I am trying to make a shape/model which is comprised of a few other shapes
added and subtracted from each other. When I did this using Fusion 360, I
used a transparency setting which allowed me to visually confirm that I was
achieving my aim. Unfortunately, the alpha setting for the color command
doesn't seem to have the same effect - it doesn't allow me to see the inside
of my shape. Is there some way I can get to see the inside of my shape from
the outside, as I can in other software (e.g. Google Sketchup, Fusion 360
and 123Design)?

http://forum.openscad.org/file/t2755/openscad.png
http://forum.openscad.org/file/t2755/fusion.png

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Sent from: http://forum.openscad.org/

Not within an object. you have to cut them open, e.g.

module cut(s=10000) {
difference() {
children();
translate([-s/2,0,0])
cube(s);
}
}

cut()
difference() {
cylinder(20,20,20,center=true);
cylinder(16,16,16,center=true);
}

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In OpenSCAD the order of objects plays a role, whether a look inside into a
transparent object (alpha<1) is presented or not. Thus this object must be
evaluated last.

See this codes:

color("yellow",.5)cube (20, center =true);  // transparent only for objects
already displayed
color("green",1)  cube (10, center =true);  // not visible

vs.

color("green",1)  cube (10, center =true);  // visible
color("yellow",.5)cube (20, center =true);  // transparent only objects
already displayed

the problem is, you can't change the order in cases like the following

difference()
{
color("yellow",.5)cube (20, center =true);
color("green",1)  cube (10, center =true);
}

my trick to look through all coats in such a case is the temporal
redefinition of difference() into a union having the right order.

cube (5, center =true);
difference()
{
cube (20, center =true);
cube (10, center =true);
}

module difference()
color("green",.3)
{
children([1:$children-1]);
children(0);
}

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