Tutorial fixes.

This commit is contained in:
Garth Minette 2021-12-06 14:28:36 -08:00
parent 21083277b0
commit 4cb59d988e
3 changed files with 16 additions and 16 deletions

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@ -958,7 +958,7 @@ stellate_cube() show_anchors(50);
```openscad-3D ```openscad-3D
$fn=32; $fn=32;
R = difference(circle(10), right(2, circle(9))); R = difference(circle(10), right(2, circle(9)));
linear_sweep(R,height=10,anchor_isect=true) linear_sweep(R,height=10,atype="hull")
attach(RIGHT) anchor_arrow(); attach(RIGHT) anchor_arrow();
``` ```

View file

@ -151,7 +151,7 @@ stroke(path, closed=true, endcap2="arrow2");
``` ```
```openscad-2D ```openscad-2D
path = oval(d=[50,30]); path = ellipse(d=[50,30]);
stroke(path, closed=true, endcap2="arrow2"); stroke(path, closed=true, endcap2="arrow2");
``` ```

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@ -164,7 +164,7 @@ circle(d=100);
circle(d=100, $fn=8); circle(d=100, $fn=8);
``` ```
The BOSL2 library also provides an enhanced equivalent of `circle()` called `oval()`. The BOSL2 library also provides an enhanced equivalent of `circle()` called `ellipse()`.
You can use it in the same way you use `circle()`, but it also provides extended You can use it in the same way you use `circle()`, but it also provides extended
functionality. For example, it allows more control over its size and orientation. functionality. For example, it allows more control over its size and orientation.
@ -172,22 +172,22 @@ Since a circle in OpenSCAD can only be approximated by a regular polygon with
a number of straight sides, this can lead to size and shape inaccuracies. a number of straight sides, this can lead to size and shape inaccuracies.
To counter this, the `realign=` and `circum=` arguments are also provided. To counter this, the `realign=` and `circum=` arguments are also provided.
The `realign=` argument, if set `true`, rotates the `oval()` by half the angle The `realign=` argument, if set `true`, rotates the `ellipse()` by half the angle
between the sides: between the sides:
```openscad-2D ```openscad-2D
oval(d=100, $fn=8, realign=true); ellipse(d=100, $fn=8, realign=true);
``` ```
The `circum=` argument, if true, makes it so that the polygon forming the The `circum=` argument, if true, makes it so that the polygon forming the
`oval()` circumscribes the ideal circle instead of inscribing it. `ellipse()` circumscribes the ideal circle instead of inscribing it.
Inscribing the ideal circle: Inscribing the ideal circle:
```openscad-2D ```openscad-2D
difference() { difference() {
circle(d=100, $fn=360); circle(d=100, $fn=360);
oval(d=100, $fn=8); ellipse(d=100, $fn=8);
} }
``` ```
@ -195,39 +195,39 @@ Circumscribing the ideal circle:
```openscad-2D ```openscad-2D
difference() { difference() {
oval(d=100, $fn=8, circum=true); ellipse(d=100, $fn=8, circum=true);
circle(d=100, $fn=360); circle(d=100, $fn=360);
} }
``` ```
The `oval()` module, as its name suggests, can be given separate X and Y radii The `ellipse()` module, as its name suggests, can be given separate X and Y radii
or diameters. To do this, just give `r=` or `d=` with a list of two radii or or diameters. To do this, just give `r=` or `d=` with a list of two radii or
diameters: diameters:
```openscad-2D ```openscad-2D
oval(r=[30,20]); ellipse(r=[30,20]);
``` ```
```openscad-2D ```openscad-2D
oval(d=[60,40]); ellipse(d=[60,40]);
``` ```
Another way that `oval()` is enhanced over `circle()`, is that you can anchor, Another way that `ellipse()` is enhanced over `circle()`, is that you can anchor,
spin and attach it. spin and attach it.
```openscad-2D ```openscad-2D
oval(r=50, anchor=BACK); ellipse(r=50, anchor=BACK);
``` ```
```openscad-2D ```openscad-2D
oval(r=50, anchor=FRONT+RIGHT); ellipse(r=50, anchor=FRONT+RIGHT);
``` ```
Using spin on a circle may not make initial sense, until you remember that Using spin on a circle may not make initial sense, until you remember that
anchoring is performed before spin: anchoring is performed before spin:
```openscad-2D ```openscad-2D
oval(r=50, anchor=FRONT, spin=-30); ellipse(r=50, anchor=FRONT, spin=-30);
``` ```
@ -349,7 +349,7 @@ They also have somewhat different attachment behavior:
```openscad-2D ```openscad-2D
color("green") stroke(circle(d=50), closed=true); color("green") stroke(circle(d=50), closed=true);
oval(d=50,$fn=5) ellipse(d=50,$fn=5)
attach(LEFT) color("blue") anchor_arrow2d(); attach(LEFT) color("blue") anchor_arrow2d();
``` ```