Hello,

I have the following code which appears fine in F6 render (and makes a
manifold mesh afaics) but does not appear in the F5 preview.

I tried adding convexity=10 to each union/difference/hull which often
works for me, but made no difference here.

I realise I am abusing hull() to avoid making proper polyhedrons out
of laziness, but this code theoretically still should work shouldn't
it?

Jamie

$fn = 180;
e = 0.001;
f = 0.25;

module dual_bushing_holder() {
union() {
// body
difference() {
cylinder(d=15,h=40);
translate([0,0,-1]) #cylinder(d=14,h=42);
}

    // left middle tab
    difference() {
        hull() {
            translate([-14.5,-1,18.25]) cube([e,2,3.5]);
            translate([-7.5+f,-1,8.5]) cube([e,2,23]);
        }
        // screw hole
        translate([-11.25,-2,20]) rotate([-90,0,0]) cylinder(d=3.3,h=4);
    }

    // right upper tab
    difference() {
        hull() {
            translate([7.5-f,-1,25]) cube([e,2,15]);
            translate([14.5,-1,32.25]) cube([e,2,7.75]);

        }
        // screw hole
        translate([11.25,-2,35.25]) rotate([-90,0,0]) cylinder(d=3.3,h=4);
    }

    // right lower tab
    difference() {
        hull() {
            translate([7.5-f,-1,0]) cube([e,2,15]);
            translate([14.5,-1,0]) cube([e,2,7.75]);

        }
        // screw hole
        translate([11.25,-2,4.75]) rotate([-90,0,0]) cylinder(d=3.3,h=4);
    }
}

}

dual_bushing_holder();

Also fine in dev previews 2018.01.x and 2018.04.x for Windows 64

nice code, btw.

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

That happens to me now and then. I think the version I have is 2018
(something).
What seems to fix it is resizing the rendering window

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

Thanks all for the responses. I neglected to say I'm using Ubuntu
16.04 and the latest OpenSCAD nightly from t-paul's repo.

Exploring more, preview sometimes works but isn't 100% reliable for me.

For example I can save the file, quit OpenSCAD, open the file again,
and the preview works fine. However if I then press F6 to render then
F5 to preview, the shape disappears.

I'll experiment more with polyhedrons and in some Windows VMs I have.
Maybe it's a Linux-only problem.

Jamie