1. Textures Repeated patterns Texture can be uniform or irregular Ex:fabric,soil,brick Surface finish also known as surface texture T = P 1 * V 1 * V c T= texture matrix P= light’s projection matrix V 1 = light’s projection matrix V c = camera’s view matrix

2. Textures Realism of an image is enhanced by adding surface texture to the various faces of objects Basic technique: begins with some texture fn texture(s,t) Texture space is maked off by the parameters (s,t) S = 0 to 1 T = 0 to 1 The value of texture(s,t) varies between 0 & 1 dark & light

3. Types of textures 1.Bitmap 2.Procedural

4. Bitmap textures Textures formed from bitmap representation of images Ex:digitized photo These representations consists of an array Txtr [c][r] of color values called texels C = 0 to c-1 R = 0 to r-1

5. Bitmap textures The function texture(s,t) accesses as in the code Color3 texture(Float s,Float t) { Return txtr[(int)(s*c)] [(int) (t*r)] } Color3 holds an RGB triple

6. Procedural textures We can define a texture by a mathematical function or procedure Sample coding for a spherical shape float fakesphere(float s,float t) { float r = sqrt((s-0.5)*(s-0.5) + (t-0.5)+(t- 0.5)*(t-0.5)); If(r<0.3 return 1-r/0.3 (sphere intensity) Else return 0.2 (dark background) }

7. Visible surface detection methods Based on Whether they deal with object definitions directly Or their projected images - object space methods - image space methods

8. Object space methods Compares objects and parts of objects with each other with in the scene definition to determine which surfaces should be labeled as visible

9. Image space methods Visibility is decided point by point at each pixel position on the projection plane.

10. Coordinate reference systems for texture- space,object-space,image-space Surface pattern polygons Overlaid on a layer surface polygon Processed with the parent surface

11. Texture mapping Map texture patterns on to the surfaces of objects Texture pattern - defined in a rectangular array - procedure : modifies the surface intensity values

12. Texture mapping is accomplished in two ways Method1 Map the texture patterns to object surfaces Then to the projection plane

13. Texture mapping is accomplished in two ways Method2 Map pixel areas on to the object surfaces Then to texture space

14. Rendering

15. Architectural rendering

16. graphite