Volume of mesh

Calculates the volume of a point-face triangel mesh. 
points=[[0,0,0], ... ]
faces=[[0,1,2],[0,2,3],[4,6,5],[4,7,6],
    [0,4,5],[1,0,5],[1,5,6],[2,1,6],
    [2,6,7],[2,7,3],[3,7,4],[3,0,4]]    
function    meshVolume(points,faces)=
   let(
 
    sum=[for(faces)-1]*[for(f=faces)
SignedVolumeOfTriangle(points[f[0]],points[f[1]],points[f[2]])])
    sum
    
    
    
    
    ;
    
    
   function SignedVolumeOfTriangle(  p1,   p2,   p3) =
    let(
     v321 = p3.x*p2.y*p1.z,
     v231 = p2.x*p3.y*p1.z,
     v312 = p3.x*p1.y*p2.z,
     v132 = p1.x*p3.y*p2.z,
     v213 = p2.x*p1.y*p3.z,
     v123 = p1.x*p2.y*p3.z
)     (1.0/6.0)*(-v321 + v231 + v312 - v132 - v213 + v123);
 

Marching Cubes for OpenSCAD function literals

Marching Cubes for OpenSCAD function literals   
Usage:   sdMarchingCubes( sdScene = f ( [ x , y , z ] ) , sub = subdivisions )

// MarchingCubes for function literals v0.1 - Torleif Ceder 2020
// With function literals of bounded closed isosufaces 
// in the form f([x,y,z])
// Signed distans function can be output as polyhedron.
// Quality and problens is as expected with MarchingCubes
////////////// DEMO ////////////////////////////////////////////////////////////
sdScene   = function(p) min(
  max(abs(p.x)-6.5,abs(p.y+3)-4.5,abs(p.z*.7-p.x*.7)-0.5)  ,
  max(abs(p.x)-6.5,abs(p.y-3)-4.5,abs(p.z*.7+p.x*.7)-0.5)  ,
  norm(p )-5.5 ); // function literal of our Signed distance function
  // learn more at https://iquilezles.org/www/articles/distfunctions/distfunctions.htm

sdDemo= true;
if(sdDemo) sdMarchingCubes(sdScene,sub=5);

/////////////////////////////////////////////////////////////////////////////////////
//sdMC is a Octree subdivision MarchingCubes with direct gemoetry output
 module sdMarchingCubes(sdScene, cell=[],sub){
     assert(!is_undef(sub)&&!is_undef(sdScene),
     " sdMarchingCubes() Usage: sdMarchingCubes( sdScene = f([ x , y , z ]) , sub = subdivisions ) ")
if (cell==[]) sdMarchingCubes(sdScene,autoBound(sdScene,cubic=true,pad=0.5 ),sub); else{
    O = cell[0]; S = cell[1];  C = (O + S) / 2; D = S - O;
    maxD = max( abs (D.x),abs (D.y),abs (D.z));
     if (abs(sdScene(C))<=maxD )//ignore completly empty or full cells
    {        p=vertFromCell  (cell) ;
             evals=[for(p=p)eval(p,sdScene)]; 
             case=bitMaskToValue(evals);
          if (sub>0){  // subdivide cell into eight  smaller if subdivisions left      
                    pxxx=[O+[0,0,0],O+[D.x,0,0],O+[0,D.y,0],O+[0,D.y,D.z],
                    O+[0,0,D.z],O+[D.x,D.y,0],O+[D.x,0,D.z],O+[D.x,D.y,D.z]];
                    for(i=[0:7]){sdMarchingCubes(sdScene,([C,pxxx[i]]),sub-1 );  }    } 
         
        else         { // Make polyhedron of this cell
            faces=(CASES()[ (case)]); // Use MC 256 table to find conectivity
            edgepoints=[for(e=EDGES())  // intersecion points along edges
                lerp(p[e[0]],p[e[1]], findZero(evals[e[0]],evals[e[1]]) )];
              polyhedron(edgepoints,faces); } } } } // Showtime

/////////////////////////////////////////////////////////////////////////////////////
// tiny utils fuctions
function vertFromCell(cell)= [for(c=VERTICES())[cell[c.x].x,cell[c.y].y,cell[c.z].z ]]; 
function findZero(e1,e2)=sign(e1)==sign(e2)||e1+e2==0?0.5:  (abs(e1)/(abs(e1)+abs(e2)) );
function lerp(start,end,bias) = (end * bias + start * (1 - bias));
function un(v) = v / max(norm(v), 0.000001) * 1; // div by zero safe unit normal
function clamp(a,b=0,c=1) =  min(max(a,min(b,c)),max(b,c));
/////////////////////////////////////////////////////////////////////////////////////
function eval(p,sdScene)=sdScene(p);// For legacy 
//////////////////////////////////////////////////////////////////////////////////////
function evalnorm(q,sdScene) =
let (tiny = -1e16, e = eval(q,sdScene))[
eval([q.x + tiny,q.y,q.z],sdScene) - eval([q.x - tiny,q.y,q.z],sdScene),
eval([q.x,q.y + tiny,q.z],sdScene) - eval([q.x,q.y - tiny,q.z],sdScene),
eval([q.x,q.y,q.z + tiny],sdScene) - eval([q.x,q.y,q.z - tiny],sdScene),    e];
//////////////////////////////////////////////////////////////////////////////////////
// Takes a vector. Any number >0 is 1 rest 0. use binary to build a number 
function bitMaskToValue(v=[0])= is_undef(v[0])?0:
 [for(j=v)1]* [for (i=[0:max(0,len(v)-1)]) max(0,sign(v[i]))*pow(2,i)] ;
//////////////////////////////////////////////////////////////////////////////////////
// arrange bundary box from sloppy to proper orientation of minor corner and major corner
function bflip(a,b) = is_undef(b)&&len(a)==2?bflip(a[0],a[1]):[ [min(a.x,b.x),min(a.y,b.y),min(a.z,b.z)], [max(a.x,b.x),max(a.y,b.y),max(a.z,b.z)] ];
 //////////////////////////////////////////////////////////////////////////////////////
function autoBound(sdScene,cubic = (false),pad = 1) =    let (
    up = findBound([0,0,1],sdScene),    down = -findBound([0,0,-1],sdScene),
    north = findBound([0,1,0],sdScene),    south = -findBound([ 0,-1,0],sdScene),
    west = findBound([1,0,0],sdScene),    east = -findBound([- 1,0,0],sdScene),
    esd = min(east,south,down),wnu = max(west,north,up)    ) 
cubic == true ?
let(scenecenter=[(east+west)/2,(south+north)/2,(up+down)/2],
    scenemax=max(abs(east-west),abs(south-north),abs(up+down))/2,
    d = [scenemax,scenemax,scenemax]   )
    [scenecenter - (d * (1+pad)),scenecenter + d * (1+pad)]  :
    let (d = [west,north,up ] - [east,south,down])
    [[east,south,down ] - d * pad,[west,north,up] + d * pad];
//////////////////////////////////////////////////////////////////////////////////////
function findBound(vec,sdScene) =
let (VeryFar = 10e6,  p1 = vec * VeryFar, p2 = p1 + un(vec  ),
e1 = abs(eval(p1,sdScene)),  e2 = abs(eval(p2,sdScene)),
scale = abs(e2 - e1),// Account for non unit_for_unit field.
corrected = (e1 / scale), distance = VeryFar - e1/scale //distance= VeryFar-corrected
)/*[p1,p2,e1,e2,scale,corrected,distance ]*/ distance ;
//////////////////////////////////////////////////////////////////////////////////////
////// MC Tables by BorisTheBrav /////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////////////
function  VERTICES ()= [
    [0,0,0],    [1,0,0],
    [1,1,0],    [0,1,0],
    [0,0,1],    [1,0,1],
    [1,1,1],    [0,1,1],    ];
//# BorisTheBrave convention for the edges
function EDGES() = [
    [0,1],    [1,2],    [2,3],
    [3,0],    [4,5],    [5,6],
    [6,7],    [7,4],    [0,4],
    [1,5],    [2,6],    [3,7]  ];
//BorisTheBrave # Table driven approach to the 256 combinations. Pro-tip,don't write this by hand,copy mine!
//BorisTheBrave# See marching_cubes_gen.py for how I generated these.
//BorisTheBrave# Each index is the bitwise representation of what is solid.
//BorisTheBrave# Each value is a list of triples indicating what edges are used for that triangle
//BorisTheBrave# (Recall each edge of the cell may become a vertex in the output boundary)
function CASES() = [[],[[8,0,3]],[[1,0,9]],[[8,1,3],[8,9,1]],[[10,2,1]],[[8,0,3],[1,10,2]],[[9,2,0],[9,10,2]],[[3,8,2],[2,8,10],[10,8,9]],[[3,2,11]],[[0,2,8],[2,11,8]],[[1,0,9],[2,11,3]],[[2,9,1],[11,9,2],[8,9,11]],[[3,10,11],[3,1,10]],[[1,10,0],[0,10,8],[8,10,11]],[[0,11,3],[9,11,0],[10,11,9]],[[8,9,11],[11,9,10]],[[7,4,8]],[[3,7,0],[7,4,0]],[[7,4,8],[9,1,0]],[[9,1,4],[4,1,7],[7,1,3]],[[7,4,8],[2,1,10]],[[4,3,7],[4,0,3],[2,1,10]],[[2,0,10],[0,9,10],[7,4,8]],[[9,10,4],[4,10,3],[3,10,2],[4,3,7]],[[4,8,7],[3,2,11]],[[7,4,11],[11,4,2],[2,4,0]],[[1,0,9],[2,11,3],[8,7,4]],[[2,11,1],[1,11,9],[9,11,7],[9,7,4]],[[10,11,1],[11,3,1],[4,8,7]],[[4,0,7],[7,0,10],[0,1,10],[7,10,11]],[[7,4,8],[0,11,3],[9,11,0],[10,11,9]],[[4,11,7],[9,11,4],[10,11,9]],[[9,4,5]],[[9,4,5],[0,3,8]],[[0,5,1],[0,4,5]],[[4,3,8],[5,3,4],[1,3,5]],[[5,9,4],[10,2,1]],[[8,0,3],[1,10,2],[4,5,9]],[[10,4,5],[2,4,10],[0,4,2]],[[3,10,2],[8,10,3],[5,10,8],[4,5,8]],[[9,4,5],[11,3,2]],[[11,0,2],[11,8,0],[9,4,5]],[[5,1,4],[1,0,4],[11,3,2]],[[5,1,4],[4,1,11],[1,2,11],[4,11,8]],[[3,10,11],[3,1,10],[5,9,4]],[[9,4,5],[1,10,0],[0,10,8],[8,10,11]],[[5,0,4],[11,0,5],[11,3,0],[10,11,5]],[[5,10,4],[4,10,8],[8,10,11]],[[9,7,5],[9,8,7]],[[0,5,9],[3,5,0],[7,5,3]],[[8,7,0],[0,7,1],[1,7,5]],[[7,5,3],[3,5,1]],[[7,5,8],[5,9,8],[2,1,10]],[[10,2,1],[0,5,9],[3,5,0],[7,5,3]],[[8,2,0],[5,2,8],[10,2,5],[7,5,8]],[[2,3,10],[10,3,5],[5,3,7]],[[9,7,5],[9,8,7],[11,3,2]],[[0,2,9],[9,2,7],[7,2,11],[9,7,5]],
[[3,2,11],[8,7,0],[0,7,1],[1,7,5]],[[11,1,2],[7,1,11],[5,1,7]],[[3,1,11],[11,1,10],[8,7,9],[9,7,5]],[[11,7,0],[7,5,0],[5,9,0],[10,11,0],[1,10,0]],[[0,5,10],[0,7,5],[0,8,7],[0,10,11],[0,11,3]],[[10,11,5],[11,7,5]],[[5,6,10]],[[8,0,3],[10,5,6]],[[0,9,1],[5,6,10]],[[8,1,3],[8,9,1],[10,5,6]],[[1,6,2],[1,5,6]],[[6,2,5],[2,1,5],[8,0,3]],[[5,6,9],[9,6,0],[0,6,2]],[[5,8,9],[2,8,5],[3,8,2],[6,2,5]],[[3,2,11],[10,5,6]],[[0,2,8],[2,11,8],[5,6,10]],[[3,2,11],[0,9,1],[10,5,6]],[[5,6,10],[2,9,1],[11,9,2],[8,9,11]],[[11,3,6],[6,3,5],[5,3,1]],[[11,8,6],[6,8,1],[1,8,0],[6,1,5]],[[5,0,9],[6,0,5],[3,0,6],[11,3,6]],[[6,9,5],[11,9,6],[8,9,11]],[[7,4,8],[6,10,5]],[[3,7,0],[7,4,0],[10,5,6]],[[7,4,8],[6,10,5],[9,1,0]],[[5,6,10],[9,1,4],[4,1,7],[7,1,3]],[[1,6,2],[1,5,6],[7,4,8]],[[6,1,5],[2,1,6],[0,7,4],[3,7,0]],[[4,8,7],[5,6,9],[9,6,0],[0,6,2]],[[2,3,9],[3,7,9],[7,4,9],[6,2,9],[5,6,9]],[[2,11,3],[7,4,8],[10,5,6]],[[6,10,5],[7,4,11],[11,4,2],[2,4,0]],[[1,0,9],[8,7,4],[3,2,11],[5,6,10]],[[1,2,9],[9,2,11],[9,11,4],[4,11,7],[5,6,10]],
[[7,4,8],[11,3,6],[6,3,5],[5,3,1]],[[11,0,1],[11,4,0],[11,7,4],[11,1,5],[11,5,6]],[[6,9,5],[0,9,6],[11,0,6],[3,0,11],[4,8,7]],[[5,6,9],[9,6,11],[9,11,7],[9,7,4]],[[4,10,9],[4,6,10]],[[10,4,6],[10,9,4],[8,0,3]],[[1,0,10],[10,0,6],[6,0,4]],[[8,1,3],[6,1,8],[6,10,1],[4,6,8]],[[9,2,1],[4,2,9],[6,2,4]],[[3,8,0],[9,2,1],[4,2,9],[6,2,4]],[[0,4,2],[2,4,6]],[[8,2,3],[4,2,8],[6,2,4]],[[4,10,9],[4,6,10],[2,11,3]],[[11,8,2],[2,8,0],[6,10,4],[4,10,9]],[[2,11,3],[1,0,10],[10,0,6],[6,0,4]],[[8,4,1],[4,6,1],[6,10,1],[11,8,1],[2,11,1]],[[3,1,11],[11,1,4],[1,9,4],[11,4,6]],[[6,11,1],[11,8,1],[8,0,1],[4,6,1],[9,4,1]],[[3,0,11],[11,0,6],[6,0,4]],[[4,11,8],[4,6,11]],[[6,8,7],[10,8,6],[9,8,10]],[[3,7,0],[0,7,10],[7,6,10],[0,10,9]],[[1,6,10],[0,6,1],[7,6,0],[8,7,0]],[[10,1,6],[6,1,7],[7,1,3]],[[9,8,1],[1,8,6],[6,8,7],[1,6,2]],[[9,7,6],[9,3,7],[9,0,3],[9,6,2],[9,2,1]],[[7,6,8],[8,6,0],[0,6,2]],[[3,6,2],[3,7,6]],[[3,2,11],[6,8,7],[10,8,6],[9,8,10]],[[7,9,0],[7,10,9],[7,6,10],[7,0,2],[7,2,11]],[[0,10,1],[6,10,0],[8,6,0],[7,6,8],[2,11,3]],[[1,6,10],[7,6,1],[11,7,1],[2,11,1]],[[1,9,6],[9,8,6],[8,7,6],[3,1,6],[11,3,6]],
[[9,0,1],[11,7,6]],[[0,11,3],[6,11,0],[7,6,0],[8,7,0]],[[7,6,11]],[[11,6,7]],[[3,8,0],[11,6,7]],[[1,0,9],[6,7,11]],[[1,3,9],[3,8,9],[6,7,11]],[[10,2,1],[6,7,11]],[[10,2,1],[3,8,0],[6,7,11]],[[9,2,0],[9,10,2],[11,6,7]],[[11,6,7],[3,8,2],[2,8,10],[10,8,9]],[[2,6,3],[6,7,3]],[[8,6,7],[0,6,8],[2,6,0]],[[7,2,6],[7,3,2],[1,0,9]],[[8,9,7],[7,9,2],[2,9,1],[7,2,6]],[[6,1,10],[7,1,6],[3,1,7]],[[8,0,7],[7,0,6],[6,0,1],[6,1,10]],[[7,3,6],[6,3,9],[3,0,9],[6,9,10]],[[7,8,6],[6,8,10],[10,8,9]],[[8,11,4],[11,6,4]],[[11,0,3],[6,0,11],[4,0,6]],[[6,4,11],[4,8,11],[1,0,9]],[[1,3,9],[9,3,6],[3,11,6],[9,6,4]],[[8,11,4],[11,6,4],[1,10,2]],[[1,10,2],[11,0,3],[6,0,11],[4,0,6]],[[2,9,10],[0,9,2],[4,11,6],[8,11,4]],[[3,4,9],[3,6,4],[3,11,6],[3,9,10],[3,10,2]],[[3,2,8],[8,2,4],[4,2,6]],[[2,4,0],[6,4,2]],[[0,9,1],[3,2,8],[8,2,4],[4,2,6]],[[1,2,9],[9,2,4],[4,2,6]],[[10,3,1],[4,3,10],[4,8,3],[6,4,10]],[[10,0,1],[6,0,10],[4,0,6]],[[3,10,6],[3,9,10],[3,0,9],[3,6,4],[3,4,8]],[[9,10,4],[10,6,4]],[[9,4,5],[7,11,6]],[[9,4,5],[7,11,6],[0,3,8]],[[0,5,1],[0,4,5],[6,7,11]],[[11,6,7],[4,3,8],[5,3,4],[1,3,5]],[[1,10,2],[9,4,5],[6,7,11]],
[[8,0,3],[4,5,9],[10,2,1],[11,6,7]],[[7,11,6],[10,4,5],[2,4,10],[0,4,2]],[[8,2,3],[10,2,8],[4,10,8],[5,10,4],[11,6,7]],[[2,6,3],[6,7,3],[9,4,5]],[[5,9,4],[8,6,7],[0,6,8],[2,6,0]],[[7,3,6],[6,3,2],[4,5,0],[0,5,1]],[[8,1,2],[8,5,1],[8,4,5],[8,2,6],[8,6,7]],[[9,4,5],[6,1,10],[7,1,6],[3,1,7]],[[7,8,6],[6,8,0],[6,0,10],[10,0,1],[5,9,4]],[[3,0,10],[0,4,10],[4,5,10],[7,3,10],[6,7,10]],[[8,6,7],[10,6,8],[5,10,8],[4,5,8]],[[5,9,6],[6,9,11],[11,9,8]],[[11,6,3],[3,6,0],[0,6,5],[0,5,9]],[[8,11,0],[0,11,5],[5,11,6],[0,5,1]],[[6,3,11],[5,3,6],[1,3,5]],[[10,2,1],[5,9,6],[6,9,11],[11,9,8]],[[3,11,0],[0,11,6],[0,6,9],[9,6,5],[1,10,2]],[[0,8,5],[8,11,5],[11,6,5],[2,0,5],[10,2,5]],[[11,6,3],[3,6,5],[3,5,10],[3,10,2]],[[3,9,8],[6,9,3],[5,9,6],[2,6,3]],[[9,6,5],[0,6,9],[2,6,0]],[[6,5,8],[5,1,8],[1,0,8],[2,6,8],[3,2,8]],[[2,6,1],[6,5,1]],[[6,8,3],[6,9,8],[6,5,9],[6,3,1],[6,1,10]],[[1,10,0],[0,10,6],[0,6,5],[0,5,9]],[[3,0,8],[6,5,10]],[[10,6,5]],[[5,11,10],[5,7,11]],[[5,11,10],[5,7,11],[3,8,0]],[[11,10,7],[10,5,7],[0,9,1]],[[5,7,10],[10,7,11],[9,1,8],[8,1,3]],[[2,1,11],[11,1,7],[7,1,5]],[[3,8,0],[2,1,11],[11,1,7],[7,1,5]],[[2,0,11],[11,0,5],[5,0,9],[11,5,7]],[[2,9,5],[2,8,9],[2,3,8],[2,5,7],[2,7,11]],[[10,3,2],[5,3,10],[7,3,5]],[[10,0,2],[7,0,10],[8,0,7],[5,7,10]],[[0,9,1],[10,3,2],[5,3,10],[7,3,5]],[[7,8,2],[8,9,2],[9,1,2],[5,7,2],[10,5,2]],[[3,1,7],[7,1,5]],[[0,7,8],[1,7,0],[5,7,1]],[[9,5,0],[0,5,3],[3,5,7]],[[5,7,9],[7,8,9]],[[4,10,5],[8,10,4],[11,10,8]],[[3,4,0],[10,4,3],[10,5,4],[11,10,3]],[[1,0,9],[4,10,5],[8,10,4],[11,10,8]],
[[4,3,11],[4,1,3],[4,9,1],[4,11,10],[4,10,5]],[[1,5,2],[2,5,8],[5,4,8],[2,8,11]],[[5,4,11],[4,0,11],[0,3,11],[1,5,11],[2,1,11]],[[5,11,2],[5,8,11],[5,4,8],[5,2,0],[5,0,9]],[[5,4,9],[2,3,11]],[[3,4,8],[2,4,3],[5,4,2],[10,5,2]],[[5,4,10],[10,4,2],[2,4,0]],[[2,8,3],[4,8,2],[10,4,2],[5,4,10],[0,9,1]],[[4,10,5],[2,10,4],[1,2,4],[9,1,4]],[[8,3,4],[4,3,5],[5,3,1]],[[1,5,0],[5,4,0]],[[5,0,9],[3,0,5],[8,3,5],[4,8,5]],[[5,4,9]],[[7,11,4],[4,11,9],[9,11,10]],[[8,0,3],[7,11,4],[4,11,9],[9,11,10]],[[0,4,1],[1,4,11],[4,7,11],[1,11,10]],[[10,1,4],[1,3,4],[3,8,4],[11,10,4],[7,11,4]],[[9,4,1],[1,4,2],[2,4,7],[2,7,11]],[[1,9,2],[2,9,4],[2,4,11],[11,4,7],[3,8,0]],[[11,4,7],[2,4,11],[0,4,2]],[[7,11,4],[4,11,2],[4,2,3],[4,3,8]],[[10,9,2],[2,9,7],[7,9,4],[2,7,3]],[[2,10,7],[10,9,7],[9,4,7],[0,2,7],[8,0,7]],[[10,4,7],[10,0,4],[10,1,0],[10,7,3],[10,3,2]],[[8,4,7],[10,1,2]],[[4,1,9],[7,1,4],[3,1,7]],[[8,0,7],[7,0,1],[7,1,9],[7,9,4]],[[0,7,3],[0,4,7]],[[8,4,7]],[[9,8,10],[10,8,11]],[[3,11,0],[0,11,9],[9,11,10]],[[0,10,1],[8,10,0],[11,10,8]],[[11,10,3],[10,1,3]],[[1,9,2],[2,9,11],[11,9,8]],[[9,2,1],[11,2,9],[3,11,9],[0,3,9]],[[8,2,0],[8,11,2]],[[11,2,3]],[[2,8,3],[10,8,2],[9,8,10]],[[0,2,9],[2,10,9]],[[3,2,8],[8,2,10],[8,10,1],[8,1,0]],[[1,2,10]],[[3,1,8],[1,9,8]],[[9,0,1]],[[3,0,8]],[]];

Six Panel Boca Chica Live

https://tlc123.github.io/BocaChica.html

Self Balancing Compact Loader

Skid steer compact loader can reduce tire wear and slip with a computer controlled self balancing system. Low pressure tires ensure excellent grip in loose soil.

Solar Trail Tail

Overlanding vehicles could be powered by a series of connected trailers. Each carrying a solar panel contributing to power the main tractor vehicle.
When not in us,e the trailers can be collapsed and stacked on top.

 























Hey look What i found:

Social Unmasking Personal Protection

Unmask: Socially enhanced PPE design

transparent area in front of mouth to unmask mouth mimicry.

Extended filter area on rear part of cheeks to makeup for lost area.

Is legs on a EVA suit really worth it?

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SpaceX Spiral welded tube

Spiral weld stainless 30X into a tube that can be continuously
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{


    //
    for (i = [-1: 0.01: 3])

        color("gray") hull() {
            translate([jsin(10 * i * 360) * 0.1, 0, 0])
            translate([i * 2, min(i, 0) * -12, 0]) rotate([max(i, 0) * 360, 0, 0]) 

translate([0, 0, 2]) cube([2 - 0.1, 0.01, 0.001], center = true);
            j = i + 0.01;
            translate([jsin(10 * j * 360) * 0.1, 0, 0])
            translate([j * 2, min(j, 0) * -12, 0]) rotate([max(j, 0) * 360, 0, 0]) 

translate([0, 0, 2]) cube([2 - .1, 0.01, 0.001], center = true);
        }

    // uncut stainless
    color("gray") translate([-0.17, 1, 0] * 0.22)
    translate([0, 0, 2])
    linear_extrude(0.002)
    polygon([
        [-3, 12],
        [-1, 12],
        [0, 6],
        [-2, 6]
    ]);




    // final rocket trunk
    translate([4, 0, 0]) color([0.6, 0.6, 0.6]) rotate([0, 90, 0])

 linear_extrude(13) difference() {
        $fn = 120;
        circle(2 - 0.001);
        circle(2 - 0.002);
    }
    $fn = 120;

    // laser cutter profile edges
    color([0.4, 0.5, 0.7]) translate([-1.8, 12] * 0.5) translate([0, 0, 2]) 

cube([2.4, 0.5, 1], center = true);

    // coil
    color([0.6, 0.6, 0.6]) translate([-2, 12] * 1.025) translate([0, 0, 1]) 

rotate([0, 0, 7]) rotate([0, 90, 0]) cylinder(2, 1, 1, center = true);


    // xray and heat treat
    color("red") rotate([30, 0, 0]) translate([1, 0, 2]) cube([.5, 0.25, 1], center = true);
    color("orange") rotate([50, 0, 0]) translate([1, 0, 2]) cube([.5, 0.25, 1], center = true);
    color("gold") rotate([60, 0, 0]) translate([1, 0, 2]) cube([.5, 0.25, 1], center = true);
    color("blue") rotate([90, 0, 0]) translate([1, 0, 2]) cube([.5, 0.25, 1], center = true);


    //welder
    color("yellow") rotate([1, 0, 0]) translate([1, 0, 2]) cube([.125, 0.125, 1.5], center = true);
    color([1, .8, .3]) rotate([1, 0, 0]) translate([1, 0, 2]) cube([.4, 0.4, .25], center = true);


}

function jsin(s) =
max(clamp(sin(s + 60) * 3, -0.5, 0.5), clamp(sin(s) * 3, -0.5, 0.5));


function clamp(a, b, c) = min(max(a, min(b, c)), max(b, c));