I'm newbie in programming world especially in webots.
Do you guys have any ideas/tutorial to move e-puck robot to a specific position in webots?
In my case, I'm trying to move the e-puck robot to the start position and when the robot finish performing wall following behavior, it will stop at the same position as start.
I'm searching for the ideas/tutorial to solve the problem, but in the end, I'm stuck. Can anyone help me?
Thank you.
I recommend you to take a look at the e-puck curriculum for Webots, particularly at the advanced part:
http://en.wikibooks.org/wiki/Cyberbotics%27_Robot_Curriculum/Advanced_Programming_Exercises
The idea is the following: if you would like to do this in real conditions, implementing the odometry of the robot is a first step. A "goto" function based on the odometry would be the second step. The link contains information about this.
Ultimately, taking care of the other sensors (distance sensors, etc.) is the best solution, but it requires to do "SLAM". In this case, you can link your controller with a SLAM library (e.g. gmapping or Karto):
http://en.wikipedia.org/wiki/Simultaneous_localization_and_mapping
If you don't care about realism, you can get the absolute coordinates of the robot (using a Supervisor, or a GPS+Compass device). Writing a "goto" function on this is trivial.
How can I increase the animation speed in Corona? Changing the sprite.timeScale property makes the animation restart.
I don't have an answer for the first question, but for the 2nd ones, we know the forum search is borked and we are in the process of fixing it, but in the mean time, your best search results come from Google. Do your google search like:
site:coronalabs.com magic formula
and that will give you the best search results until the problem gets solved.
I am looking for some advice on categorizing a library of sound effects. I have a large set of random sound effects, (think whistles, pops, growls, creaks, gunshots etc). I would like to be able to take a growl for example, and find the next growl that sounds the closest to the original.
Given a sound, what sound from my set sounds the closest to it.
I have done a fair amount of googling and have found two avenues that I am still researching. One is using echonest, although their "best match" support looks not promising for public users. The other option is diving into FFT and building my own matching algorithm. This is a fine option and would be a great learning experience but I wanted to get some opinions from others who might know a little more about sound processing; especially short clips .5sec - 3sec range, not full length music.
Thanks!
I have worked in movie postproduction for years and as far as I know, there is no way to do that automatically. Every file has meta information in its file header which describes what the sound is like. You are then actually not searching for the file names but in the meta string.
I don't think that it is trivial to sort effects programmatically as two effects that sound similar might be totally different if you look at the waveform.
You would need to extract significant information about a sound that you can then compare.
I am also not a DSP expert, maybe there are methods to do this
If you're interested in trying to build your own system to do this, I can suggest a few keywords that might help to refine your Google searches. In the academic research community, the task you're describing is often called "content-based audio searching". I know there's been a lot of work done on it, and though most pertains to music, sound effects have definitely been the focus of a number of studies.
You might want to start with the work of Pedro Cano.
Also, I recently heard about a company that's doing similar work. You might want to check out products from Imagine Research.
Those are just a couple of ideas off the top of my head. I'm not %100 sure they'll be helpful. If they are, please let me know!
Now that Wolfram Alpha is released, I am interested in finding out if it can be used as a time-saver in daily programming.
What would you use Wolfram Alpha to do, that earlier took you more time to do manually?
I guess the "Web and Computer systems"-examples is a good start, but there must be more hidden gems that will be really practical for us programmers.
A short list of examples:
MD5-hashing / SHA-hashing
Quick lockup of unicode and HTML-codes for symbols
Color-codes
Please only include one search query per answer, then we can rate them to get the best ones to the top.
(I made this one a community-wiki, since we will be using the voting for ranking)
Note: If some of the links in the answers don't work (eg: wolfram doesn't find any results, then replace all + with spaces..
I might 'save time' by not playing around with it and doing real work instead. :)
Calculating lift coefficients of NACA profiles (example).
(I made a program for this, but it's nice to have the option to do it quick)
I probably won't use it for anything. I don't know about you, but I deal with enough black boxes on a daily basis, and I'd rather use the ones that have been tried and tested thoroughly.
This might come back to haunt me later, but it strikes me that although there might be a point to WA used in a mechanical manner, from my perspective I'm thinking it's not the hard calculable information questions which are the problem which needs to be solved, it's the soft human data which defies classification or rigid modelling. Google seem to understand this, not sure Stephen Wolfram does.
OTOH it could be that anyone can be Colin Laney now.
Someone double check me here:
The MD5 hash of "Wolfram Alpha" (no quotes) is:
882b 0be2 79eb 7e88 86cd 3dae 19c1 d267
And not:
a615 9984 9aee b7be 3091 68bc 0ab7 ?
EDIT: The hash changes every time given the same query...what kind of hash is this?
http://www14.wolframalpha.com/input/?i=MD5%22Wolfram+Alpha%22
I am in the process of developping a game, and after two months of work (not full time mind you), I have come to realise that our specs for the game are lacking a lot of details. I am not a professional game developper, this is only a hobby.
What I would like to receive help or advices for is this: What are the major components that you find in games, that have to be developped or already exists as librairies? The objective of this question is for me to be able to specify more game aspects.
Currently, we had specified pretty much only how we would work on the visual, completely forgetting everything about game logic (AI, Entities interactions, Quest logic (how do we decide whether or not a quest is completed)).
So far, I have found those points:
Physics (collision detection, actual forces, etc.)
AI (pathfinding, objectives, etc.)
Model management
Animation management
Scene management
Combat management
Inventory management
Camera (make sure not to render everything that is in the scene)
Heightmaps
Entities communication (Player with NPC, enemy, other players, etc)
Game state
Game state save system
In order to reduce the scope of this queston, I'd like it if you could specifically discuss aspects related to developping an RPG type of game. I will also point out that I am using XNA to develop this game, but I have almost no grasp of all the classes available yet (pretty much only using the Game component with some classes that are related to it such as GameTime, SpriteBatch, GraphicDeviceManager) but not much more.
You have a decent list, but you are missing storage (save load), text (text is important in RPGs : Unicode, font rendering), probably a macro system for text (something that replaces tokens like {player} with the player characters name), and most important of all content generation tools (map editor, chara editor, dialog editor) because RPGs need content (or auto generation tools if you need ). By the way have links to your work?
I do this exact stuff for a living so if you need more pointers perhaps I can help.
I don't know if this is any help, but I have been reading articles from http://www.gamasutra.com/ for many years.
I don't have a perfect set of tools from the beginning, but your list covers most of the usual trouble for RUNNING the game. But have you found out what each one of the items stands for? How much have you made already? "Inventory Management" sounds very heavy, but some games just need a simple "array" of objects. Takes an hour to program + some graphical integration (if you have your GUI Management done already).
How to start planning
When I develop games in my spare time, I usually get an idea because another game lacks this function/option. Then I start up what ever development tool I am currently using and try to see if I can make a prototype showing this idea. It's not always about fancy graphics, but most often it's more about finding out how to solve a certain problem. Green and red boxes will help you most of the way, but otherwise, use Google Images and do a quick search for prototype graphics. But remember that these images are probably copyrighted, so only use them for internal test purposes and to explain to your graphic artists what type of game/graphic you want to make.
Secondly, you'll find that you need to find/build tools to create the "maps/missions/quests" too. Today many develop their own "object script" where they can easily add new content/path to a game.
Many of the ideas we (my friends and I) have been testing started with a certain prototype of the interface, to see if its possible to generate that sort of screen output first. Then we build a quick'n'dirty map/level-editor that can supply us with test maps.
No game logic at this point, still figuring out if the game-engine in general is running.
My first game-algorithm problem
Back when I was in my teens I had a Commodore 64 and I was wondering, how do they sort 10 numbers in order for a Highscore? It took me quite a while to find a "scalable" way of doing this, but I learned a lot about programming too.
The second problem I found
How do I make a tank/cannon fire a bullet in the correct direction when I fly my helicopter around the screen?
I sat down and drew quick sketches of the actual problem, looked at the bullet lines, tried some theories of my own and found something that seemed to be working (by dividing and multiplying positions etc.) later on in school I discovered this to be more or less Pythagoras. LOL!
Years and many game attempts later
I played "Dune" and the later C&C + the new game Warcraft (v1/v2) - I remember it started to annoyed me how the lame AI worked. The path finding algorithms were frustrating for the player, I thought. They moved in direction of target position and then found a wall, but if the way was to complex, the object just stopped. Argh!
So I first sat with large amounts of paper, then I tried to draw certain scenarios where an "object" (tank/ork/soldier) would go from A to B and then suddenly there was a "structure" (building/other object) in the pathway - what then?
I learned about A-star pathfinding (after solving it first on my own in a similar way, then later reading about the reason for this working). A very "cpu heavy" way of finding a path, but I learned a lot from the process of "cracking this nut". These thoughts have helped me a lot developing other game algortimes over time.
So what I am saying is: I think you'll have to think more of:
How is the game to be played?
What does the user experience look like?
Why would the user want to come back to the game?
What requirements are needed? Broadband? 19" monitor with 1280x1024?
An RPG, yes - but will it be multi-user or single?
Do we need a fast network/server setup or do we need to develop a strong AI for the NPCs?
And much more...
I am not sure this is what you asked for, but I hope you can use it somehow?
There are hundreds of components needed to make a game, from time management to audio. You'll probably need to roll your own GUI, as native OS controls are very non-gamey. You will probably also need all kinds of tools to generate your worlds, exporters to convert models and textures into something suitable for your game etc.
I would strongly recommend that you start with one of the many free or cheap game engines that are out there. Loads of them come with the source code, so you can learn how they have been put together as you go.
When you think you are ready, you can start to replace parts of the engine you are using to better suit your needs.
I agree with Robert Gould's post , especially about tools and I'd also add
Scripting
Memory Management
Network - especially replication of game object states and match-making
oh and don't forget Localisation - particularly for text strings
Effects and effect timers (could be magical effects, could just be stuff like being stunned.)
Character professions, skills, spells (if that kind of game).
World creation tools, to make it easy for non-programmer builders.
Think about whether or not you want PvP. If so, you need to really think about how you're going to do your combat system and any limits you want on who can attack whom.
Equipment, "treasure", values of things and how you want to do the economy.
This is an older question, but IMHO now there is a better answer: use Unity (or something akin to it). It gives you 90% of what you need to make a game up front, so you can jump in and focus directly on the part you care about, which is the gameplay. When you run aground because there's something it doesn't do out of the box, you can usually find a resource in the Asset Store for free or cheap that will save you a lot of work.
I would also add that if you're not working on your game full-time, be mindful of the complexity and the time-frame of the task. If you'll try to integrate so many different frameworks into your RPG game, you can easily end up with several years worth of work; maybe it would be more advisable to start small and only develop the "core" of your game first and not bother about physics, for example. You could still add it in the second version.