Assignment: Week02

COMPUTER-AIDED DESIGN

Assignment: model (raster, vector, 2D, 3D, render, animate, simulate, ...) a possible final project, and post it on your class page

I had several choices for 2D and 3D software which I went through

Gimp

This is one of the softwares I have utilized for almost every week of the class mostly to edit screenshots of my work and resize images.

I use a dual monitor set up so most of my screenshots look something like this...

So, open file in gimp...

Use the 'Rectangle select tool' to select part of screenshot that is needed...

Crop the image using the Crop to Selection tool under the Image menu, i.e. Image > Crop to Selection ...

Export the image as default Gimp file format is .xcf

The final image then looks as shown...

Inkscape

A software I have installed but rarely use. I use it to quickly view and edit vector graphics. I will hopefully learn to fully utilize it in time...

CorelDraw

CorelDraw is the 2D Vector graphics software I am most familiar with. It allows you to import multplie file formats and quickly send them to the laser cutter.

Create shapes....

Shape edit tools...

Welding joins two or more shapes by their intersecting parts...

while trim cuts off the intersecting area of one shape using the shape of the other based on the order of the shapes...

FreeCAD

FreeCAD is an open-source parametric 3D CAD modeler that runs on Linux,Windows and OS X.

OpenSCAD

OpenSCAD is an open-source script-only based modeller available on Linux, Windows and OS X. It's syntax is based on functional programming.

As it is a script-only CAD Software has some programming rules which apply to it e.g

Ending all statements with a semicolon (;)
Characters denoting comments; (//) to comment out a line and (/*...*/) to comment out whole sections.
Functions are called using the following syntax; functionname(variables){...code...}

A full tutorial is available here

Code to create a sphere...

sphere(20);

Code to create a cube...

cube(15);

Both cube and sphere but different objects...

sphere(15);
cube(15)

Centering both sphere and cube...

sphere(15, center=true);
cube(20, center=true);

All objects are by default created with the center (0,0,0) and so to move them away from this default we use the translate() function...

translate([20,20,20])
{
union()
{
sphere(15, center=true);
cube(20, center=true);
}
}

To manipulate solids or objects you use Constructive Solid Geometry (CSG) like;

Union

Merges objects...

translate([-20,0,15])
{
union()
{
sphere(15, center=true);
cube(20, center=true);
}
}

Instersection

Removes parts of the objects not shared/intersecting and keeps all overlapping portions...

intersection()
{
sphere(15, center=true);
cube(20, center=true);
}

Difference

Subtracts the second object (and all further objects) from the first...

translate([40,0,0])
{
difference()
{
sphere(15, center=true);
cube(22, center=true);
}
}

translate([20,0,0])
{
difference()
{
cube(22, center=true);
sphere(15, center=true);
}
}

An example of some CSG modelling

translate([-40,0,0])
{
union()
{
sphere(15, center=true);
cube(20, center=true);
}
}

intersection()
{
sphere(15, center=true);
cube(20, center=true);
}

translate([40,0,0])
{
difference()
{
cube(22, center=true);
sphere(15, center=true);
}
}