Parametric design tutorial. Basically the idea is to build a reference block in a separate file and then insert it as a link (not embedded) into our final model. After, you can modify the reference block and update it in the final model.

After doing some basics, I went to model a kind of scimitar. First, I drew a circle and a normal line in its center to extrude a handle using the "Extrude surface along curve" function. Second, I made the same but with a polycurve and a trapezoid to create the blade.

At this point I still need to narrow the blade, so I drew a triangle-like line aside from the blade and extruded a volume from it with the idea to after intersect both volumes and, finally, obtain the final shape. BUT this didn't work, instead I had to use the CreateSolid function, which ask for two surfaces and generates the body. None of the boolean operations seemed to work, and I'm not sure if this was because this volumes were solid or surfaces (I converted the surfaces to solid too, with no results using the boolean functions).

Source files: link 1

So, the first tutorial I watched is on how to convert a digital origami, made by drawing joint sheets in the 3D space, into a 2D cutting model using the "Smash" function in Rhino. Basically, each 2D part of the 3D origami was made using "Surface from 3 or 4 corner points" function and by enabling "Near", "Point", "Midpoint" and "Vertex" on the Snap Grid menu.

After that I used the "Join" function to generate one unique body from all the drawn planes; then I was able to convert the 3D model into a cuttable 2D model using the "Smash" function, with which I could export the 2D version to a .dwg file.

Source files: link 1, link 2

I've worked with SW for a couple of years and I just wanted to share a couple of thoughts; in my opinion it has one of the easiest to learn and to work with modelling modules, it has kinematics simulations, assembly relations (both static and dynamic), powerful rendering, stress analysis and many other behavior analysis tools.

Yet most of the powerful tools are rather focused on a more hard engineering practices (not that useful to DIY projects). Further more, one of the main downsides I've found on collaborative work with this tool are the constant incompatibilities between each year's versions, you just can't open previous (nor newer) files, as explained here. Finally, it only runs on MS Windows ... anyways, I still love working with SW.

Well, after installing OpenSCAD I went to their site to check the official documentation. The first useful thing I found is their cheat sheet.

One of the main features of softwares as OpenSCAD is their scripting capabilities, which means that learning their coding language is of great relevance. Also, there are some special variables to soften the curves smoothness (see $fn, $fa, $fs in the link before).

To those that have a favorite text editor (as Vim in my case, with this syntax plugin), OpenSCAD provides tools to edit the scripts with third party editors, since you can enabling the "Design->Automatic Reload and Preview" and "View->Hide Editor" options.

So, my intended excercise was to build a kind of egg covered with squamas; thus I started by creating one single squama with the polyhedron() function aligned in the y-axis. After, I made a translation of the single squama in both the y-axis and z-axis (the y-axis with a sinusoid to get the egg-like shape), followed by the squama rotation. Finally, I added a z-axis rotation to complete the overall shape.

Source file links: file 1

So, as I haven't yet defined my final project, I'll proceed to complete an online GIMP tutorial (video above) on how to do a nice wallpaper.

So, the first step after opening the software is to set the image size (1400x900 in my case) and insert a base image as layer ( scale layer to image size). Then, open the upper image and, with the Fuzzy Select Tool, select the white area of the upper image (white area); hen do a Select-Inverse to get the logo and copy it to the base image in a new layer. Resize the upper image's layer to the desired size.

In order to get a blur effect, create a new layer and fill it with the desired blur color ( white in my case) . Then go to the upper image size and select (in the layers list box) Alpha to Selection->Inverse Selection (on the Edit tab) and "Edit->Clear". After, in order to get the blur halo, go to the white layer, do Select->None, Filters->Blur>Gaussian Blur and set the blur ratio as you want (30x30 in my case).

Finally, save your file and export it on the desired format.

So, what I've learnt is that Gimp might not be as confortable as you wish to create images, but it is extremely powerful to manipulate and compose other images.

Source files links: file 1