Added initial Fractal Tree demo tutorial. Still need to gen images.

This commit is contained in:
Revar Desmera 2020-03-22 01:14:26 -07:00
parent b2a2c00604
commit c78eade2f2
4 changed files with 200 additions and 44 deletions

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include <BOSL2/std.scad>
include <BOSL2/paths.scad>
include <BOSL2/beziers.scad>
module leaf(s) {
path = [
[0,0], [1.5,-1],
[2,1], [0,3], [-2,1],
[-1.5,-1], [0,0]
];
xrot(90)
linear_sweep_bezier(
scale_points(path, [s,s]/2),
height=0.02
);
}
module branches(minsize, s1, s2){
if(s2>minsize) {
module tree(l=1500, sc=0.7, depth=10)
recolor("lightgray")
cylinder(l=l, d1=l/5, d2=l/5*sc)
attach(TOP)
zrot(gaussian_rands(90,20)[0])
zrot_copies(n=floor(log_rands(2,5,4)[0]))
zrot(gaussian_rands(0,5)[0])
yrot(gaussian_rands(30,10)[0]) {
sc = gaussian_rands(0.7,0.05)[0];
cylinder(d1=s2, d2=s2*sc, l=s1)
branches(minsize, s1*sc, s2*sc);
}
} else {
if (depth>0)
zrot(90)
zrot_copies(n=2)
yrot(30) tree(depth=depth-1, l=l*sc, sc=sc);
else
recolor("springgreen")
attach(TOP) zrot(90)
leaf(gaussian_rands(100,5)[0]);
}
}
module tree(h, d, minsize) {
sc = gaussian_rands(0.7,0.05)[0];
recolor("lightgray") {
cylinder(d1=d, d2=d*sc, l=h) {
branches(minsize, h, d*sc);
}
}
}
tree(d=300, h=1500, minsize=10);
yscale(0.67)
teardrop(d=l*3, l=1, anchor=BOT, spin=90);
tree();
// vim: noexpandtab tabstop=4 shiftwidth=4 softtabstop=4 nowrap

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include <BOSL2/std.scad>
include <BOSL2/paths.scad>
include <BOSL2/beziers.scad>
module leaf(s) {
path = [
[0,0], [1.5,-1],
[2,1], [0,3], [-2,1],
[-1.5,-1], [0,0]
];
xrot(90)
linear_sweep_bezier(
scale_points(path, [s,s]/2),
height=0.02
);
}
module branches(minsize, s1, s2){
if(s2>minsize) {
attach(TOP)
zrot(gaussian_rands(90,20)[0])
zrot_copies(n=floor(log_rands(2,5,4)[0]))
zrot(gaussian_rands(0,5)[0])
yrot(gaussian_rands(30,10)[0]) {
sc = gaussian_rands(0.7,0.05)[0];
cylinder(d1=s2, d2=s2*sc, l=s1)
branches(minsize, s1*sc, s2*sc);
}
} else {
recolor("springgreen")
attach(TOP) zrot(90)
leaf(gaussian_rands(100,5)[0]);
}
}
module tree(h, d, minsize) {
sc = gaussian_rands(0.7,0.05)[0];
recolor("lightgray") {
cylinder(d1=d, d2=d*sc, l=h) {
branches(minsize, h, d*sc);
}
}
}
tree(d=300, h=1500, minsize=10);
// vim: noexpandtab tabstop=4 shiftwidth=4 softtabstop=4 nowrap

139
tutorials/Fractal_Tree.md Normal file
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# Fractal Tree Tutorial
### Start with a Tree Trunk
Firstoff, include the BOSL2 library, then add a tapered cylinder for the tree trunk.
```openscad-example
include <BOSL2/std.scad>
cylinder(l=1500, d1=300, d2=210);
```
### Parameterize It
It's easier to adjust a model if you split out the defining parameters.
```openscad-example
include <BOSL2/std.scad>
l = 1500;
sc = 0.7;
cylinder(l=l, d1=l/5, d2=l/5*sc);
```
### Attaching Branches
You can attach branches to the top of the trunk by using `attach()` as a child of the trunk cylinder.
```openscad-example
include <BOSL2/std.scad>
l = 1500;
sc = 0.7;
cylinder(l=l, d1=l/5, d2=l/5*sc) {
attach(TOP) yrot( 30) cylinder(l=l*sc, d1=l/5*sc, d2=l/5*sc*sc);
attach(TOP) yrot(-30) cylinder(l=l*sc, d1=l/5*sc, d2=l/5*sc*sc);
}
```
### Replicate Branches
Instead of attaching each branch individually, you can attach multiple branch copies at once.
```openscad-example
include <BOSL2/std.scad>
l = 1500;
sc = 0.7;
cylinder(l=l, d1=l/5, d2=l/5*sc)
attach(TOP)
zrot_copies(n=2) // Make multiple rotated copies
yrot(30) cylinder(l=l*sc, d1=l/5*sc, d2=l/5*sc*sc);
```
### Make it a Module
Lets make this into a module, for convenience.
```openscad-example
include <BOSL2/std.scad>
module tree(l=1500, sc=0.7)
cylinder(l=l, d1=l/5, d2=l/5*sc)
attach(TOP)
zrot_copies(n=2)
yrot(30) cylinder(l=l*sc, d1=l/5*sc, d2=l/5*sc*sc);
tree();
```
### Use Recursion
Since branches look much like the main trunk, we can make it recursive. Don't forget the termination clause, or else it'll try to recurse forever!
```openscad-example
include <BOSL2/std.scad>
module tree(l=1500, sc=0.7, depth=10)
cylinder(l=l, d1=l/5, d2=l/5*sc)
attach(TOP)
if (depth>0) // Important!
zrot_copies(n=2)
yrot(30) tree(depth=depth-1, l=l*sc, sc=sc);
tree();
```
### Make it Not Flat
A flat planar tree isn't what we want, so lets bush it out a bit by rotating each level 90 degrees.
```openscad-example
include <BOSL2/std.scad>
module tree(l=1500, sc=0.7, depth=10)
cylinder(l=l, d1=l/5, d2=l/5*sc)
attach(TOP)
if (depth>0)
zrot(90) // Bush it out
zrot_copies(n=2)
yrot(30) tree(depth=depth-1, l=l*sc, sc=sc);
tree();
```
### Adding Leaves
Let's add leaves. They look much like squashed versions of the standard teardrop() module, so lets use that.
```openscad-example
include <BOSL2/std.scad>
module tree(l=1500, sc=0.7, depth=10)
cylinder(l=l, d1=l/5, d2=l/5*sc)
attach(TOP)
if (depth>0)
zrot(90)
zrot_copies(n=2)
yrot(30) tree(depth=depth-1, l=l*sc, sc=sc);
else
yscale(0.67)
teardrop(d=l*3, l=1, anchor=BOT, spin=90);
tree();
```
### Adding Color
We can finish this off with some color. The `color()` module will force all it's children and
their descendants to the new color, even if they were colored before. The `recolor()` module,
however, will only color children and decendants that don't already have a color set by a more
nested `recolor()`.
```openscad-example
include <BOSL2/std.scad>
module tree(l=1500, sc=0.7, depth=10)
recolor("lightgray")
cylinder(l=l, d1=l/5, d2=l/5*sc)
attach(TOP)
if (depth>0)
zrot(90)
zrot_copies(n=2)
yrot(30)
tree(depth=depth-1, l=l*sc, sc=sc);
else
recolor("springgreen")
yscale(0.67)
teardrop(d=l*3, l=1, anchor=BOT, spin=90);
tree();
```

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//////////////////////////////////////////////////////////////////////
BOSL_VERSION = [2,0,212];
BOSL_VERSION = [2,0,213];
// Section: BOSL Library Version Functions