the pattern). Low values produce finely grained surfaces (sand), and high values produce coarser materials (large bumps and holes). These values do not affect blur. • Filter Length: Controls depth just recommendations from us. Figure 35.12 The Light tab The G imp Us e r’s Man u al 5 2 7 C h a p ter 3 5 MATERIALS You can specify the appearance of the rendered light to give an image or selection material characteristics between cloud shadow and sunlight, or a dull and a shiny object (0.5 -> 3.0). Figure 35.13 The Materials tab 528 T h e G i m p Us er ’ s M a n u a l L i g ht Eff ect Fil t er s Reflectivity • Diffuse