Trying out Cadhub.xyz

Trying out Cadhub.xyz

cadhub.xyz/u/TLC123/unionRoundMask-scad

ComplementryRGBColor

ComplementryRGBColor calculates the opposite point of the 
color wheel to resolve the complementary color



for(i=[0:360/20:180]){
c=rands(0,1,3,i);
rotate(i,[0,.1,1])
 {
  color(c)render()translate([5,5])square(10);
  color(complementryRGBColor(c))render()translate([13,13])square(10);
}
echo(c,complementryRGBColor(c));
}
function complementryRGBColor(c) =
let (r = c[0], g = c[1], b = c[2])
(max(r, g, b) == min(r, g, b)) ? 
  [1 - r, 1 - g, 1 - b] : 
let (mx = max(r, g, b),
     mn = min(r, g, b), 
     h = (mx + mn) / 2, 
     s = (mx + mn) / 2, 
     l = (mx + mn) / 2, 
     d = mx - mn)
let (s = l > 0.5 ? d / (2 - mx - mn) : d / (mx + mn), 
     h = mx == r ? (g - b) / d + (g < b ? 6 : 0) : 
     mx == g ? (b - r) / d + 2 :
    /*mx== b?*/     (r - g) / d + 4)
let (h = round((h * 60) + 180) % 360)
let (h = h / 360)
let (hue2rgb = function(p, q, t) 
     let (t = t - floor(t))
     (t < 1 / 6) ? p + (q - p) * 6 * t : 
     (t < 1 / 2) ? q : 
     (t < 2 / 3) ? p + (q - p) * (2 / 3 - t) * 6 : 
     p)
let (q = l < 0.5 ?  l * (1 + s) :  l + s - l * s)
let (p = 2 * l - q)
let (r = hue2rgb(p, q, h + 1 / 3))
let (g = hue2rgb(p, q, h))
let (b = hue2rgb(p, q, h - 1 / 3))[r, g, b];
 

OpenSCAD unionRound() Module

One of the most common request is boolean operations with fillet/chamfer/rounding/radius/smoothing . Most option so far has been unsatisfactory or glacially slow.

Updated version at Github
  

Enabled by fast convex + convex minkowski sum. Thanks whoever implemented that.

Unions of simple operands has a general FAST solution in all cases where the joint area is convex

For non convex operands, a simple masking system enable us to isolate out only local convex areas to process.

Masks are in practice a common volume that both operands are first intersected by.

Though not a complete solution a good part of common cases can be filleted. (se limitations.)

With an exploit of fast convex + convex minkowski and the Theorem: Given any collection of convex sets, their intersection is itself a convex set.
The following became possible:

  

[OpenSCAD issue 844 - fillet/chamfer union operation ]
[OpenSCAD issue 3447 - Feature suggestion: Fillet and chamfer]

   ////////////////////////////////////////////////////////
    /*
    unionRound() 1.0 Module by Torleif Ceder - TLC123 late summer 2021
     Pretty fast Union with radius, But limited to a subset of cases
    Usage 
     unionRound( radius , detail  )
        {
         YourObject1();
         YourObject2(); 
        } 
      unionRoundMask (r, detail , epsilon ,showMask )
        {
         YourObject1();
         YourObject2(); 
         YourMask();
         YourMask();   
         
         // ...
         // ...
         // ...
         
        } 
    limitations: 
     0. Only really fast when boolean operands are convex, 
            Minkowski is fast in that case. 
     1. Boolean operands may be concave but can only touch 
            in a single convex area
     2. Radius is of elliptic type and is only approximate r
            were operand intersect at perpendicular angle. 
    */
    //////////////////////////////////////////////////////// 
    // Demo code
    demo= false;
    if (demo)  
     unionRoundMask( r=1.5 , detail= 5 , q=70
    , includeOperands = true) {
     cube([10,10,2],true);
     rotate([20,-10,0])cylinder(5,1,1,$fn=12);   
     translate([0,0,1.5])cube([1.5,10,3],center=true); //mask
      rotate(90)
     translate([0,0,1.5])cube([3,10,3],center=true); //mask
    }
    
    // end of demo code
    //
    module unionRoundMask(r=1, detail = 5,q=70, epsilon = 1e-6
    , showMask = true, includeOperands = true) {
    //automask if none
    if($children <=2){
        unionRoundMask(r,detail,q,epsilon,showMask, includeOperands)
        {
            children(0);
            children(1);
            clad(r,q) intersection(){
                    children(0);
                    children(1);
                }
            }
            }
        else {
        union() {
          if(includeOperands){ 
                children(0);
                children(1);
               }
            if (showMask && $children > 2) %
                for (i = [2: max(2, $children - 1)]) children(i);

            if ($children > 2)
                for (i = [2: max(2, $children - 1)]) {
                    intersection() {
                        children(i);

                        unionRound(r, detail,q, epsilon
    ,includeOperands) {
                            intersection() {
                                children(0);
                                children(i); // mask
                            }
                            intersection() {
                                children(1);
                                children(i); // mask
                            }
                        }
                    }
                }
            }
         }
    }
    
    
    module unionRound(r=1, detail = 5,q=70,  epsilon = 1e-6
    , includeOperands=true) {
       if(includeOperands){ 
        children(0);
        children(1);
       }
        step = 90 / detail;
      union()for (i = [0:  detail-1]) {
            {
                x = r - sin(i * step ) * r;
                y = r - cos(i * step ) * r;
                xi = r - sin((i * step + step)  ) * r;
                yi = r - cos((i * step + step)  ) * r;
                color(rands(0, 1, 3, i))
                hull() {
                    intersection() {
                        // shell(epsilon) 
                        clad(x,q) children(0);
                        // shell(epsilon) 
                        clad(y,q) children(1);
                    }
                    intersection() {
                        // shell(epsilon) 
                        clad(xi,q) children(0);
                        // shell(epsilon) 
                        clad(yi,q) children(1);
                    }
                }
            }
        }
    }
    
    // prototype module slow maybe on concave feature
    module intersectionRound(r, q=70,  epsilon = 1e-6

,showOperands = true) {

        %if (showOperands){children(0);
        children(1);}
 
                    clad(r,q) inset(r,q)
                     hull()intersection() {
                           children(0);
                           children(1);
                    }
 
    }
    
    // unionRound helper expand by r
    module clad(r,q=70) {
        minkowski() {
            children();
            //        icosphere(r,2);
             isosphere(r,q); 
        }
    }
    // unionRound helper
    module shell(r,q=70) {
        difference() {
            clad(r,q) children();
            children();
        }
    }
    
    // inset 3d  "negative offset", optimally on convex hull
    // else jagged inner corners by q quality factor 
    module inset(r,q=20){
    a= generatepoints(q)*r;
    //#children();
    intersection_for(t=a){
      translate(t ) children();
    }
    }
    
    
    /*    
    // The following is a sphere with some equidistant properties.
    // Not strictly necessary

    Kogan, Jonathan (2017) 
    "A New Computationally Efficient Method for 
    Spacing n Points on a Sphere," 
    Rose-Hulman Undergraduate Mathematics Journal: 
    Vol. 18 : Iss. 2 , Article 5.
    Available at: 
    https://scholar.rose-hulman.edu/rhumj/vol18/iss2/5 */
    
    function sphericalcoordinate(x,y)=[cos(x)*cos(y),sin(x)*cos(y),sin(y)];
    function NX(n=70,x)= 
    let(toDeg=57.2958,PI=acos(-1)/toDeg,
    start=(-1.+1./(n-1.)),increment=(2.-2./(n-1.))/(n-1.) )
    [ for (j= [0:n-1])let (s=start+j*increment )
    sphericalcoordinate(s*x*toDeg,PI/2.*sign(s)*(1.-sqrt(1.-abs(s)))*toDeg)];
    function generatepoints(n=70)= NX(n,0.1+1.2*n);
    module isosphere(r,q=70){
    a= generatepoints(q);
    scale(r)hull()polyhedron(a,[[for(i=[0:len(a)-1])i]]);
    }

on Youtube
on GitHub
on Thingiverse
on OpenSCAD Snippet Pad
on r /OpenSCAD

My OpenSCAD Feature wish list.

Language:
- Reference image import - based on surface()  just zero height and a texture.
        OpenCSG very much support this out of the box.

- Native Minkowski over 1D and 2D primitives.

- Native function import .scad file as pre render in [ points , faces ].
        this closes the loop a bit. At least save current mesh result as a 
         polyhedron([ points , faces ])   .dot scad file.

- Auto crop shape when:
ERROR: all points for rotate_extrude() must have the same X coordinate sign

- importMetrics catching information about imported files  similar to textmetrics()

Gui:

- Save/display depth map and normal map from render pipeline to png.
- Animation play- pause
- Ambient SSAO 

- Auto indent selection and general code beautifier
-  Save current mesh result as a 
         polyhedron([ points , faces ])   .dot scad file.


T.B.C.

Elon Musk on The Five Steps

The Five steps.

Elon Musk, in an interview with Tim Dodd, outlined five essential steps of manufacture design.
The two met at starbase late summer of 2021 for a tour. At the meeting Elon stressed that designing a prototype is very simple when compared to the complexity of designing volume production. Something that Elon Musk earlier has called "the machine that makes the machine". The full interview series are available on Tim Dodd's Youtube channel - The Everyday Astronaut,

The five steps were as mentioned:

1. Make requermens less dumb.
2. Try really hard to delete the part or delete the process.
3  Simplify or optimize.
4. Accelerate cycle time.
5. Automate.

notes:

step 1
    / your requirements are likely dumb.
      Especially if they come from a really smart person.     

step 2
    / Put persons name on requirement not department.
    / “If you’re not adding things back in 10% of the time, 
       you’re clearly not deleting enough from your design.”

step 3
    / First begin when 1. and 2. is exhausted

step 4
    / "cycle" Assumed to be iterations of innovations in contrast to 5.

Mastering OpenSCAD within 10 projects by Jochen Kerdels:

Mastering OpenSCAD within 10 projects by Jochen Kerdels 
 


https://www.amazon.com/Mastering-OpenSCAD-within-10-projects/dp/3753458589

Autogenous pressurize through mutual in-tank combustion

#WhyDontTheyJust #WDTJ #OLF  Wouldn't tanks pressurize autogenous if you injected a small amount of LOX into fuel tank and vise versa, over catalyst bed, basically reacting it in the ullage of the tank.

Dielectric High Temp Seal

Dielectric High Temp Seal . 
A non conduction high temperature seal can be achieved by separating the two functions of elasticity and isolation. Such that the insulation flange (Ceramic) only see compression.


  


tag: Donald Sadoway,
Ambri , battery antimony, salt, seal, insulator, dielectric