3D

From EECH Central
Jump to: navigation, search

This article is about the basic principles of a 3D environment.

3D environment

  • A 3D environment needs 3D objects.
  • A 3D environment needs textures.
    If a texture can repeat itself next to each other (like the bricks), this is called a "tileable" texture.
  • Textures are applied to the objects. This is called "texture mapping" or just mapping.
  • Rendering is the process of producing frame images from a 3D environment.
  • Rendering is processed by a 3D engine. Another engines type is a "physics engine" which compute the physics in a 3D environment. For example rag doll, this is how a dead body falls to the ground (when shot) without the use of a predetermined animated movement sequence.
A 3D object
A texture

Pixels

  • Most of the time there's a pixel overload to display on a computer screen. For example there's no need to render all pixels at distant objects. This has to be scaled down to the amount of pixels needed, this technique is called "texture filtering". Common filtering methods are:
    • anisotropic filtering
    • bilinear filtering
    • mip mapping
  • Anisotropic filtering is one of the latest filtering methods in todays graphics cards. The method is not new, but its a computing intensive process, which previous hardware couldn't handle well.
  • Bilinear filtering is not there to filter pixels, but to add pixels if the texture hasn't a sufficient amount of pixels.
  • The mip mapping technique allows the use of texture with less resolution for distant objects. This will decrease the "texture filtering" process workload, simply because it has less pixels to filter now.
  • Shaders is another method of creating good rendered images. A shader can alter mapped texture pixel's color. Light shader are very common for this purpose. It alters the brightness of a pixel to simulate shadows and highlights.
  • Bump mapping is a shader technique to create deceiving depths on a textured object.

Pixel ambiguity

The word pixel could have 3 meanings.

texture pixel a pixel on a texture map
mapped texture pixel a pixel of a texture map applied on 3D object
screen pixel a pixel on the computer screen