TL;DR

Processing isn't a software; it is a programing language based on Java and a community. Learning how to wrangle 3D models in Processing can lead to the development of a stand alone piece of software capable of generating STL files based on parameter input by novice users. Or it can enable the creation of sculptures based on data. What Processing is not designed for is banging out one-off models quickly.

At the very least, using Processing to develop 3D models inculcates the coder with an appreciation of all the hard work put into existing 3D software. 

All the code

Start Here

I hadn't played with Processing for a while so the whole process took me 6+ hours worth of work. It will take me the rest of the day to document/comment the code, etc.  

If you aren't sure what the point would be of bothering to learn 3D rendering in Processing, check out some examples of what is possible by way of inspiration. 

• Interactive Vase Suite: http://www.thingiverse.com/thing:6576
• Blobby: http://www.thingiverse.com/thing:6571
• Cookie Cutter: http://www.thingiverse.com/thing:14868
• Anything by Marius Watz: http://www.thingiverse.com/watz

Next read the MakerBot curriculum section on Processing. 

Help can be hard to find because the name of the language is a real word. While doing this write up I found one 3rd party video overview on 3D in Processing but I haven't watched the whole thing:  Processing Tutorial 5 - Basic 3D by by Joseph Boston

The 4 main 3D libraries for processing are:

• Shapes 3D
• ModelBuilder
• Hemesh 
• toxiclibs

I only used 2 of them in my 4 step process to make a workable file to print from. 

Step 1: Shapes 3D Library

Shapes 3D library has a javadoc reference online and the S3D4P_Showcase example included with the library is very useful. I appropriated it for my first attempt at a model. It requires the PeasyCam Library. 

The problem I ran into repeatedly is that the Yogurt Cup SIP is not a solid primitive, it is a hollow primitive with a wall thickness. If I was adding up solid primitives building a model would have been much easier.

Cylinders in the S3D4P are called Tubes and the visibility of their ends can be turned on and off.

iBasket.drawMode(Shape3D.SOLID, Tube.E_CAP);
iBasket.drawMode(Shape3D.WIRE, Tube.S_CAP);
boolean vis = false;
iBasket.visible(vis, Tube.S_CAP);
//iBasket.visible(vis, Tube.BOTH_CAP) //turn them both off 

First thing I made two nested baskets, one each for the interior and exterior walls. The gap between them indicated the wall thickness. After I got that far I realized I had no idea how to punch a hole for drainage. 

The next approach was making a collection of tubes, but I wasn't sure how to go about connecting them up, so I moved on to see if the primitives in a different library were better.

• Double baskets code
• Floating tubes code

Step 2: ModelBuilder Library

The ModelBuilder library has some primitives associated with it, but more importantly it will export information held within an instance of it's UGeometry object to an STL file.

The examples are robust but not heavily commented. That is why I started with Shapes3D. I couldn't parse what I was looking at initially but with one round under my belt the example code became clearer. I used the mb_02_primatives_01 example as my start point. 

With the ModelBuilder primitives I stalled in the exact same place as I did with Shapes3D. I could only figure out how to make a collection of unattached cylinders. The interior wall isn't lining up correctly. I didn't bother to fix it. 

• Code for the cylinders

Step 3: Building my own primitives

I found an excellent tutorial by Jan Vantomme on how to roll your own 3D primitives (specifically a cone). The Learning section of the Processing site also has an example of implementing vertices as a cylinder and there is an alternative method for building a cylinder on the Processing wiki. Vantomme's, however is the clearest. 

I used his example to write my own primitives using vertices ( See beginShape() and vertex() ) that aren't just shells but have thicknesses.

• void drawThickCylinder( int sides, float r1, float r2, float h, float t)  
• void drawCup( int sides, float r1, float r2, float h, float t)
• void drawDrainCup( int sides, float r1, float r2, float h, float t, float d)
• void drawDrainCupWithLip( int sides, float r1, float r2, float h, float t, float d, float l)

Not the cleverest of names but they work.

• Custom primitives code

Step 4: Combine my own primitives back over to ModelBuilder

Since I was so close I decided to go all the way and integrate drawDrainCupWithLip with the mb_01_vertexlist_03_ribbon3D  ModelBuilder library example.  That function became buildDrainCupWithLip().

The first version of the code actually rendered a number of the surfaces inside-out. I know because I snuck a peak in MeshLab which will be the topic of the next post. The first two pictures are what the model looked like with inside out faces. The third and fourth pictures are of the final fix. 

The rules for making faces that actually face the right direction:

• For upward faces: draw out to in
• For downward faces: draw in to out
• For outward walls: draw bottom to top
• For inward walls: draw top to bottom

• The fixed and working code

The Stats

The stats seem hardly fair given how unique Processing is in this context, but I'll give a stab.

TL;DR

I'm really glad I went back and tried Wings3D. It is an OpenSource GUI based modeler that is relatively easy to use and intuitive. Documentation is lacking, but there is enough to get started and stay interested.  Wings3D also supports the most input and output formats of all the software tested. 

3D Model as a .wings file and STL file

Other People's Videos

The documentation is pretty thin. I did find an old version of the documentation, but mostly I hunted on YouTube.

Start with this one

Wings3d basics - User Interface

Watch with the sound off

3D Modeling - Part I: Navigation in Wings 3D

3D Modeling - Part II: Deformation in Wings 3D

3D Modeling - Part III: Deformation in Wings 3D (Cont.)

Others

Wings 3D demo: Round Hole in Rectangular Solid

Start of a Christmas Tree demo

Mine

Keyboard shortcuts I don't want to forget

R to return camera to home view

X,Y,Z to snap camera to a dead on view of that axis

G - to select an Edge Ring once a edge is selected -  (Then C to create Edge Loop at the center of the ring)

L - The Edge Loop Select once a vert or edge is selected that is part of a loop

TAB - access numeric editing

5 - toggle from % numeric edit to direct units edit

TL; DR

OpenJsCad is another entry in the "model as programing problem" category. OpenJsCad has more flexibility than OpenSCAD but is currently way less pleasant to use.  OpenJsCad embraces dynamic variables. Even the shapes are variables. OpenSCAD has variables that behave more like glorified constants.  OpenJsCad entered the arena more recently (January 2012) and needs to resolve some interface problems. So while I think in the long run OpenJsCad might prove to be more powerful I didn't enjoy using it as much.

TL;DR
From dowload-to-model in OpenSCAD took about an hour... maybe. Programmers will be doing a serious happy dance. The UI holds a simple three paned window: one window for the code, one for the rendered model and one for debug messages. Just a few commands and a rendering of what's been typed updates in the window. Want to twiddle with the size? Change a number. What more facets? Change a number. OpenSCAD has won a place in my tool chain. At this nacent level models are conceptually created  much as they are in Tinkercad - stacking shapes together, taking other shapes away. (Constructive Solid Geometry) What I really want now is for OpenSCAD and Tinkercad to have a baby. I think the experience gained by manipulating the primitives directly in Tinkercad made knowing what to ask for in OpenSCAD extra easy.  Where OpenSCAD really shines is in how easy it is to change the shapes. The joy of variables! 

TL;DR  Blender has one of the steepest learning curves of any software I've tried to use in a long time. The climb is worth it for the computer savvy if the end goal is to produce a character model that can be used in animations and printed out as action figure. The competitors cost thousands of dollars. Making objects for the real world isn't the problem Blender evolved to solve and it is... quirky... using it to do so. Tutorials can be hard to follow because expert users customize their layouts so much. 3 button mice are not my favorite being a hand switcher, and the software cannot be used without one. So while I don't hate Blender, love that it is open source (C, C++, python) and get why it has a rabid fan base, learning it isn't where I want to spend my time right now. But I made the model, and I'm actually PROUD. Took a lot of work to figure out.

Since there is no official place to share files for Blender I've put everything on GitHub

https://github.com/carlynorama/3DModeling-IntroPosts

(download)

Click here to download:

3D_Printing_Day_5_Picking_a_So.zip (628 KB)

TL;DR  Just easy. Well, "just easy" after watching about 20-30 minutes of intro videos. Everything I wanted to be able to do, I could. With options comes complexity; I had to spend some time strategizing how to approach building the model since there were so many paths that would have worked. The plethora of YouTube videos helped. I would not plop a 6 year old down in front of Google SketchUp, but a computer user who has some familiarity with graphics packages shouldn't have a problem. Oh, and it is a real downloaded software with which I can make files that live only my computer. Didn't even need a login. And it's free. They get-ya in the free version by making the import and export options incredibly lousy. But another plus is the scripting language, so there is a plugin for that.

TL;DR The TInkercad browser-only software is slick, pretty and intuitive. Sadly that makes the absence of some features I want all the more glaring. Someone who hasn't been using graphics software since the 80's might be less high maintenance. The in-app tutorial "Quests" are a great teaching tool.  Way better than just a video. I feel like I'm close to a model that will actually work. If I didn't have alignment issues I think I'd be super happy with it as an intro tool. It doesn't yet have the features to be more than that. They're still pretty new. I'll keep checking back. 

UPDATE: I got some clarifications in the comments from the folks at TInkercad (Man they're on top of things) so I've made some changes to the text. 

Final Model: https://tinkercad.com/things/4LrTWpDIFGG

There are two main features of Tinkercad I think are really interesting. The first is the moveable workplane and the second is that holes are entities. The introductory video is actually a bit hard to find. It lives on youtube and explains both of those features.

Watching this and doing some of the Quests is worth the 5-10 minutes. 

Heads Up: The software saves edits frequently without infinite Undo's. Always "save & close"  then reopen a duplicate at milestones.  - UPDATE - Apparently it does, I just did something glitchy, I'm not even sure what, if I can recreate, I'll let them know - 

I was able to create a model by stacking blocks pretty easily. However, the alignment is eyeballed. I can't get the cylinders to snap into alignment based on their centerpoints. I didn't have this problem in 3DTin because they use a center registration point and Tinkercad's is in a corner. I don't see a way to change that. 

http://tinkercad.tenderapp.com/discussions/problems/250-concentric-circles

I ended up making a second version with a different approach, placing the lip as an overlap on a too-tall cup instead of as a block resting on top. Also I've had more practice eyeballing things in the Tinkercad environment, so it is probably good enough. But I'm not sure my cup, lip and holes are perfectly centered on each other. I'd like to be sure before I waste plastic. It means I will never be confident enough to have a thinner wall. And since I can't explicitly place the center points over the same spot in the x plane numerically, or have an inference engine tell me when I'm dead center I guess I'll have to print it with decently thick walls and use calipers to check.

- UPDATE - They know, they know - 

Both Models Together: https://tinkercad.com/things/dT0u4hwRsGa

Additionally tempering my enthusiasm is how I understand their business model. All usage levels are free. They take a kickback when you print one of your objects through the linked services. That is completely 100% fair. I like it. But when a third party buys a copy of what I've made - do I get a piece of the action, too? For most people this won't be a concern, the volumes are too low to matter. Why begrudge them if you like the software? But if someone makes something that gets really popular?  What happens then? Is that fair? What would be fair? They do let you leave your designs private, but then no one benefits... I'm just not 100% sure they've worked that out.

- UPDATE - Okay, this paragraph is not right. I wrote it based on text on the About Tinkercad page and either my reading comprehension was low or it is different now. There seems to be a Pro version in the works that I don't see how to buy... but I'm looking forward to it! - 

STATS:

Version N/A

Date 4/3/12

Target Demographic

• Ideal Object - Smallish objects done for fun. 
• Ideal User - Learner, low experience fine. 

Access

• OpenSource - No
• Free - Yes
• Premium Version - Not yet?
• Linux Version - N/A
• Browser Based - Yes
• Requires Internet Acces - Yes. At all times. 

Privacy, Community & Learning

• StalkerWare - (UPDATED)  You decide. The user can design without logging in but if you clear your cookies all is lost. The default of all designs public not private, but you can have private files. All cloud stuff is going to have some elements of StalkerWare by defult, but thankfully you can create a login independent of a social software. All files live on the cloud. No local file format / mode if you want to make something totally private. No crack pipes for you!
• Private Files - Yes, but they only live in the cloud. 
• Official Community Repository - Yes, the Tinkercad website lets you browse what other people have done on Tinkercad, also has a publish-to-Thingiverse option.
• Group Editing - Not that I saw, but you can pull a copy of someone else's design into your account with a single button press.
• Instashare - To Twitter, Pinterest, Thngiverse
• Official Tutorials - Excellent. They blow the curve. 
• Community Tutorials - Didn't look at any. Didn't need to. 

Editing

• How many tutorials/videos to build first project - (Intro Video, Some of the Quests) 1 video, optionally beginner quests. All very quick. Low bar. 
• Default Bkg Color - White
• Good for Computer Beginners - Yes
• Requires 3 Button Mouse - No
• Real-world units - Yes, mm only
• Numeric controls - No
• WYSIWYG - Yes
• Scripting - No associated scripting language or text commands. 

Input

• Rasters - No
• 2D Vector - No
• Other 3D files - No

Output

• Direct to STL - Yes
• Adjust scale on output - No, already in mm
• Direct to Printing Service - i.Materialize, Ponoko, Shapeways, Sculpteo

So CRASH Space has a flotilla of MakerBots and I live in a home with two MakerBots. My dirty secret - I have never 3D printed anything.