I have used AutoCAD on and off for the last couple of years and can get most CAD designs completed using it, by hook or crook. Although, not always in the most pleasing of timescales, which doesn't really matter that much as they are generally for non-commercial purposes. 123D Design is a free CAD alternative, although not entirely free, which is also used for 3D modelling.
Today it seems that a lot of the features of AutoCAD have been incorporated into 123D Design. Hence, from what I have read the core engine used to drive AutoCAD is in fact the same one used in 123D Design. To test if this is the case I decided to undertake my next 3D design project using 123D on Mac OS X and make my efforts the subject of this and subsequent posts in this category.
Over the last couple of years and given all the heat being generated by buzz words like 3D printers, Maker etc., AutoDesk have released a whole suite of design tools to accommodate 3D designers that, essentially, do not have a degree in mechanical engineering or related discipline. I made a foray into using 123D a while ago, but immediately reverted back to using AutoCAD, as then it lacked a few features that AutoCAD natively supports.
To investigate using 123D Design again I have given myself the real world task of replicating the design of a wooden manikin in 3D that measures 20cm or 8inches in old money. Why I am doing this will become clear over the net couple of months.
The first thing to do to use 123D Design is to install it by navigating to AutoDesk's website or by typing 123D in Google's search engine. The result of the search should take you to AutoDesk's website, as seen in the screenshot above. There are quite a number of related package, but I haven't investigated any of them yet.
There are a number of download options to choose from involving all the usual suspects. I clicked on the download option for Mac, as this installation is for a Mac Book running Yosemite 10.10.1.
Quite surprisingly this took me to the App Store on my Mac Book, which is okay I suppose, as applications downloaded from the store are generally vetted. However, I was slightly cautious, since the application offers in-app purchases. Ha, I knew it couldn't be free, nothing is free in this world apart from the articles on this website of course. you can read them with no strings attached! Lucky you!
Clicking on the "Get" button downloads the app, after you have authorised it to do so. Once downloaded and installed you are good to go.
Even before downloading the software I decided that I didn't really want to take advantage of the in-app purchases, but was curious to see what they have to offer. The screenshot above shows some of the differences, at the time of writing this article, between the free version and the premium monthly subscription version.
For now I'm quite happy to not even apply for free membership, but if I did according to the screenshot above I would only be able to use my 3D models for non-commercial purposes. Not being happy with this I made a mental note to accelerate the integration of Blender 3D into my project work as Blender is free GNU software.
Using Blender was always on the cards anyway, but 123D Design is more similar to AutoCAD and should make an easier transition away from it. Blender here I come, but not before I have a go at finishing the current task.
Starting the current task meant clicking on the pale blue inverted pyramid, the 123D Design application icon, in LaunchPad. Doing so rewards you with the opportunity to start a "New Project", as seen in the image, above. Now, as the objective of the project is to create a 3D model of a 20cm (8in) wooden manikin with moveable limbs, I clicked on start a new project.
As mentioned at the beginning of this blog post I get most of my 3D designs done by hook or crook and not wanting to disadvantage myself I decided to do the same again for this one. Hence, I firstly scanned the image of the manikin using a standard desktop USB printer, a Canon LIDE 110.
Next, the image was loaded into Adobe Illustrator (1) and converted into a Portable Network Graphics (.png) format file, which I would normally import into AutoCAD and similarly into Blender from the documentation that I have read. Disappointingly, I could not find a way of importing the image into 123D, as the only imported format supported seems to be Scalable Vector Graphics (.SVG) files.
Never mind, I'll do that then. So I saved the image to a .svg file and attempted to import it into to 123D, but 123D wasn't having any of it and summarily declared the import as being empty. Oh well, being more determined that ever now, I next created an outline of the manikin by tracing around the manikin (2) using the pen tool in Illustrator.
Then, as the grid in 123D is blue, as seen in the screenshot below, I changed the colour of the outline to red to contrast the grid. (Clever - Ed). I then ONLY saved the red outline as a .svg file (outline.vg for example), ready for import into 123D.
Importing the design into 123D is a matter of navigating to the Import SVG menu option and in this case I imported the design as a sketch, rather than a solid.
The result of importing the outline can be seen in the screenshot above. (But the outline is not red? - Ed).
The next two stages, of the design process, firstly involved adding some polylines to approximate the location of where the skeleton or armature of the manikin would be relative to the outline. Then, secondly, outline is rotated 90o along the axis that made the manikin "stand" on the grid. Hence, in the screenshot, above, the insert depicts the first stage of the design, while the main drawing shows the results of performing the second step. I should say that all that is being done at this stage is quite experimental.
The next thing I did was to create a circle then extrude it, to prove to myself that I could recreate the cylindrical shapes that could be used to reconstruct the body parts of the manikin. The next stage would be to take the exact measurements of the different parts of the manikin, then use a circular manipulator to taper the cylindrical parts to be more exactly like the shapes of it.
I'm maxed out for time for now and need to go, but more soon. What do I think of 123D Design, today? Well, apart from the issue of importing images, as a graphic file, it's quite good. Although, as intimated previously I will eventually start using Blender. However, for the remainder of this project I will continue using 123D Design, where practicable.
This project fits in with some of the other projects on this site in the so called bigger picture, including Blender algorithm acceleration using, yes you guessed it, FPGAs. All will be revealed in subsequent blog posts. Stay tuned.