but not suitable for photorealism. The size of the file depends on the complexity of the scene, not the area.
🔍
Interact: scale vs vector rug
Two images: raster (pixel grid) and vector (creative), increasing the scale — trench swims, the vector will remain clear.
Rastr (bitmap)
The pixels are fixed, and in the zoom they're staged artifacts.
×1
Vector (SVG-like)
Lines and curves, in the zoom, the formulas are recalculated.
×1
Basic 3D graphics
3D Object
A set of polygons (triangles or quadrilaterals), textures (grave maps), materials and lighting is described.
Redding.
- Transforming the 3D scene into a 2D image.
♪ Polygons and messes
Mash.
===Vertices===The larger the range is the more detailed model but the larger the computations.
Human model: ~100,000 polygons. ~ 10,000.
♪ Textures and materials
Texture
is a raster image wrapped around the range.
UV-deploy
- 3D surface projection for 2D texture application.
Normal card
- simulating the topography without adding polygons.
Format
Appointment
Type
Examples
OBJ
Geometry (tops, test sites)
Text
Simple exchange, 3D seal.
STL
Surface geometry only
Text/binary
3D seal, CAD
FBX
Geometry + Animation + Materials
Binary
Unity, Unreal, Maya
glTF / GLB
Web-ready 3D (JSON + binary buffers)
JSON / Binary
Web, Three.js, Blender
BLEND
Blender format
Binary
Modeling, branding
DAE
Collada — Universal Exchange
XML
Web, game engines
Size formula (discretion, chap. 9.4)
Three-D tender per second:
I
frame
= X × Y × i × K
fps
Where i is the depth of the color, K is the number of frames per second. For 4K (3840 x 2160), 24 bits, 60 fps: I = 3840 x 2,160 x 60 x 11.9 Gbit/s, that's why you need powerful GPUs.
🎮
Interactive 3D cube (Canvas)
The rotating cube uses a turning matrix and projection of 3D ± 2D. Each edge is a polygon.
🎯
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