Recommandé
Contenu connexe
Tendances
Tendances (20)
En vedette
En vedette (20)
Plus de vinay arora
Plus de vinay arora (20)
Dernier
Dernier (20)
CG - Output Primitives
- 1. Output Primitives Organized By: Vinay Arora Assistant Professor, CSED Thapar University, Patiala
- 2. Disclaimer This is NOT A COPYRIGHT MATERIAL Content has been taken mainly from the following books & websites: Computer Graphics C Version By Donald Hearn, M. Pauline Baker Schaum's outline of theory and problems of computer graphics By Zhigang Xiang, Roy A. Plastock Computer Graphics: Principles and Practice By James D. Foley http://en.wikipedia.org/wiki/Computer_graphics http://www.howstuffworks.com/3dgraphics.htm http://www.graphics.cornell.edu/online/tutorial/ http://www.cgarena.com/ etc… Vinay Arora CSED
- 3. Object Model Vinay Arora CSED
- 4. Primitives 2-D Drawing or a 3-D Object consist of Graphical Primitives such as Points, Lines, Circles & Filled Polygons. Graphics System or the Application Program convert each primitive from its geometric definition into a set of Pixels that make up the primitive in the Image Space. This Conversion is referred to as SCAN CONVERSION or RASTERIZATION. Vinay Arora CSED
- 5. Definitions RASTERIZATION: Process of determining which pixels provide the best approximation to a desired line on the screen. SCAN CONVERSION: Combination of rasterization and generating the picture in scan line order. Vinay Arora CSED
- 6. General Requirement Straight lines must appear as straight lines. They must start and end accurately. Lines should have constant brightness along their length. Lines should drawn rapidly. Vinay Arora CSED
- 7. Straight lines must appear as Straight Lines Vinay Arora CSED
- 8. For horizontal, vertical and 45º lines, the choice of raster elements is obvious. This lines exhibit constant brightness along the length: Vinay Arora CSED
- 9. For any other orientation the choice is more difficult: Vinay Arora CSED
- 10. Intersection Points In general Line doesn’t pass through Intersection Points. Points are very close & dense that’s why – it appears as Straight Line. We have to find Addressable Pixels. Points Distributed over the line & the most closest to the line. No Addressable Pixel is having any Floating Point number/value. Vinay Arora CSED
- 11. Jaggies Vinay Arora CSED
- 12. Staircase Effect Vinay Arora CSED
- 13. Staircase Effect Vinay Arora CSED
- 14. Direct Scan Conversion Vinay Arora CSED
- 15. DDA – Digital Differential Analyzer Vinay Arora CSED
- 16. DDA – Pseudo code Vinay Arora CSED
- 17. Section of Display Screen in case of Positive Slope Line Vinay Arora CSED
- 18. Section of Display Screen in case of Negative Slope Line Vinay Arora CSED
- 19. Screen Grid showing a Pixel in column xk on scan line yk that is to be plotted along the path of line with slope 0 < m <1 Vinay Arora CSED
- 20. Distance between pixel positions & the line y coordinate at sampling position xk+1 Vinay Arora CSED
- 21. Bresenham’s Algorithm They coordinate on mathematical line at pixel column position xk+l is calculated as Vinay Arora CSED
- 22. Bresenham’s Algorithm (Conti…) where term yk+1 - yk is either 0 or 1, depending on the sign of parameter pk. Vinay Arora CSED
- 23. Algorithm Vinay Arora CSED
- 24. Line Drawing Vinay Arora CSED
- 25. Example Vinay Arora CSED
- 26. Solution Vinay Arora CSED
- 27. Representation of Circle Vinay Arora CSED
- 28. Representation of Circle Vinay Arora CSED
- 29. Mid Point Representation Vinay Arora CSED
- 30. Mid Point Representation Vinay Arora CSED
- 31. Mid Point Circle Algo. – Basic Steps Vinay Arora CSED
- 32. Mid Point Circle Algo. – Basic Steps Vinay Arora CSED
- 33. Mid Point Circle Algo. – Basic Steps Vinay Arora CSED
- 34. Mid Point Circle Algorithm Vinay Arora CSED
- 35. Mid Point Circle Algorithm (Contd) Vinay Arora CSED
- 36. Example Vinay Arora CSED
- 37. Ellipse Vinay Arora CSED
- 38. Ellipse (Contd.) Vinay Arora CSED
- 39. General Equation Vinay Arora CSED
- 40. Scan Converting an Ellipse Vinay Arora CSED
- 41. Equation for Ellipse Vinay Arora CSED
- 42. Equation for Ellipse – For Region 1 Vinay Arora CSED
- 43. Scan Line for Polygon Filling Vinay Arora CSED
- 44. Scan Line for Polygon Filling Vinay Arora CSED
- 45. Selecting Vertex Vinay Arora CSED
- 46. Formula for Next Value for x Vinay Arora CSED
- 47. Saving Intersection Points Vinay Arora CSED
- 48. Color Boundaries for Boundary Fill Procedure Vinay Arora CSED
- 49. 4-Connected & 8-Connected Vinay Arora CSED
- 50. Boundary Fill Algorithm Vinay Arora CSED
- 51. Partially Filled in 4 - Connected Vinay Arora CSED
- 52. Boundary Fill across Pixel spans for a 4 – connected area Vinay Arora CSED
- 53. Boundary Fill across Pixel spans for a 4 – connected area Vinay Arora CSED
- 54. Flood Fill Vinay Arora CSED
- 55. Flood Fill Algorithm Vinay Arora CSED
- 56. Thnx… Vinay Arora CSED