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| View Original: | Bump map vs isosurface2.png (1680x1050) | |||
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| Keywords: Bump map vs isosurface2.png Created with Persistence of Vision 3D computer graphics bumps wrinkles and dents can be simulated by using bump mapping A bump map changes the way an object's surface appears to reflect or refract light and can increase the realism of computer-generated images without significantly increasing render times The technique is limited in that it does not modify the shape of the underlying object in 3D-space On the left a mathematical function defining a bump map simulates a crumbling surface on a perfect sphere but the sphere's outline and shadow are unaffected On the right the same function is used to model a roughly spherical object by generating an isosurface The object's outline and shadow are therefore more realistic POV-Ray code <syntaxhighlight lang povray > version 3 6; global_settings assumed_gamma 1 0 ambient_light 0 radiosity pretrace_start 0 08 pretrace_end 0 04 count 35 nearest_count 5 error_bound 1 8 recursion_limit 3 low_error_factor 5 gray_threshold 0 0 minimum_reuse 0 015 brightness 1 adc_bailout 0 01/2 normal on media off always_sample on max_sample 1 0 fog fog_type 1 distance 9 rgb 0 turbulence 5 // ---------------------------------------- camera location <0 0 1 5 -4> direction z right x image_width/image_height look_at <0 0 0 -1 4> light_source <0 5 -3> color rgb <1 1 1> 6 area_light <3 0 0> <0 0 3> 10 10 orient circular light_source <0 100 80> color rgb <1 1 1> // ---------------------------------------- plane y -1 pigment color rgb 1 finish ambient 0 declare mytex texture pigment colour rgb <1 0 0> finish specular 0 09 roughness 0075 diffuse 85 ambient 0 reflection 0 0 include functions inc declare bump_func function f_agate x/ 5 y/ 5 z/ 5 1 declare sphere_func function x y z Radius xoff yoff zoff pow x-xoff 2 +pow y-yoff 2 +pow z-zoff 2 -pow Radius 2 isosurface function sphere_func x y z 1 0 0 0 -bump_func x y z 71 max_gradient 8 contained_by sphere 0 1 5 texture mytex translate x 1 5 sphere 0 1 texture mytex normal function bump_func x y z 10 25 accuracy 0002 bump_size 1 rotate -y 32 translate -x 1 5 </syntaxhighlight > own GDallimore 2010-10-21 thumb left earlier version with lower quality bump map Spheres Demo effects Bump mapping Ray tracing Widescreen desktop backgrounds Isosurfaces 3D test models Images with Povray source code </syntaxhighlight> | ||||
