How does one get started with procedural generation? - procedural-generation

Procedural generation has been brought into the spotlight recently (by Spore, MMOs, etc), and it seems like an interesting/powerful programming technique.
My questions are these:
Do you know of any mid-sized projects that utilize procedural generation techniques?
What language/class of languages is best for procedural generation?
Can you use procedural generation for "serious" code? (i.e., not a game)

You should probably start with a little theory and simple examples such as the midpoint displacement algorithm. You should also learn a little about Perlin Noise if you are interested in generating graphics. I used this to get me started with my final year project on procedural generation.
Fractals are closely related to procedural generation.
Terragen and SpeedTree will show you some amazing possibilities of procedural generation.
Procedural generation is a technique that can be used in any language (it is definitely not restricted to procedural languages such as C, as it can be used in OO languages such as Java, and Logic languages such as Prolog). A good understanding of recursion in any language will strengthen your grasp of Procedural Generation.
As for 'serious' or non-game code, procedural generation techniques have been used to:
simulate the growth of cities in order to plan for traffic management
to simulate the growth of blood vessels
SpeedTree is used in movies and architectural presentations

Procedural Content Generation wiki:
http://pcg.wikidot.com/
if what you want isn't on there, then add it ;)

Procedural content generation is now all written for the GPU, so you'll need to know a shader language. That means GLSL or HLSL. These are languages tied to OpenGL and DirectX respectively.
While my personal preference is for Dx11 / HLSL due to speed, an easier learning curve and Frank D Luna, OpenGL is supported on more platforms.
You should also check out WebGL if you want to jump right into writing shaders without having to spend the (considerable) time it takes to setup an OpenGL / DirectX game engine.
Procedural content starts with noise.
So you'll need to learn about Perlin noise (and its successor Simplex noise).
Shadertoy is a superb reference for learning about shader programming. I would recommend you come to it once you've given shader coding a go yourself, as the code there is not for the mathematically squeamish, but that is how procedural content is done.
Shadertoy was created by a procedural genius, Inigo Quilez, a product of the demo scene who works at Pixar. He has some youtube videos (great example) of live coding sessions and I can also recommend these.

Procedural generation is used heavily in the demoscene to create complex graphics in a small executable. Will Wright even said that he was inspired by the demoscene while making Spore. That may be your best place to start.
http://en.wikipedia.org/wiki/Demoscene

There is an excellent book about the topic:
http://www.amazon.com/Texturing-Modeling-Third-Procedural-Approach/dp/1558608486
It is biased toward non-real-time visual effects and animation generation, but the theory and ideas are usable outside of these fields, I suppose.
It may also worth to mention that there is a professional software package that implements a complete procedural workflow called SideFX's Houdini. You can use it to invent and prototype procedural solutions to problems, that you can later translate to code.
While it's a rather expensive package, it has a free evaluation licence, which can be used as a very nice educational and/or engineering tool.

If you want an example of a world generator simulation plates tectonics, erosion, rain-shadow, etc. take a look at:
https://github.com/ftomassetti/lands
On top of that there is also a civilizations evolution simulator:
https://github.com/ftomassetti/civs
A blog full on interesting resource is:
dungeonleague.com/
It is abandoned now but you should read all its posts

I'm not an expert on this, but I can try and contribute a few answers:
NetHack and it's brethern are open source and rely heavily on procedural generation of levels (maps). Link to the downloads of it.
If you are more interested in landscape/texture/cloud generation, I'd recommend you search Gamasutra and GameDev which have quite a few articles on those subjects.
AFAIK I don't think there is much difference between languages. Most of the code you see will be in C/CPP because it's still very much the official language of Game Developers, but you can use anything you want...
Well it depends if you have a project that can benefit from such technology. I saw procedural generation used in simulators for the army (which can be considered a game, although they are not very playable :)).
And a small note - my definition if procedural generation is anything generating a lot of data from a small amount of rules or patterns and lots of randomness, your results may vary :)

(More than 10 years later ...)
Procedural generation only means that code is used to generate the data instead of it being hand made. For example if you want to generate a forest with various trees you are not going to design each tree by hand, thus coding is more efficient to generate the variations. It could be the generation of the tree graphics, size, structure, placement ...
In general there is some kind of interation with a few rules, in addition to that you can add some randomness and logic of your own, combine all of these techniques ...
Anything somewhat chaotic but not too chaotic can yield interesting results.
Here are a few notable techniques:
https://en.wikipedia.org/wiki/Cellular_automaton
https://en.wikipedia.org/wiki/Conway%27s_Game_of_Life (notable cellular automaton)
Book: https://en.wikipedia.org/wiki/A_New_Kind_of_Science
Fractals: https://en.wikipedia.org/wiki/Fractal
Plants: https://en.wikipedia.org/wiki/L-system
Terrain or maps, textures, smoke, clouds, turbulence: https://en.wikipedia.org/wiki/Perlin_noise
Terrain or maps: https://en.wikipedia.org/wiki/Voronoi_diagram
A few games famous for their procedural generation:
https://en.wikipedia.org/wiki/Rogue_(video_game) and roguelikes in general
https://en.wikipedia.org/wiki/Elite_(video_game) random seed ...
https://en.wikipedia.org/wiki/.kkrieger The entire game uses only 97,280 bytes of disk space.
Video tutorial about Procedural Landmass Generation.
Conference on procedural content generation for games, has a lot of videos on the topic: everythingprocedural
Have fun.

the most important thing is to analyze how roads, cities, blocks and buildings are structured. find out what all eg buildings have in common. look at photos, maps, plans and reality. if you do that you will be one step ahead of people who consider city building as a merely computer-technological matter.
next you should develop solutions on how to create that geometry in tiny, distinct steps. you have to define rules that make up a believable city. if you are into 3d modelling you have to rethink a lot of what you have learned so the computer can follow your instructions in any situation.
in order to not loose track you should set up a lot of operators that are only responsible for little parts of the whole process. that makes debugging, expanding and improving your system much easier. in the next step you should link those operators and check the results by changing parameters.
i have seen too many "city generators" that mainly consist of random-shaped boxes with some window textures on them : (

Answering "Do you know of any mid-sized projects that utilize procedural generation techniques?" - the Wilder World project is a Web3, virtual world being created that utilizes procedural generation techniques to create the NFT assets and I believe the virtual world which will be created using UnReal Engine. Visit wilderworld.com for the main site or zine.wilderworld.com for more info.

Related

Approach to designing large functional programs

I've been reading lots on functional languages and would like to maybe play with re-writing some parts of my application in F#. Is it better to design from the outside in or the inside out?
One of the influental works on the subject of FP Why Functional Programming Matters by John Hughes can be considered as a direct answer:
Our ability to decompose
a problem into parts depends directly on our ability to glue solutions
together. To support modular programming, a language must provide good
glue. Functional programming languages provide two new kinds of glue —
higher-order functions and lazy evaluation. Using these glues one can modularize
programs in new and useful ways, and we’ve shown several examples of this.
Smaller and more general modules can be reused more widely, easing subsequent
programming. This explains why functional programs are so much smaller and
easier to write than conventional ones. It also provides a target for functional
programmers to aim at. If any part of a program is messy or complicated, the
programmer should attempt to modularize it and to generalize the parts. He or
she should expect to use higher-order functions and lazy evaluation as the tools
for doing this.
I would also recommend looking at contemporary interview with John Hughes in InfoQ.
One article that really helped me come to terms with functional programming is this one:
http://prog21.dadgum.com/23.html
It is a tutorial for how to create a Pac-Man clone using functional-programming techniques. I don't even recognize the language he used (it might have been Erlang,) but the explanation helped me understand the correct mindset which I used when rewriting one of my programs in Scheme.
I'm not an expert at all on this subject, but here is a link to an article on this subject, by 'our' very own Brian:
How does functional programming affect the structure of your code?
And some questions from SO & Programmers (where - incidentally - I suspect this question would be a better fit)
Real world pitfalls of introducing F# into a large codebase and engineering team
How to organize F# source of large project (>300 classes) in Visual Studio?
Not sure I understand what is meant by "inside out" / "outside in", but FP is most useful "in the small" -- at the function level. OO is probably still the best way to organize projects in the large. It's easiest to deal with objects that correlate with your business domain.
I guess by outside in you mean top to bottom approach and by inside out you mean from bottom to top. If this is what you mean than FP is more suited towards bottom up approach i.e inside out.
While designing FP programs think about solving the problem using:
Data Structure : What all data your application needs to handle and
which data structure is most suitable to represent that data.
Function : A function does one thing (and do it correctly).
Composition : Create new functions which achieve their goals by composing other functions using technique like higher order functions and compositions.
Other more advance and abstract FP techniques like Monads etc.
So basically you start from bottom, for each atomic problem you write a function and then as you move upward in the design you use these atomic function to create functions at higher level using composition.
Remember always think of solving problem using abstractions and composition of those abstraction rather than thinking sequentially as you would do in a imperative programming.

Pac-Man Game: Processing Programming Language & ActionScript

I'll simply title this in concordance with my Pac-Man game that I want to make.
I was suggested to perhaps start with a programming language or platform that uses less overhead than, say, DirectX. I can agree to that, especially because then I can focus on the design of the game rather than the implementation- something I think is more important at this stage.
I was wondering what merits Processing has as a language capable of creating simple games. The creation of images seems almost trivially easy, which allows me a lot of play-room to mess with the algorithms. However, I wanted to know if the language is suited for a game and possibly resource-intensive code?
At first glance, this looks almost like a simplified version of Actionscript, a language that tries to easily produce images. ActionScript is something I have already programmed in, but do not like. The language, for some reason, isn't that appealing to me. Processing isn't so much either but I feel the image processing capabilities of this make it outweigh my negative view of the syntax.
So my question is, what are the people's experience with Processing, and am I really justified in comparing it to ActionScript? Is it suitable for creating games at all? I figure with all the comfort and ease I have creating images, I feel the speed of the program as a whole would be decreased, especially when I introduce algorithms.
Furthermore, if it is suitable for creating a simple pac-man game, should I try ActionScript instead anyway?
Well, you're not only choosing languages, but also choosing platforms here. AS3 means FlashPlayer, Processing means JVM. I don't think processing has to necessarily needs to turn out slower, or faster. In the case of pacman, this is all a matter of rendering speed. I don't know what Processing uses for rendering, but if it is jOGL, it is possible to outperform FlashPlayer (depending on the kind of graphics).
I think, the core question is, where you want to be going with the game. If it is just a prototype, both flash and processing are good tools, each having its own strengths and weaknesses. If you really want this to be a long shot, then you also should consider several factors:
Due to Flash's market penetration and a big gaming (and game developement) community:
Flash probably is a better platform for both distribution.
There's a number of flash game engines (also dealing with multiplayer etc.) out there, whereas I found similar engines to build on in Processing impossible to find.
From what I can tell, AS3 is a more "serious" language, aiming for developement of applications, whereas Processing focuses on fast prototyping and image processing.
Now another question is, what you don't like in both AS3 and Processing. Personally, I switched to Haxe, which proved to leverage the FlashPlayer better than AS3 does, and is a far more expressive and elegant language. However, since I don't know what your exact problem is, I cannot really give you advice.
after years of using processing, i can say that the language imposed itself as the canvas language with implementations in js, python and ruby.
if you like the canvas, you'll maybe understand the simplicity of it
a line is drawn with only
line(x1,x2,y1,y2);
compare this with native js or python syntax
as such, processing allows you to focus more on ideas rather than struggling with platform specific concept
numerous games have been produced with it both on the browser and in desktop.
compared to action script, i feel that processing is far more cross platformed and user friendly which makes unleashing your creativity a painless job !

Is medical imaging a separate programming specialty?

Sorry if it's yet another question with no response:), feel free to close. There's a bunch of questions on SO like: does technology/language/database used in medicine is quite different from that used in traditional area like banking/industry etc. You can hear in response or 1) no difference 2) it's vague and hard according to lack of standards.
But medical imaging is attractive not only due to general concerns: humanistic & scientific. Job opportunities are strict and obvious. C++/Сom/ActiveX/C#, some open source libraries, DICOM/HL7, Python. It looks like a separate specialty - you don't need to explain on interview what exactly you did.
So my question is: Is medical imaging a separate specialty as it seems to stranger? Do the vendors mostly go in the same direction and you can change them without changing world view as it happens in enterprise? Or it is just kind of C++ programming which is usually interchanged with some other image processing, trading, drivers, op. system programming etc.?
I would say that programming is universal. Whether you're developing a web application or designing for an embedded system, you will face similar challenges. However, some aspects do change. And in this case, I would say that the focus on algorithms is what sets medical imaging apart from other fields.
I'm not an expert, but there is definitely some advanced math and algorithms involved in medical imaging. For example, consider image registration - a common algorithm used in the field. Not only would an MI expert have to have a good mathematical understanding of the registration, but he would also have to be able to readily implement and optimize it - not a trivial task.

Compilers and beyond

I want to go backwards and learn more about how compilers, processors and memory operate on my programs. I am also interested in the physics on which all of this depends. Any good references or books would be appreciated...
For compilers, the ultimate book is the Dragon Book, aka Principles of Compiler Design. It is a bit heavy going at first, but it becomes easier with each pass you make at it. It's a classic and should be read by all serious students of programming/computer science.
My first suggestion was going to be Code which has been suggested already. A better, but harder, book on the subject of processors is Computer Organization & Design by Hennessey & Patterson. You might look for an older edition on Amazon or Half.com. They'll be a lot cheaper and have basically the same information.
These will both teach you the basics of how a processor works, assembly language, etc. This will help you understand how your program will be interpreted and thus, what sort of performance bottlenecks might exist based on your design.
It sounds to me like you want to get a Computer Science degree. :-)
The simplest introduction , and very well written is Code by Charles Petzold
alt text http://ecx.images-amazon.com/images/I/31t68r9K28L._BO2,204,203,200_PIsitb-sticker-arrow-click,TopRight,35,-76_AA240_SH20_OU01_.jpg
I don't normally think of physics and compilers at the same time.
This link might get you thinking.
Write a simple emulator for something like C64. By thinking of how to emulate the CPU, Memory and other Chips you will learn how these simple machines worked. Today's computers pretty much operate in the same manner with a lot more complexity but the basic idea is the same.
Your emulator doesnt have to be super fast - try and get the C64 welcome message up and if you did your code right - you should be able to POKE and write basic programs and have them work :)
10 PRINT "DONT LISTEN TO ME - APPLE //E's RULE"
20 GOTO 10
I would suggest learning enough assembler to be able to write a simple Hello World program in assembler.
This will teach you exactly how the CPU works at the register and memory level.
It will also give you a good introduction into how source code is converted to object files and how the linker brings together all these object files together to create a working program.
Pick up any of the Hennessy & Patterson books.
Computer Architecture - A Quantitative Approach or Computer Organization & Design - The Hardware Interface
Feynman has a nice bit on the Physics of Computation:
which addresses the second part of your question.
Pick up a book on "Computer Organization" or "Computer Architecture" on Amazon. This is what we used when I was in college. It's not too thick, and will give you the basics, from the gate level all of the way up to how memory is organized and programs are written. If, after this, you want to look deeper into the physics, then you'll want to pick up a book on semiconductor physics. (But if I were you I'd just start by looking up "logic gate", "diode", and "transistor" on wikipedia!)
If you really want to get into the physics of processors/ IC's, you need to have a solid electromagnetics/circuit analysis background. It's certainly not easy stuff, and won't really make you a better programmer. If you're really interested, borrow some books from an EE friend!
An abstraction up from that is the gate level, which programmers can usually grok since it's all about logic.
I made a similar resolution after reading Steve Yegge's recommendation to learn about compilers. I've been really enjoying Nisan and Schocken's The Elements of Computing Systems: Building a Modern Computer from First Principles which is first a textbook, second, a one-semester course for freshmen or seniors, and third, a website providing the lectures and cross-platform emulation-simulation software: http://www1.idc.ac.il/tecs/ (TECS)
The topics go from NAND (programming digital logic circuits in HDL), up through flip-flops, ALUs and registers, assemblers, parsing and compilers, operating systems, and GUIs. You, the student, implements every one of these topics on the hardware simulator or software emulator provided on the website. To me, it is a celebration of human ingenuity that this range of ideas can be so deeply covered in 3--4 months by undergrads. One of the authors/professors gave a Google Tech Talk on the subject that's worth checking out if you have an hour to spare away from their course.
I can't recommend an equally-compelling resource for the physics of computation, but I can perfunctorily say that my electrical engineering department's first two core EE courses students could take (simultaneously if they chose) were Circuits 1 and Semiconductors 1. The former dealt with voltage, current, inductors, capacitors, op amps, etc.---while the latter dealt with quantum mechanics, crystals, doping, charge carriers, etc., and most directly spoke to the physics of digital processing and storage devices. It's difficult for me to imagine a hands-on simulation environment like TECS for such a topic, though, making it more appropriate for academic than hobbyist/professional study?

Textual versus Graphical Programming Languages [closed]

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I am part of a high school robotics team, and there is some debate about which language to use to program our robot. We are choosing between C (or maybe C++) and LabVIEW. There are pros for each language.
C(++):
Widely used
Good preparation for the future (most programming positions require text-based programmers.)
We can expand upon our C codebase from last year
Allows us to better understand what our robot is doing.
LabVIEW
Easier to visualize program flow (blocks and wires, instead of lines of code)
Easier to teach (Supposedly...)
"The future of programming is graphical." (Think so?)
Closer to the Robolab background that some new members may have.
Don't need to intimately know what's going on. Simply tell the module to find the red ball, don't need to know how.
This is a very difficult decision for us, and we've been debating for a while. Based on those pros for each language, and on the experience you've got, what do you think the better option is? Keep in mind that we aren't necessarily going for pure efficiency. We also hope to prepare our programmers for a future in programming.
Also:
Do you think that graphical languages such as LabVEIW are the future of programming?
Is a graphical language easier to learn than a textual language? I think that they should be about equally challenging to learn.
Seeing as we are partailly rooted in helping people learn, how much should we rely on prewritten modules, and how much should we try to write on our own? ("Good programmers write good code, great programmers copy great code." But isn't it worth being a good programmer, first?)
Thanks for the advice!
Edit:
I'd like to emphasize this question more:
The team captain thinks that LabVIEW is better for its ease of learning and teaching. Is that true? I think that C could be taught just as easily, and beginner-level tasks would still be around with C. I'd really like to hear your opinions. Is there any reason that typing while{} should be any more difficult than creating a "while box?" Isn't it just as intuitive that program flows line by line, only modified by ifs and loops, as it is intuitive that the program flows through the wire, only modified by ifs and loops!?
Thanks again!
Edit:
I just realized that this falls under the topic of "language debate." I hope it's okay, because it's about what's best for a specific branch of programming, with certain goals. If it's not... I'm sorry...
Before I arrived, our group (PhD scientists, with little programming background) had been trying to implement a LabVIEW application on-and-off for nearly a year. The code was untidy, too complex (front and back-end) and most importantly, did not work. I am a keen programmer but had never used LabVIEW. With a little help from a LabVIEW guru who could help translate the textual progamming paradigms I knew into LabVIEW concepts it was possible to code the app in a week. The point here is that the basic coding concepts still have to be learnt, the language, even one like LabVIEW, is just a different way of expressing them.
LabVIEW is great to use for what it was originally designed for. i.e. to take data from DAQ cards and display it on-screen perhaps with some minor manipulations in-between. However, programming algorithms is no easier and I would even suggest that it is more difficult. For example, in most procedural languages execution order is generally followed line by line, using pseudo mathematical notation (i.e. y = x*x + x + 1) whereas LabVIEW would implement this using a series of VI's which don't necessarily follow from each other (i.e. left-to-right) on the canvas.
Moreover programming as a career is more than knowing the technicalities of coding. Being able to effectively ask for help/search for answers, write readable code and work with legacy code are all key skills which are undeniably more difficult in a graphical language such as LabVIEW.
I believe some aspects of graphical programming may become mainstream - the use of sub-VIs perfectly embodies the 'black-box' principal of programming and is also used in other language abstractions such as Yahoo Pipes and the Apple Automator - and perhaps some future graphical language will revolutionise the way we program but LabVIEW itself is not a massive paradigm shift in language design, we still have while, for, if flow control, typecasting, event driven programming, even objects. If the future really will be written in LabVIEW, C++ programmer won't have much trouble crossing over.
As a postcript I'd say that C/C++ is more suited to robotics since the students will no doubt have to deal with embedded systems and FPGAs at some point. Low level programming knowledge (bits, registers etc.) would be invaluable for this kind of thing.
#mendicant Actually LabVIEW is used a lot in industry, especially for control systems. Granted NASA unlikely use it for on-board satellite systems but then software developement for space-systems is a whole different ball game...
I've encountered a somewhat similar situation in the research group I'm currently working in. It's a biophysics group, and we're using LabVIEW all over the place to control our instruments. That works absolutely great: it's easy to assemble a UI to control all aspects of your instruments, to view its status and to save your data.
And now I have to stop myself from writing a 5 page rant, because for me LabVIEW has been a nightmare. Let me instead try to summarize some pros and cons:
Disclaimer I'm not a LabVIEW expert, I might say things that are biased, out-of-date or just plain wrong :)
LabVIEW pros
Yes, it's easy to learn. Many PhD's in our group seem to have acquired enough skills to hack away within a few weeks, or even less.
Libraries. This is a major point. You'd have to carefully investigate this for your own situation (I don't know what you need, if there are good LabVIEW libraries for it, or if there are alternatives in other languages). In my case, finding, e.g., a good, fast charting library in Python has been a major problem, that has prevented me from rewriting some of our programs in Python.
Your school may already have it installed and running.
LabVIEW cons
It's perhaps too easy to learn. In any case, it seems no one really bothers to learn best practices, so programs quickly become a complete, irreparable mess. Sure, that's also bound to happen with text-based languages if you're not careful, but IMO it's much more difficult to do things right in LabVIEW.
There tend to be major issues in LabVIEW with finding sub-VIs (even up to version 8.2, I think). LabVIEW has its own way of knowing where to find libraries and sub-VIs, which makes it very easy to completely break your software. This makes large projects a pain if you don't have someone around who knows how to handle this.
Getting LabVIEW to work with version control is a pain. Sure, it can be done, but in any case I'd refrain from using the built-in VC. Check out LVDiff for a LabVIEW diff tool, but don't even think about merging.
(The last two points make working in a team on one project difficult. That's probably important in your case)
This is personal, but I find that many algorithms just don't work when programmed visually. It's a mess.
One example is stuff that is strictly sequential; that gets cumbersome pretty quickly.
It's difficult to have an overview of the code.
If you use sub-VI's for small tasks (just like it's a good practice to make functions that perform a small task, and that fit on one screen), you can't just give them names, but you have to draw icons for each of them. That gets very annoying and cumbersome within only a few minutes, so you become very tempted not to put stuff in a sub-VI. It's just too much of a hassle. Btw: making a really good icon can take a professional hours. Go try to make a unique, immediately understandable, recognizable icon for every sub-VI you write :)
You'll have carpal tunnel within a week. Guaranteed.
#Brendan: hear, hear!
Concluding remarks
As for your "should I write my own modules" question: I'm not sure. Depends on your time constraints. Don't spend time on reinventing the wheel if you don't have to. It's too easy to spend days on writing low-level code and then realize you've run out of time. If that means you choose LabVIEW, go for it.
If there'd be easy ways to combine LabVIEW and, e.g., C++, I'd love to hear about it: that may give you the best of both worlds, but I doubt there are.
But make sure you and your team spend time on learning best practices. Looking at each other's code. Learning from each other. Writing usable, understandable code. And having fun!
And please forgive me for sounding edgy and perhaps somewhat pedantic. It's just that LabVIEW has been a real nightmare for me :)
I think the choice of LabVIEW or not comes down to whether you want to learn to program in a commonly used language as a marketable skill, or just want to get stuff done. LabVIEW enables you to Get Stuff Done very quickly and productively. As others have observed, it doesn't magically free you from having to understand what you're doing, and it's quite possible to create an unholy mess if you don't - although anecdotally, the worst examples of bad coding style in LabVIEW are generally perpetrated by people who are experienced in a text language and refuse to adapt to how LabVIEW works because they 'already know how to program, dammit!'
That's not to imply that LabVIEW programming isn't a marketable skill, of course; just that it's not as mass-market as C++.
LabVIEW makes it extremely easy to manage different things going on in parallel, which you may well have in a robot control situation. Race conditions in code that should be sequential shouldn't be a problem either (i.e. if they are, you're doing it wrong): there are simple techniques for making sure that stuff happens in the right order where necessary - chaining subVI's using the error wire or other data, using notifiers or queues, building a state machine structure, even using LabVIEW's sequence structure if necessary. Again, this is simply a case of taking the time to understand the tools available in LabVIEW and how they work. I don't think the gripe about having to make subVI icons is very well directed; you can very quickly create one containing a few words of text, maybe with a background colour, and that will be fine for most purposes.
'Are graphical languages the way of the future' is a red herring based on a false dichotomy. Some things are well suited to graphical languages (parallel code, for instance); other things suit text languages much better. I don't expect LabVIEW and graphical programming to either go away, or take over the world.
Incidentally, I would be very surprised if NASA didn't use LabVIEW in the space program. Someone recently described on the Info-LabVIEW mailing list how they had used LabVIEW to develop and test the closed loop control of flight surfaces actuated by electric motors on the Boeing 787, and gave the impression that LabVIEW was used extensively in the plane's development. It's also used for real-time control in the Large Hadron Collider!
The most active place currently for getting further information and help with LabVIEW, apart from National Instruments' own site and forums, seems to be LAVA.
This doesn't answer you question directly, but you may want to consider a third option of mixing in an interpreted language. Lua, for example, is already used in the robotics field. It's fast, light-weight and can be configured to run with fixed-point numbers instead of floating-point since most microcontrollers don't have an FPU. Forth is another alternative with similar usage.
It should be pretty easy to write a thin interface layer in C and then let the students loose with interpreted scripts. You could even set it up to allow code to be loaded dynamically without recompiling and flashing a chip. This should reduce the iteration cycle and allow students to learn better by seeing results more quickly.
I'm biased against using visual tools like LabVIEW. I always seem to hit something that doesn't or won't work quite like I want it to do. So, I prefer the absolute control you get with textual code.
LabVIEW's other strength (besides libraries) is concurrency. It's a dataflow language, which means that the runtime can handle concurrency for you. So if you're doing something highly concurrent and don't want to have to do traditional synchronization, LabVIEW can help you there.
The future doesn't belong to graphical languages as they stand today. It belongs to whoever can come up with a representation of dataflow (or another concurrency-friendly type of programming) that's as straightforward as the graphical approach is, but is also parsable by the programmer's own tools.
There is a published study of the topic hosted by National Instruments:
A Study of Graphical vs. Textual Programming for Teaching DSP
It specifically looks at LabVIEW versus MATLAB (as opposed to C).
I think that graphical languages wil always be limited in expressivity compared to textual ones. Compare trying to communicate in visual symbols (e.g., REBUS or sign language) to communicating using words.
For simple tasks, using a graphical language is usually easier but for more intricate logic, I find that graphical languages get in the way.
Another debate implied in this argument, though, is declarative programming vs. imperative. Declarative is usually better for anything where you really don't need the fine-grained control over how something is done. You can use C++ in a declarative way but you would need more work up front to make it so, whereas LABView is designed as a declarative language.
A picture is worth a thousand words but if a picture represents a thousand words that you don't need and you can't change that, then in that case a picture is worthless. Whereas, you can create thousands of pictures using words, specifying every detail and even leading the viewer's focus explicitly.
LabVIEW lets you get started quickly, and (as others have already said) has a massive library of code for doing various test, measurement & control related things.
The single biggest downfall of LabVIEW, though, is that you lose all the tools that programmers write for themselves.
Your code is stored as VIs. These are opaque, binary files. This means that your code really isn't yours, it's LabVIEW's. You can't write your own parser, you can't write a code generator, you can't do automated changes via macros or scripts.
This sucks when you have a 5000 VI app that needs some minor tweak applied universally. Your only option is to go through every VI manually, and heaven help you if you miss a change in one VI off in a corner somewhere.
And yes, since it's binary, you can't do diff/merge/patch like you can with textual languages. This does indeed make working with more than one version of the code a horrific nightmare of maintainability.
By all means, use LabVIEW if you're doing something simple, or need to prototype, or don't plan to maintain your code.
If you want to do real, maintainable programming, use a textual language. You might be slower getting started, but you'll be faster in the long run.
(Oh, and if you need DAQ libraries, NI's got C++ and .Net versions of those, too.)
My first post here :) be gentle ...
I come from an embedded background in the automotive industry and now i'm in the defense industry. I can tell you from experience that C/C++ and LabVIEW are really different beasts with different purposes in mind. C/C++ was always used for the embedded work on microcontrollers because it was compact and compilers/tools were easy to come by. LabVIEW on the other hand was used to drive the test system (along with test stand as a sequencer). Most of the test equipment we used were from NI so LabVIEW provided an environment where we had the tools and the drivers required for the job, along with the support we wanted ..
In terms of ease of learning, there are many many resources out there for C/C++ and many websites that lay out design considerations and example algorithms on pretty much anything you're after freely available. For LabVIEW, the user community's probably not as diverse as C/C++, and it takes a little bit more effort to inspect and compare example code (have to have the right version of LabVIEW etc) ... I found LabVIEW pretty easy to pick up and learn, but there a nuisances as some have mentioned here to do with parallelism and various other things that require a bit of experience before you become aware of them.
So the conclusion after all that? I'd say that BOTH languages are worthwhile in learning because they really do represent two different styles of programming and it is certainly worthwhile to be aware and proficient at both.
Oh my God, the answer is so simple. Use LabView.
I have programmed embedded systems for 10 years, and I can say that without at least a couple months of infrastructure (very careful infrastructure!), you will not be as productive as you are on day 1 with LabView.
If you are designing a robot to be sold and used for the military, go ahead and start with C - it's a good call.
Otherwise, use the system that allows you to try out the most variety in the shortest amount of time. That's LabView.
I love LabVIEW. I would highly recommend it especially if the other remembers have used something similar. It takes a while for normal programmers to get used to it, but the result's are much better if you already know how to program.
C/C++ equals manage your own memory. You'll be swimming in memory links and worrying about them. Go with LabVIEW and make sure you read the documentation that comes with LabVIEW and watch out for race conditions.
Learning a language is easy. Learning how to program is not. This doesn't change even if it's a graphical language. The advantage of Graphical languages is that it is easier to visual what the code will do rather than sit there and decipher a bunch of text.
The important thing is not the language but the programming concepts. It shouldn't matter what language you learn to program in, because with a little effort you should be able to program well in any language. Languages come and go.
Disclaimer: I've not witnessed LabVIEW, but I have used a few other graphical languages including WebMethods Flow and Modeller, dynamic simulation languages at university and, er, MIT's Scratch :).
My experience is that graphical languages can do a good job of the 'plumbing' part of programming, but the ones I've used actively get in the way of algorithmics. If your algorithms are very simple, that might be OK.
On the other hand, I don't think C++ is great for your situation either. You'll spend more time tracking down pointer and memory management issues than you do in useful work.
If your robot can be controlled using a scripting language (Python, Ruby, Perl, whatever), then I think that would be a much better choice.
Then there's hybrid options:
If there's no scripting option for your robot, and you have a C++ geek on your team, then consider having that geek write bindings to map your C++ library to a scripting language. This would allow people with other specialities to program the robot more easily. The bindings would make a good gift to the community.
If LabVIEW allows it, use its graphical language to plumb together modules written in a textual language.
I think that graphical languages might be the language of the future..... for all those adhoc MS Access developers out there. There will always be a spot for the purely textual coders.
Personally, I've got to ask what is the real fun of building a robot if it's all done for you? If you just drop a 'find the red ball' module in there and watch it go? What sense of pride will you have for your accomplishment? Personally, I wouldn't have much. Plus, what will it teach you of coding, or of the (very important) aspect of the software/hardware interface that is critical in robotics?
I don't claim to be an expert in the field, but ask yourself one thing: Do you think that NASA used LabVIEW to code the Mars Rovers? Do you think that anyone truly prominent in robotics is using LabView?
Really, if you ask me, the only thing using cookie cutter things like LabVIEW to build this is going to prepare you for is to be some backyard robot builder and nothing more. If you want something that will give you something more like industry experience, build your own 'LabVIEW'-type system. Build your own find-the-ball module, or your own 'follow-the-line' module. It will be far more difficult, but it will also be way more cool too. :D
You're in High School. How much time do you have to work on this program? How many people are in your group? Do they know C++ or LabView already?
From your question, I see that you know C++ and most of the group does not. I also suspect that the group leader is perceptive enough to notice that some members of the team may be intimidated by a text based programming language. This is acceptable, you're in high school, and these people are normies. I feel as though normal high schoolers will be able to understand LabView more intuitively than C++. I'm guessing most high school students, like the population in general, are scared of a command line. For you there is much less of a difference, but for them, it is night and day.
You are correct that the same concepts may be applied to LabView as C++. Each has its strengths and weaknesses. The key is selecting the right tool for the job. LabView was designed for this kind of application. C++ is much more generic and can be applied to many other kinds of problems.
I am going to recommend LabView. Given the right hardware, you can be up and running almost out-of-the-box. Your team can spend more time getting the robot to do what you want, which is what the focus of this activity should be.
Graphical Languages are not the future of programming; they have been one of the choices available, created to solve certain types of problems, for many years. The future of programming is layer upon layer of abstraction away from machine code. In the future, we'll be wondering why we wasted all this time programming "semantics" over and over.
how much should we rely on prewritten modules, and how much should we try to write on our own?
You shouldn't waste time reinventing the wheel. If there are device drivers available in Labview, use them. You can learn a lot by copying code that is similar in function and tailoring it to your needs - you get to see how other people solved similar problems, and have to interpret their solution before you can properly apply it to your problem. If you blindly copy code, chances of getting it to work are slim. You have to be good, even if you copy code.
Best of luck!
I would suggest you use LabVIEW as you can get down to making the robot what you want to do faster and easier. LabVIEW has been designed with this mind. OfCourse C(++) are great languages, but LabVIEW does what it is supposed to do better than anything else.
People can write really good software in LabVIEW as it provides ample scope and support for that.
There is one huge thing I found negative in using LabVIEW for my applications: Organize design complexity. As a physisist I find Labview great for prototyping, instrument control and mathematical analysis. There is no language in which you get faster and better a result then in LabVIEW. I used LabView since 1997. Since 2005 I switched completely to the .NET framework, since it is easier to design and maintain.
In LabVIEW a simple 'if' structure has to be drawn and uses a lot of space on your graphical design. I just found out that many of our commercial applications were hard to maintain. The more complex the application became, the more difficult it was to read.
I now use text laguages and I am much better in maintaining everything. If you would compare C++ to LabVIEW I would use LabVIEW, but compared to C# it does not win
As allways, it depends.
I am using LabVIEW since about 20 years now and did quite a large kind of jobs, from simple DAQ to very complex visualization, from device controls to test sequencers. If it was not good enough, I for sure would have switched. That said, I started coding Fortran with punchcards and used a whole lot of programming languages on 8-bit 'machines', starting with Z80-based ones. The languages ranged from Assembler to BASIC, from Turbo-Pascal to C.
LabVIEW was a major improvement because of its extensive libraries for data acqusition and analysis. One has, however, to learn a different paradigma. And you definitely need a trackball ;-))
I don't anything about LabView (or much about C/C++), but..
Do you think that graphical languages such as LabVEIW are the future of programming?
No...
Is a graphical language easier to learn than a textual language? I think that they should be about equally challenging to learn.
Easier to learn? No, but they are easier to explain and understand.
To explain a programming language you have to explain what a variable is (which is surprisingly difficult). This isn't a problem with flowgraph/nodal coding tools, like the LEGO Mindstroms programming interface, or Quartz Composer..
For example, in this is a fairly complicated LEGO Mindstroms program - it's very easy to understand what is going in... but what if you want the robot to run the INCREASEJITTER block 5 times, then drive forward for 10 seconds, then try the INCREASEJITTER loop again? Things start getting messy very quickly..
Quartz Composer is a great exmaple of this, and why I don't think graphical languages will ever "be the future"
It makes it very easy to really cool stuff (3D particle effects, with a camera controlled by the average brightness of pixels from a webcam).. but incredibly difficult to do easy things, like iterate over the elements from an XML file, or store that average pixel value into a file.
Seeing as we are partailly rooted in helping people learn, how much should we rely on prewritten modules, and how much should we try to write on our own? ("Good programmers write good code, great programmers copy great code." But isn't it worth being a good programmer, first?)
For learning, it's so much easier to both explain and understand a graphical language..
That said, I would recommend a specialised text-based language language as a progression. For example, for graphics something like Processing or NodeBox. They are "normal" languages (Processing is Java, NodeBox is Python) with very specialised, easy to use (but absurdly powerful) frameworks ingrained into them..
Importantly, they are very interactive languages, you don't have to write hundreds of lines just to get a circle onscreen.. You just type oval(100, 200, 10, 10) and press the run button, and it appears! This also makes them very easy to demonstrate and explain.
More robotics-related, even something like LOGO would be a good introduction - you type "FORWARD 1" and the turtle drives forward one box.. Type "LEFT 90" and it turns 90 degrees.. This relates to reality very simply. You can visualise what each instruction will do, then try it out and confirm it really works that way.
Show them shiney looking things, they will pickup the useful stuff they'd learn from C along the way, if they are interested or progress to the point where they need a "real" language, they'll have all that knowledge, rather than run into the syntax-error and compiling brick-wall..
It seems that if you are trying to prepare our team for a future in programming that C(++) ma be the better route. The promise of general programming languages that are built with visual building blocks has never seemed to materialize and I am beginning to wonder if they ever will. It seems that while it can be done for specific problem domains, once you get into trying to solve many general problems a text based programming language is hard to beat.
At one time I had sort of bought into the idea of executable UML but it seems that once you get past the object relationships and some of the process flows UML would be a pretty miserable way to build an app. Imagine trying to wire it all up to a GUI. I wouldn't mind being proven wrong but so far it seems unlikely we'll be point and click programming anytime soon.
I started with LabVIEW about 2 years ago and now use it all the time so may be biased but find it ideal for applications where data acquisition and control are involved.
We use LabVIEW mainly for testing where we take continuous measurements and control gas valves and ATE enclosures. This involves both digital and analogue input and outputs with signal analysis routines and process control all running from a GUI. By breaking down each part into subVIs we are able to reconfigure the tests with the click and drag of the mouse.
Not exactly the same as C/C++ but a similar implementation of measurement, control and analysis using Visual BASIC appears complex and hard to maintain by comparision.
I think the process of programming is more important than the actual coding language and you should follow the style guidelines for a graphical programming language. LabVIEW block diagrams show the flow of data (Dataflow programming) so it should be easy to see potential race conditions although I've never had any problems. If you have a C codebase then building it into a dll will allow LabVIEW to call it directly.
There are definitely merits to both choices; however, since your domain is an educational experience I think a C/C++ solution would most benefit the students. Graphical programming will always be an option but simply does not provide the functionality in an elegant manner that would make it more efficient to use than textual programming for low-level programming. This is not a bad thing - the whole point of abstraction is to allow a new understanding and view of a problem domain. The reason I believe many may be disappointed with graphical programming though is that, for any particular program, the incremental gain in going from programming in C to graphical is not nearly the same as going from assembly to C.
Knowledge of graphical programming would benefit any future programmer for sure. There will probably be opportunities in the future that only require knowledge of graphical programming and perhaps some of your students could benefit from some early experience with it. On the other hand, a solid foundation in fundamental programming concepts afforded by a textual approach will benefit all of your students and surely must be the better answer.
The team captain thinks that LabVIEW
is better for its ease of learning and
teaching. Is that true?
I doubt that would be true for any single language, or paradigm. LabView could surely be easier for people with electronics engineering background; making programs in it is "simply" drawing wires. Then again, such people might already be exposed to programming, as well.
One essential difference - apart from from the graphic - is that LV is demand based (flow) programming. You start from the outcome and tell, what is needed to get to it. Traditional programming tends to be imperative (going the other way round).
Some languages can provide the both. I crafted a multithreading library for Lua recently (Lanes) and it can be used for demand-based programming in an otherwise imperative environment. I know there are successful robots run mostly in Lua out there (Crazy Ivan at Lua Oh Six).
Have you had a look at the Microsoft Robotics Studio?
http://msdn.microsoft.com/en-us/robotics/default.aspx
It allows for visual programming (VPL):
http://msdn.microsoft.com/en-us/library/bb483047.aspx
as well as modern languages such as C#.
I encourage you to at least take a look at the tutorials.
My gripe against Labview (and Matlab in this respect) is that if you plan on embedding the code in anything other than x86 (and Labview has tools to put Labview VIs on ARMs) then you'll have to throw as much horsepower at the problem as you can because it's inefficient.
Labview is a great prototyping tool: lots of libraries, easy to string together blocks, maybe a little difficult to do advanced algorithms but there's probably a block for what you want to do. You can get functionality done quickly. But if you think you can take that VI and just put it on a device you're wrong. For instance, if you make an adder block in Labview you have two inputs and one output. What is the memory usage for that? Three variables worth of data? Two? In C or C++ you know, because you can either write z=x+y or x+=y and you know exactly what your code is doing and what the memory situation is. Memory usage can spike quickly especially because (as others have pointed out) Labview is highly parallel. So be prepared to throw more RAM than you thought at the problem. And more processing power.
In short, Labview is great for rapid prototyping but you lose too much control in other situations. If you're working with large amounts of data or limited memory/processing power then use a text-based programming language so you can control what goes on.
People always compare labview with C++ and day "oh labview is high level and it has so much built in functionality try acquiring data doing a dfft and displaying the data its so easy in labview try it in C++".
Myth 1: It's hard to get anything done with C++ its because its so low level and labview has many things already implemented.
The problem is if you are developing a robotic system in C++ you MUST use libraries like opencv , pcl .. ect and you would be even more smarter if you use a software framework designed for building robotic systems like ROS (robot operating system). Therefore you need to use a full set of tools. Infact there are more high level tools available when you use, ROS + python/c++ with libraries such as opencv and pcl. I have used labview robotics and frankly commonly used algorithms like ICP are not there and its not like you can use other libraries easily now.
Myth2: Is it easier to understand graphical programming languages
It depends on the situation. When you are coding a complicated algorithm the graphical elements will take up valuable screen space and it will be difficult to understand the method. To understand labview code you have to read over an area that is O(n^2) complexity in code you just read top to bottom.
What if you have parallel systems. ROS implements a graph based architecture based on subcriber/publisher messages implemented using callback and its pretty easy to have multiple programs running and communicating. Having individual parallel components separated makes it easier to debug. For instance stepping through parallel labview code is a nightmare because control flow jumps form one place to another. In ROS you don't explicitly 'draw out your archietecture like in labview, however you can still see it my running the command ros run rqt_graph ( which will show all connected nodes)
"The future of programming is graphical." (Think so?)
I hope not, the current implementation of labview does not allow coding using text-based methods and graphical methods. ( there is mathscript , however this is incredibly slow)
Its hard to debug because you cant hide the parallelism easily.
Its hard to read labview code because there you have to look over so much area.
Labview is great for data aq and signal processing but not experimental robotics, because most of the high level components like SLAM (simultaneous localisation and mapping), point cloud registration, point cloud processing ect are missing. Even if they do add these components and they are easy to integrate like in ROS, because labview is proprietary and expensive they will never keep up with the open source community.
In summary if labview is the future for mechatronics i am changing my career path to investment banking... If i can't enjoy my work i may as well make some money and retire early...

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