I have the same object defined by recursive and by iteration. De iterative definition is much faster on rendering. Can someone provide some insight why this is ? ==== example ==== num=20; module ring(){ rotate_extrude() translate([10,0,0]) circle(r=2); } module ring_r(count,maxcount,angle) { if (count<=maxcount) { ring(); if ((count%4)==0) rotate([0,0,angle]) translate([14,0,0]) rotate([90,0,0]) ring_r(count+1,maxcount,angle); if ((count%4)==1) rotate([0,angle,0]) translate([14,0,0]) rotate([90,0,0]) ring_r(count+1,maxcount,angle); if ((count%4)==2) rotate([0,0,-angle]) translate([14,0,0]) rotate([90,0,0]) ring_r(count+1,maxcount,angle); if ((count%4)==3) rotate([0,-angle,0]) translate([14,0,0]) rotate([90,0,0]) ring_r(count+1,maxcount,angle); } } module iterative() { for (i=[0:num-1]) rotate([0,0,i*360/num]) translate([40,0,0]) rotate([0,i*90,0]) scale([0.7,1,1]) ring(); } module nested() { } module recursive() { ring_r(0,19,18); } //iterative(); recursive(); -- View this message in context: http://forum.openscad.org/Why-are-recursive-definitions-slow-tp12427.html Sent from the OpenSCAD mailing list archive at Nabble.com.