Checker

        texture checker surface
The checker texture is perhaps the simplest texture to understand! Like all the textures it operates in three dimensions, the object's surface appearance will alternate with the object's default surface in the odd numbered "cubes" (for example between 0 & 1) and the surface specified with the texture in the even "cubes" (for example between 1 & 2).

In the example below a checker texture is altered by various transformations. Note that rotate and transform can produce some rather bizarre results.

Figure 7-3

        /*
           checker.ray
           checker example
           Stephen Peter 12 Feb 93
        */
        eyep .25 -1 19
        lookp .25 .25 0
        light .5 point  40 0 40
        light .5 point -40 0 40
        screen 300 300
        background .9 .9 .9

        surface blue
            ambient  0.2 0.2 0.5
            diffuse  0.1 0.1 0.3
            specular 0.3 0.3 0.6
            specpow 10
            reflect 0.4

        surface white
            ambient  0.3 0.3 0.3
            diffuse  0.5 0.5 0.5
            specular 0.5 0.5 0.5
            specpow 10
            reflect 0.4

        box blue -7 0.5 0  -2.5 7.5 1
            texture checker white
        box blue -2 0.5 0   2.5 7.5 1
            texture checker white  scale 1 2 1
        box blue  3 0.5 0   7.5 7.5 1
            texture checker white  scale .5 1 1
        box blue -7 -7  0  -2.5  0  1
            texture checker white  rotate 1 1 1  45
        box blue -2 -7  0   2.5  0  1
            texture checker white  transform 1 .6 0 0 1 0 0 0 1
        box blue  3 -7  0   7.5  0  1
            texture checker white  transform .5 .1 .6 .2 1 0 2 .3 1

Go to next section:
Cloud.

Return to Contents.

THE END - Notes on Rayshade - 7 - Textures - Checker