1 / 20

Introduction to constructive graphics

Introduction to constructive graphics Basic ideas - Coordinate systems - Graphics viewing pipeline “The art of 3D graphics is the art of fooling the brain into thinking that it sees a 3D object painted on a flat screen.” Coordinate systems in 3D computer graphics Left and Right handed

Thomas
Download Presentation

Introduction to constructive graphics

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Introduction to constructive graphics Basic ideas - Coordinate systems - Graphics viewing pipeline

  2. “The art of 3D graphics is the art of fooling the brain into thinking that it sees a 3D object painted on a flat screen.”

  3. Coordinate systems in 3D computer graphics • Left and Right handed • Local • 3D World • 3D Viewport • Camera

  4. 3-Dimensional coordinate systems left handed right handed Z axis goes "into" the page Z axis goes "out" of the page

  5. In this course we use left-handed coordinate system

  6. Left-handed coordinate system

  7. Local • preferred system for construction of object parts • 3D Cartesian system • Object vertices centred about the local origin Y Z X

  8. Y Y Z X Z X 3D World • 3D Cartesian coordinate system • arbitrary centre, handedness and orientation • used in the construction stage Y Z X

  9. 3D Viewport • similar to a 3D word coordinates • uses normalised 3D coordinates • used if device independence is important

  10. Camera coordinate system • used to define the view onto the 3D world that the user will see on the screen • centre (0,0,0) is located at the Imaginary User’s eye • axes oriented such that • one indicates the direction in which the User looks; • the second indicates roughly the “up” direction • the third indicates the handedness

  11. U U Y N N Z X V V

  12. U Y N Z X V 2D Window • 2D system related to screen coordinates

  13. 2D Viewport • similar to 2D Window system • uses normalised 2D coordinates • If 3D Viewport is used, the Camera will first generate 2D Viewport, which will be then converted to 2D window.

  14. Graphics viewing pipeline Graphics viewing pipeline describes a sequence of graphics operations needed to display a 3D object on a graphics device.

  15. 3D construction

  16. Viewpoint specification Viewpoint specification 3D world Y Z coordinates X

  17. Viewing volume specification Viewing volume specification 1 3D ( normalised) 1 Coordinates) Y Z 0 X 1

  18. Viewing projection Projection onto a 1 viewing surface 2D Y ( normalised) Coordinates) 0 X 1

  19. Display X 0 Display Y 2D coordinates

  20. Realistic features Realism 3D / 2D coordinates

More Related