About this 3D model

[Wiki](https://github.com/davidson16807/relativity.scad/wiki) [Repo](https://github.com/davidson16807/relativity.scad) This OpenSCAD library adds functionality to size, position, and orient objects relative to other geometric primitives. To do so, the library introduces a new set of modules to replace the default geometric primitives in OpenSCAD. These new primitives have the ability to center themselves along any axis, and place their children along any border. So this: cube_h=10; cylinder_d=7; translate([0,0,cube_h/2]){ cube(cube_h, center=true); translate([cube_h/2 + cylinder_d/2,0,0]) cylinder(d=cylinder_d, h=cube_h, center=true); } becomes this: box(10, anchor=[0,0,-1]) align([1,0,0]) rod(d=7, h=$parent_size.z); But the library does more. *Way* more. The library does for OpenSCAD what css does for html. *It seperates presentation from content.* You can build a single module that renders every part of a project as it appears assembled, then create a presentation layer to isolate a printable part using [show](https://github.com/davidson16807/relativity.scad/wiki/CSG-operations#show) or [hide](https://github.com/davidson16807/relativity.scad/wiki/CSG-operations#hide). You can go the opposite way, too - you can define a series of components, then define attachment points for each and use [attach](https://github.com/davidson16807/relativity.scad/wiki/CSG-operations#attach) to pop them into place like lego blocks. Similar [modules](https://github.com/davidson16807/relativity.scad/wiki/CSG-operations) exist for every CSG operation. The modules work with [selectors](https://github.com/davidson16807/relativity.scad/wiki/CSG-operations#selectors) to specify the primitives you want to work with, much like [css](http://www.w3schools.com/cssref/css_selectors.asp) or [jquery](http://www.w3schools.com/jquery/jquery_ref_selectors.asp): //OpenSCAD logo: differed("hole") ball(50) orient([x,y,z]) rod(d=25, h=50, $class="hole"); For more information, check out the [wiki](https://github.com/davidson16807/relativity.scad/wiki)! ##Updates 11/5/2022 The development phase of relativity.scad has completed successfully for sometime now. To make it official: this project will remain in maintenance mode for the foreseeable future. I am still gladly accepting pull requests for fixes and features, however users may have to expect long response times, on par with response times from previous PRs shown in github. If anyone would like to help out in reducing response times by helping to maintain the project, please let me know [here](https://github.com/davidson16807/relativity.scad/issues/22) and I can make arrangements. In the meantime, I have taken several suggestions and pull requests from the past few years and have made a new release. Big thanks goes to [aleung](https://github.com/davidson16807/relativity.scad/pulls?q=is%3Apr+author%3Aaleung) over on github for the PR he made that addressed the many warning messages users get when running on modern versions of OpenSCAD. **1/25/16** Took down the link to the 2014.03 compatible version, since it was causing confusion. **11/26/15** Added new CSS-like operations: `colored()`, `resized()`, and `scaled()`. Also, fixed an issue causing selectors to not correctly interpret parent-child relationships. **3/17/15**: relativity.scad has been updated to make use of new functionality in the 2015.03 version of OpenSCAD. **relativity.scad is no longer compatible with OpenSCAD version 2014.03.** If you wish to continue using 2014.03, the older version of relativity.scad is still available under the Downloads section as "[relativity.2014.03.scad](http://www.thingiverse.com/download:1168738)" **2/14/15**: Implemented support for parent/child and ancestor/descendant relationships in the selector engine. Selectors now enforce whitespace sensitivity. A useful new module has been added, [attach()](https://github.com/davidson16807/relativity.scad/wiki/CSG-operations#attach). This module allows you to invoke the `children()` operator multiple times throughout a module, then specify which instance of `children()` you want to attach to. There is [a new demo](https://github.com/davidson16807/relativity.scad/wiki/Motor-Mount) on the wiki that demonstrates this functionality **1/19/15**: CSG operations can now be assigned a value for `$class`. This enables them to be used by other CSG operations higher up the call stack. `differed()` now accepts `positive` as an optional parameter that defaults to the opposite of negative. Two selector based operations have been introduced, `show()` and `hide()`, with obvious functionality. **12/25/14**: Relativity now borrows code from the [String Theory](http://www.thingiverse.com/thing:526023) library. This enables advanced class selectors in CSG operations such as negation and class union, e.g. `hulled("not(foo)")` or `hide("this,that")`. Syntax for these operations are intended to match documentation for [existing standards](http://www.w3schools.com/jquery/jquery_ref_sele