Skip to main content

3D Computer Graphics



3D Computer Graphics


In the 2D system, we use only two coordinates X and Y but in 3D, an extra coordinate Z is added. 3D graphics techniques and their application are fundamental to the entertainment, games, and computer-aided design industries. It is a continuing area of research in scientific visualization.
Furthermore, 3D graphics components are now a part of almost every personal computer and, although traditionally intended for graphics-intensive software such as games, they are increasingly being used by other applications.
Parallel Projection
Parallel projection discards z-coordinate and parallel lines from each vertex on the object are extended until they intersect the view plane. In parallel projection, we specify a direction of projection instead of center of projection.
In parallel projection, the distance from the center of projection to project plane is infinite. In this type of projection, we connect the projected vertices by line segments which correspond to connections on the original object.
Parallel projections are less realistic, but they are good for exact measurements. In this type of projections, parallel lines remain parallel and angles are not preserved. Various types of parallel projections are shown in the following hierarchy.
Orthographic Projection
In orthographic projection the direction of projection is normal to the projection of the plane. There are three types of orthographic projections −
  • Front Projection
  • Top Projection
  • Side Projection
Oblique Projection
In orthographic projection, the direction of projection is not normal to the projection of plane. In oblique projection, we can view the object better than orthographic projection.
There are two types of oblique projections − Cavalier and Cabinet. The Cavalier projection makes 45° angle with the projection plane. The projection of a line perpendicular to the view plane has the same length as the line itself in Cavalier projection. In a cavalier projection, the foreshortening factors for all three principal directions are equal.
The Cabinet projection makes 63.4° angle with the projection plane. In Cabinet projection, lines perpendicular to the viewing surface are projected at ½ their actual length. Both the projections are shown in the following figure −
b
Isometric Projections
Orthographic projections that show more than one side of an object are called axonometric orthographic projections. The most common axonometric projection is an isometric projection where the projection plane intersects each coordinate axis in the model coordinate system at an equal distance. In this projection parallelism of lines are preserved but angles are not preserved. The following figure shows isometric projection −

Comments

Post a Comment

Popular posts from this blog

Education of India Part 2

History [ edit ] Main article:  History of education in South Asia The remnants of the library of  Nalanda , built in the 5th century BCE by  Gupta kings . It was rebuilt twice after invasion, first after an invasion from the  Huns  in the 5th century BCE and then after an invasion from the  Gaudas  in the 7th century CE but abandoned after the third invasion by  Turkic invaders  in the 12th century. Takshasila  (in modern-day Pakistan) was the earliest recorded centre of higher learning in India from possibly 8th century BCE, and it is debatable whether it could be regarded a university or not in modern sense, since teachers living there may not have had official membership of particular colleges, and there did not seem to have existed purpose-built lecture halls and residential quarters in Taxila, in contrast to the later Nalanda university in eastern India.  Nalanda  was the oldest university-system of education in the world in the modern sense of university. There al
Post a Comment
Read more

Save a Workbook in another File Format

  Save a Workbook in another File Format When you save an Excel 2013 Workbook, by default it saves in the  .xlsx  format. Excel 2013 supports saving in other formats, but whenever you save a workbook in another file format, some of its formatting, data, and features might not be saved. File Formats (File Types) that are supported in Excel 2013 − Excel File Formats Text File Formats Other File Formats Excel File Formats Format Extension Description Excel Workbook .xlsx The default XML-based file format for Excel 2007-2013. Cannot store Microsoft Visual Basic for Applications (VBA) macro code or Microsoft Office Excel 4.0 macro sheets (.xlm). Strict Open XML Spreadsheet .xlsx An ISO strict version of the Excel Workbook file format (.xlsx). Excel Workbook (code) .xlsm The XML-based and macro-enabled file format for Excel 2007-2013. Stores VBA macro code or Excel 4.0 macro sheets (.xlm) Excel Binary Workbook .xlsb The binary file format (BIFF12) for Excel 2007-2013. Template .xltx The defa
Post a Comment
Read more

ORGANIZATIONAL STRUCTURE OF A DEPARTMENT IN THE GOVERNMENT OF INDIA

  ORGANI
Post a Comment
Read more