/* * balls.c - Create a set of shiny spheres, with each sphere blooming sets of * 9 more spheres with 1/3rd radius. None of the spheres are clipped. A * square floor polygon is added. Three light sources. * * Version: 2.2 (11/17/87) * Author: Eric Haines, 3D/Eye, Inc. * * SIZE_FACTOR determines the number of objects output. * Total spheres = sum of n=0,SF of (9**SF). * * SIZE_FACTOR # spheres # squares * 1 10 1 * 2 91 1 * 3 820 1 * * 4 7381 1 */ #include #include #include #include "def.h" #include "lib.h" /* These may be read from the command line */ static int size_factor = 1; static int raytracer_format = OUTPUT_POVRAY; static int output_format = OUTPUT_CURVES; static COORD4 objset[9] ; /* * Output the parent sphere, then output the children of the sphere. * Uses global 'objset'. */ void output_object(depth, center, direction) int depth; COORD4 *center, *direction; { double angle; COORD4 axis, z_axis; COORD4 child_pt, child_dir; MATRIX mx; long num_vert; double scale; /* output sphere at location & radius defined by center */ lib_output_sphere(center, output_format); /* check if children should be generated */ if (depth > 0) { --depth ; /* rotation matrix to new axis from +Z axis */ if ( direction->z >= 1.0 ) { /* identity matrix */ lib_create_identity_matrix(mx); } else if ( direction->z <= -1.0 ) { lib_create_rotate_matrix(mx, Y_AXIS, PI); } else { SET_COORD(z_axis, 0.0, 0.0, 1.0); CROSS(axis, z_axis, (*direction)); lib_normalize_coord3(&axis); angle = acos((double)DOT_PRODUCT(z_axis, (*direction))); lib_create_axis_rotate_matrix(mx, &axis, angle); } /* scale down location of new spheres */ scale = center->w * (1.0 + direction->w ) ; for ( num_vert = 0 ; num_vert < 9 ; ++num_vert ) { lib_transform_coord(&child_pt, &objset[num_vert], mx); child_pt.x = child_pt.x * scale + center->x ; child_pt.y = child_pt.y * scale + center->y ; child_pt.z = child_pt.z * scale + center->z ; /* scale down radius */ child_pt.w = center->w * direction->w ; SUB3_COORD( child_dir, child_pt, (*center) ) ; child_dir.x /= scale ; child_dir.y /= scale ; child_dir.z /= scale ; child_dir.w = direction->w ; output_object(depth, &child_pt, &child_dir); } } } /* Create the set of 9 vectors needed to generate the sphere set. */ /* Uses global 'objset' */ void create_objset() { COORD4 axis, temp_pt, trio_dir[3]; double dist; MATRIX mx; long num_set, num_vert; dist = 1.0 / sqrt((double)2.0); SET_COORD4(trio_dir[0], dist, dist, 0.0, 0.0); SET_COORD4(trio_dir[1], dist, 0.0, -dist, 0.0); SET_COORD4(trio_dir[2], 0.0, dist, -dist, 0.0); SET_COORD(axis, 1.0, -1.0, 0.0); lib_normalize_coord3(&axis); lib_create_axis_rotate_matrix(mx, &axis, asin((double)(2.0/sqrt((double)6.0)))); for (num_vert=0;num_vert<3;++num_vert) { lib_transform_coord(&temp_pt, &trio_dir[num_vert], mx); COPY_COORD(trio_dir[num_vert], temp_pt); } for (num_set=0;num_set<3;++num_set) { lib_create_rotate_matrix(mx, Z_AXIS, num_set*2.0*PI/3.0); for (num_vert=0;num_vert<3;++num_vert) { lib_transform_coord(&objset[num_set*3+num_vert], &trio_dir[num_vert], mx); } } } int main(argc,argv) int argc ; char *argv[] ; { COORD4 back_color, obj_color ; COORD4 backg[5], bvec, light ; COORD4 from, at, up ; COORD4 center_pt, direction ; double radius, lscale; char *scolor, *bcolor; /* Start by defining which raytracer we will be using */ switch (argc) { case 4: output_format = atoi(argv[3]); case 3: raytracer_format = atoi(argv[2]); case 2: size_factor = atoi(argv[1]); break; defaut: break; } if (raytracer_format == OUTPUT_RTRACE || raytracer_format == OUTPUT_PLG) lib_set_raytracer(OUTPUT_DELAYED); else lib_set_raytracer(raytracer_format); lib_set_output_file(stdout); lib_set_raytracer(raytracer_format); lib_set_polygonalization(3, 3); /* set radius of sphere which would enclose entire object */ radius = 1.0 ; /* output viewpoint */ SET_COORD(from, 2.1, 1.3, 1.7); SET_COORD(at, 0.0, 0.0, 0.0); SET_COORD(up, 0.0, 0.0, 1.0); lib_output_viewpoint(&from, &at, &up, 45.0, 1.0, 0.01, 512, 512); /* output background color - UNC sky blue */ SET_COORD(back_color, 0.078, 0.361, 0.753); lib_output_background_color(&back_color); /* For raytracers that don't scale the light intensity, we will do it for them */ lscale = (raytracer_format == OUTPUT_NFF || raytracer_format == OUTPUT_RTRACE ? 1.0 : 1.0 / sqrt(3.0)); /* output light sources */ SET_COORD4(light, 4.0, 3.0, 2.0, lscale); lib_output_light(&light); SET_COORD4(light, 1.0, -4.0, 4.0, lscale); lib_output_light(&light); SET_COORD4(light, -3.0, 1.0, 5.0, lscale); lib_output_light(&light); /* output floor polygon - beige */ SET_COORD(back_color, 1.0, 0.75, 0.33); lib_output_color(NULL, &back_color, 0.2, 0.8, 0.0, 0.0, 0.0, 0.0, 1.0); bvec.x = bvec.y = radius * 12.0; bvec.z = -radius / 2.0; SET_COORD(backg[0], bvec.x, bvec.y, bvec.z); SET_COORD(backg[1], -bvec.x, bvec.y, bvec.z); SET_COORD(backg[2], -bvec.x, -bvec.y, bvec.z); SET_COORD(backg[3], bvec.x, -bvec.y, bvec.z); SET_COORD(backg[4], bvec.x, bvec.y, bvec.z); lib_output_polygon(4, backg); /* set up object color - mirrored */ SET_COORD(obj_color, 1, 1, 1); lib_output_color(NULL, &obj_color, 0.0, 0.2, 0.8, 0.3, 5.0, 0.0, 1.0); /* create set of spawned points */ create_objset(); /* compute and output object */ SET_COORD4(center_pt, 0.0, 0.0, 0.0, radius / 2.0); SET_COORD4(direction, 0.0, 0.0, 1.0, 1.0/3.0); output_object(size_factor, ¢er_pt, &direction); /* Make sure everything is cleaned up */ if (raytracer_format == OUTPUT_RTRACE || raytracer_format == OUTPUT_PLG) { lib_set_raytracer(raytracer_format); lib_flush_definitions(); } }