{"id":71,"date":"2017-04-07T12:19:41","date_gmt":"2017-04-07T12:19:41","guid":{"rendered":"http:\/\/www.ruzzgames.com\/?page_id=71"},"modified":"2020-05-09T13:03:10","modified_gmt":"2020-05-09T03:03:10","slug":"3d-graphics","status":"publish","type":"page","link":"https:\/\/www.ruzzgames.com\/index.php\/3d-graphics\/","title":{"rendered":"3D Graphics"},"content":{"rendered":"

In order to display characters, rooms, outdoor environments, etc, you need to understand how 3D graphics works.<\/p>\n

3D graphics involves a lot of mathematics. This includes concepts such as vectors, trigonometry and matrices. Luckily DirectX contains mathematical functions that you can use to process and manipulate 3D graphics.<\/p>\n

\n
\n
\n
<\/header>\n
\n
\n

3D\u00a0Coordinates<\/strong><\/p>\n

The graphics in 3D is displayed as a pixel which I will also refer to\u00a0also as a point or vertex. In 2D graphics, the coordinates are referred to as\u00a0(x,y)<\/strong>\u00a0while in 3D graphics, the coordinates are referred to as\u00a0(x,y,z)<\/strong><\/p>\n

The diagram below compares 2D screen coordinates and 3D coordinates as represented by DirectX:<\/p>\n

\"\"<\/p>\n

The 3D coordinate system has an x-axis, y-axis as in the 2D system. The 3D system also includes a\u00a0z-axis<\/strong>, which goes\u00a0into<\/strong>\u00a0the screen (this is called a left-handed coordinate system). It is always hard to visualise 3D coordinates – if you stick 3 rulers together, it might be easier to visualise a point in 3D space. In the above diagram, the point (5,10,5) is obtained by travelling 5 units along the x-axis, 10 units along the y-axis and then 5 units along the z-axis (into the screen).<\/p>\n

Overview for 3D Graphics in a\u00a0game<\/strong><\/h3>\n

These topics will be explained in more detail, but I just wanted to give a brief overall picture of what is going on in 3D games, particularly in displaying 3D graphics.<\/p>\n

    \n
  1. The game universe (ie. what the player sees in a particular level) is a 3D model called a 3D scene.<\/li>\n
  2. Inside this 3D scene, objects (3D models) are placed inside.<\/li>\n
  3. The player is represented as a 3D model (eg: showing player’s hands, player’s body)<\/li>\n
  4. The game needs to take into account of the player colliding with the 3D scene or other objects, players or bots (computer driven players).<\/li>\n
  5. The computer needs to show on screen only those objects that the player can see. This needs to be done, otherwise the game will slow to a crawl. 3D computer graphics is very computer intensive, you need to take shortcuts to display the graphics with any speed. The displaying of 3D objects to the screen is called rendering.The 3D scenes and\u00a0other 3D objects\u00a0are created using 3D modeling software (eg: 3D Studio Max, Maya, Blender). The 3D objects or models are created as a mesh which has a skin or texture applied to it.<\/li>\n<\/ol>\n

    3D Primitives<\/strong><\/h3>\n

    3D graphics includes some 3D primitives – these are objects that are just basic and used to build other 3D objects.<\/p>\n

    DirectX has the following graphics primitives that are part of Direct3D graphics engine:<\/p>\n