k3d/share/shaders/k3d_brushedmetal2.sl:12: *  then assume specspread is roughness, then you have something 
k3d/share/shaders/k3d_castucco.sl:12: *   octaves - how many octaves of fBm to sum
k3d/share/shaders/k3d_ceramictiles.sl:61: * and the width and height of the grooves between tiles (assuming that
k3d/share/shaders/k3d_checkerboard_solid.sl:17:	float x, y, z, sum;
k3d/share/shaders/k3d_checkerboard_solid.sl:25:	sum = mod(x + y + z, 2.0);
k3d/share/shaders/k3d_checkerboard_solid.sl:26:	if(sum >= 0.5)
k3d/share/shaders/k3d_corktile.sl:46:		/* 	the pattern is built up of the sum of two offset noise functions, perturbed slightly
k3d/share/shaders/k3d_cyclone.sl:19:  float l, o, a, i;		/* Loop control for fractal sum */
k3d/share/shaders/k3d_eyeball.sl:89:   * of the whites.  The veining pattern is essentially summed zero sets
k3d/share/shaders/k3d_gmarbtile_polish.sl:49:  float turbsum, turb;
k3d/share/shaders/k3d_gmarbtile_polish.sl:81:  turbsum = 0;
k3d/share/shaders/k3d_gmarbtile_polish.sl:89:      turbsum += (1 - turbsum) * turb;
k3d/share/shaders/k3d_gmarbtile_polish.sl:92:  turbsum *=
k3d/share/shaders/k3d_gmarbtile_polish.sl:96:  Ct = mix(Ct, veincolor, turbsum);
k3d/share/shaders/k3d_granite.sl:13:	float sum = 0;
k3d/share/shaders/k3d_granite.sl:17:		sum = sum + abs(.5 - noise( 4 * freq * I))/freq ;
k3d/share/shaders/k3d_granite.sl:20:	Ci = Cs * sum * (Ka + Kd * diffuse(faceforward( normalize(N), I )) ) ;
k3d/share/shaders/k3d_greenmarble.sl:36:  float turbsum, turb, i;
k3d/share/shaders/k3d_greenmarble.sl:56:  turbsum = 0;
k3d/share/shaders/k3d_greenmarble.sl:63:      turbsum += (1 - turbsum) * turb;
k3d/share/shaders/k3d_greenmarble.sl:66:  turbsum *=
k3d/share/shaders/k3d_greenmarble.sl:69:  Ct = mix(Ct, veincolor, turbsum);
k3d/share/shaders/k3d_hair.sl:25:			/* We multipled by v to make it darker at the roots.  This assumes v=0 at the root, v=1 at the tip.  */
k3d/share/shaders/k3d_hextile.sl:10: *    (presumably due to water or something), which darkens the tile or
k3d/share/shaders/k3d_mysky.sl:21: *    threshold - fBm sum below this level is just blue sky

k3d/share/shaders/k3d_planetclouds.sl:35: *   3. The default values for the shader assume that the planet is
k3d/share/shaders/k3d_planetclouds.sl:73:  float l, o, a, i;		/* Loop control for fractal sum */
k3d/share/shaders/k3d_planetclouds.sl:74:  float result;			/* Fractal sum is stored here */
k3d/share/shaders/k3d_puffyclouds.sl:19: *    threshold - fBm sum below this level is just blue sky
k3d/share/shaders/k3d_rustymetal.sl:6: *   is basically thresholded turbulence (summed abs(snoise)).  Where it's
k3d/share/shaders/k3d_rustymetal.sl:19: *   The fractal sum used to determine the rust pattern chooses a number of
k3d/share/shaders/k3d_rustymetal.sl:20: *   octaves to sum based on the shader sampling rate.  This helps to keep
k3d/share/shaders/k3d_rustymetal.sl:55:  float i, sum = 0, a = 1;     /* Loop control for fractal sum */
k3d/share/shaders/k3d_rustymetal.sl:56:  float alimit;                /* Limit sum to do simple antialiasing */
k3d/share/shaders/k3d_rustymetal.sl:67:      sum += a * abs(snoise(PP));
k3d/share/shaders/k3d_rustymetal.sl:77:  rustiness = step (1-rusty, clamp (sum,0,1));
k3d/share/shaders/k3d_saturn.sl:22: *   Assumes being used on a sphere.  Haven't really tried it by using other
k3d/share/shaders/k3d_saturnring.sl:15: *	The default values assume that the disk has a radius of one.  If it is
k3d/share/shaders/k3d_slateroof.sl:95:	/* Work out the displacement assuming the point is in the 
k3d/share/shaders/k3d_slateroofd.sl:86:	/* Work out the displacement assuming the point is in the 
k3d/share/shaders/k3d_spacecloud.sl:73:  /* fractalsum */
k3d/share/shaders/k3d_spaceshiphull1.sl:4:float fractalsum(point Q)
k3d/share/shaders/k3d_spaceshiphull1.sl:45:  platecolor -= grime * fractalsum(P);
k3d/share/shaders/k3d_strata.sl:13: *    octaves - number of octaves of noise to sum for the turbulence
k3d/share/shaders/k3d_terran2.sl:38: *       The default values for the shader assume that the planet is
k3d/share/shaders/k3d_uberlight.sl:84: *       simplicity, the shader assumes that the texture file will
k3d/share/shaders/k3d_uberlight.sl:407:  /* For simplicity, assume that the light is at the origin of shader
k3d/share/shaders/k3d_veinedmarble.sl:48:  float turbsum;
k3d/share/shaders/k3d_veinedmarble.sl:56:  turbsum = 0;
k3d/share/shaders/k3d_veinedmarble.sl:63:      turbsum += (1 - turbsum) * turb;
k3d/share/shaders/k3d_veinedmarble.sl:68:  Ct = mix(Cs, veincolor, turbsum);
k3d/share/shaders/k3d_venus.sl:19: *    octaves - the number of octaves of noise to sum for the clouds.
k3d/share/shaders/k3d_venus.sl:23: *    The default values for the shader assume that the planet is
k3d/share/shaders/k3d_venus.sl:65:  float l, o, a, i;		/* Loop control for fractal sum */
k3d/share/shaders/k3d_venus.sl:66:  float value;			/* Fractal sum is stored here */
k3d/share/shaders/k3d_venus2.sl:21: *    octaves - the number of octaves of noise to sum for the clouds.
k3d/share/shaders/k3d_venus2.sl:67:  float l, o, a, i;         /* Loop control for fractal sum */
k3d/share/shaders/k3d_venus2.sl:68:  float value;              /* Fractal sum is stored here */
k3d/share/shaders/k3d_volcube.sl:212:    float  density_sum  = 0;
k3d/share/shaders/k3d_volcube.sl:213:    color  color_sum    = 0;
k3d/share/shaders/k3d_volcube.sl:214:    float  shad_sum     = 0;
k3d/share/shaders/k3d_volcube.sl:229:    while(curStep < numOfSteps && density_sum < 1){
k3d/share/shaders/k3d_volcube.sl:266:		density_sum += max(0,cur_density);
k3d/share/shaders/k3d_volcube.sl:267:		color_sum += clamp(cur_color,color 0, color 1);
k3d/share/shaders/k3d_volcube.sl:273:		color_sum = ( cur_color) * (1-density_sum) + color_sum;
k3d/share/shaders/k3d_volcube.sl:274:		density_sum = (cur_density) * (1-density_sum) + density_sum;
k3d/share/shaders/k3d_volcube.sl:280:		shad_sum += max(0,cur_density);
k3d/share/shaders/k3d_volcube.sl:284:		shad_sum = (cur_density) * (1-shad_sum) + shad_sum;
k3d/share/shaders/k3d_volcube.sl:286:	    if(shad_sum >= .5){
k3d/share/shaders/k3d_volcube.sl:287:		density_sum = 1;
k3d/share/shaders/k3d_volcube.sl:288:		color_sum = 1;
k3d/share/shaders/k3d_volcube.sl:301:    Ci = color_sum;
k3d/share/shaders/k3d_volcube.sl:302:    Oi = density_sum;
