by West Games
From the developers of the cult hit S.T.A.L.K.E.R. series, comes a new post apocalyptic video game called Areal.
Funding for this project was suspended by Kickstarter on July 22, 2014.
See full bio
Use this space to cheer the creator along, ask questions, and talk to your fellow backers. Please remember to be respectful and considerate. Thanks!
Ahmad Khan of course I read because you are arguing with me and it was interesting to learn with whom I`m talking about) so I read the name of school common for me, what is the problem?
http://www.incgamers.com/2014/07/areal-ama-at-reddit-does-little-to-reassure-s-t-a-l-k-e-r-fans - Posted on 14th July, 4 days old.
http://www.vg247.com/2014/07/18/areal-video-stalker-doesnt-do-it-any-favours/ - Posted on 18th July, 12 hours old.
http://www.incgamers.com/2014/07/areal-releases-prototype-footage-to-more-accusations - Posted on 18th July, 12 hours old.
http://www.forbes.com/sites/erikkain/2014/07/18/areal-kickstarter-finally-gets-some-gameplay-footage/ - Posted on 18th July, 12 hours old.
Well if everyone donates and they run off with the money we will know the truth indeed.
Julia: keep telling yourself that, thats what you get for reading people facebook pages.
still guys let`s donate this project and we all will find out the truth
Ahmad Khan you told me there is another school or another name of the school but not me) I know the WestWood educational establishment and that will do
@Julia:trying to prove smth you could have found it and show me, but still you can not, your own words.
@ Julia Kravec:
One correction on that: the team claiming to spend their own savings. However they have done nothing to prove that they have truly spent their savings on this project even though they could easily prove it if they really have the engine, AI, inventory and part of the missions worked out like they claim.
Monsters from the Id: The Making of Doom
From the very first (January 1994) issue of Game Developer magazine, this retrospective on Id Software's then-contemporary Doom and Wolfenstein 3D paints a unique portrait of a legendary developer whose games would launch a genre.
In an era of where it often takes 20MB to put in all the advertised features, they did it in less than four. At a time where soundcard compatibility was a big problem, they added on Disney Sound Source as an afterthought for demonstrations. As many larger game companies are coming to terms with cross-platform development, to them it comes naturally. They write games that would take larger companies 30 people or more, and the whole company comprises seven people. They are the programmers at Id Software, and what they are doing could change the PC game industry forever.
It was actually Id's previous game, Wolfenstein 3D, that earned its accolades. The premise of Wolfenstein 3D was straight out of a B-movie, where players battles their way out of a Nazi castle. What made Wolfenstein 3D stand out was its brilliant use of bitmapped images, digitized sounds, and blazing speed to give the illusion of a three-dimensional world. Id made use of a technique known as texture mapping that, combined with a raycasting engine written in assembly language, allowed the three-dimensional graphics to be playable on the lowest common denominator machine, at the time a 286.
Perhaps, the most amazing aspect of Wolfenstein 3D had to do with its distribution. It was shareware. Using a time-honored shareware technique, the first 10 levels of Wolfenstein 3D were free. It was the additional levels that were sold directly through the distributor, a shareware game company called Apogee. This allowed people to copy the first part of the game, which was public domain, and see how well the game performed on their machines before they bought the whole game. The free teaser file spread like a virus until it was all over the world, with over 20% of the orders for the complete version coming in from overseas.
Here is where Id has potentially made its biggest impact on the PC game industry. By releasing a state-of-the-art game through shareware, it was able to destroy the old shareware game sales record, set by Id's own Commander Keen series, by over five times. By totaling sales of over 100,000 units by the end of 1993, Id proved that professional-quality games could be successfully marketed via shareware. To truly compare shareware to traditional distribution, six months after the release of Wolfenstein, Id released a revamped version of Wolfenstein called Spear of Destiny. As of late 1993, Spear of Destiny and Wolfenstein had sold 100,000 copies apiece and Wolfenstein sales were still going strong, but Spear of Destiny sales were slipping as it was being forced off of retail shelves by newer games.
However, it's not the sales total that makes this distribution revolutionary, but the profit margin. For example, for every game of Spear of Destiny sold, Id would get about $8.00, half the total return split with the retail distributor FormGen. In the case of a Nintendo cartridge of Wolfenstein, the return would only be about $2.00. But, by using a shareware distribution system, Id was able to recoup the total price of the game minus the actual cost or materials and having an operator to take orders. In the case of Wolfenstein, the cost of materials was less than $5.00, and the complete game cost $50. Although they did split the profit with Apogee, this gave them a profit margin any software company would envy.
Id Software has come a long way from its humble roots in Shreveport, La. It was at a company that made monthly game disks called Softdisk where the majority of the Id development team met. John Romero, one of Id's founders, was forwarded some fan letters that were sent in and tacked them up on the wall in his office. He had never given them a second thought until one day, when he was reading an article in a game magazine about a shareware game called Caverns of Kroz, he noticed a familiar address.
It turned out that Scott Miller, president of Apogee, saw one of the games Romero and his colleagues had created for Softdisk and wanted it for his shareware distribution company. Miller, knowing that all mail to Softdisk would be opened at the front desk, wrote phony fan mail to the programmers under a variety of names and always ended the letters with "please write me at...." When John Romero saw the same address on all the fan mail, he realized he didn't have as many fans as he thought. But the one real fan he did have would have a profound impact on his life.
Miller knew talent when he saw it, and he wanted what was going to be the future core of the Id development team to work for him. Miller gave Romero and his team a $2,000 check, and they gave him a paragraph containing a game idea that would become the first of the Commander Keen trilogy. At this point, John Romero, John Carmack, and Adrian Carmack quit their jobs at Softdisk and formed Id Software with Apogee acting as its distributor. After a brief time in Madison, Wis., the Id team moved to its current headquarters in Mesquite, Texas.
It is in this corner of suburban Dallas that Id Software has really come into its own. Joining the founding members of lead programmer John Carmack, project leader John Romero, and graphic artist Adrian Carmack, were fellow Softdisk alums chief operations officer Jay Wilbur, creative director Tom Hall, and printed graphic artist Kevin Cloud. They formed the primary development team for Wolfenstein and Spear of Destiny, and, on completion of those two projects, reaped the rewards.
The Id Domain
Id's main working environment is a series of PCs networked together, some of which run DOS. However, when it comes to programming, NeXTStep is the team's weapon of choice. John Carmack has never regretted trudging through the snow in Madison to buy a NeXT cube. The level editor that Romero made for Doom took five human-months to make, but would have taken much longer on any other operating system.
The Super Nintendo Entertainment System (SNES) version of Wolfenstein was developed mostly on the NeXT machine, using an Apple IIGS to compile and retarget the ANSI C code. For future SNES development, Id had planned to retarget the Free Software Foundation Assembler and GNU C compiler to generate 65816 code on the NeXT machine, using a ROM emulator card to upload the code compiled in NeXTStep 486 directly to the Nintendo SNES.
Figure 1 shows DoomED, a good example of what Id can do in NeXTStep. It has the functionality of a simple CAD program and allows level designers to concentrate on level design instead of programming. From DoomED, the level designer can place monsters and objects (the different colored blocks on the screen), but, more importantly, can manipulate the walls, ceilings, and floors of the game environment. The editor allows bitmap combination from a group created by the graphic artists, so the level editor can improvise without having to draw new bitmaps.
Although it has often been theorized that Id uses a lot of assembly language in its development, the main language used is ANSI C. "Assembly language is almost dead," declares Carmack. "Doom has only two assembler routines: one to vertically stretch a column and the other to horizontally texture-map a row. Everything else is in C."
If all of Doom was written in assembler and the programmer could manage the overhead correctly, Carmack theorizes it would only make the game 15% faster. And, although the main raycasting trace in Wolfenstein was written in assembly language, Carmack says he could write Wolfenstein faster in C because of today's better algorithm technology.
Writing in ANSI C eases the strain of porting to other operating systems and recompiling the code on DOS, and NeXTStep helps clean out bugs during the development process. Carmack feels he could get Doom up and running in a window on a Macintosh over a weekend, but Id won't write the port itself. Id is willing to work with advocates of various operating systems, and talk of Macintosh, OS/2, and UNIX versions of Doom were discussed as possibilities.
The Core of Id
The two people at the core of the Id development team are the biggest fans of Id games and their harshest critics. Lead programmer John Carmack is clearly the main reason behind the technical superiority of Id's games. Talking to him about the games he's worked on is almost anticlimactic because he always emphasizes how much better he could make them today. When the contractor Id hired to do the network drivers for Doom didn't come through, Carmack matter-of-factly wrote a network driver and had it up and running the next day.
In contrast to Carmack's eternal pessimism regarding his past creations, project specialist John R
@Ahmad Khan as far as I know it still exists, but I have never been to Singapore, I got friends from there. ANd there is a website:http://www.westwoodsec.moe.edu.sg/# What has happened?
@Julia: still haven't told me the new name for the school, you know alumni as friends there so you should know.
@ Maurice Burgmans still don`t forget we are dealing with a young team from Ukraine, the team spending their own savings
нимагу я тут ниче панять, завтра брата попрашу, если я правильна понял то тут сталкер разрабы, эта крута, респект и уважуха! пайду спать а то утро уже
Beware! this Troll!
PLEASE DO NOT FEED THE TROLLS!!!!!.
Juils: there's no school with that name anymore, tell me the new school's name in its place
@ Ahmad Khan trying to prove smth you could have found it and show me, but still you can not) how is life in WestWood Secondary School?) I have some alumni as friends)
Absolutely untrue. The great majority of AAA games demonstrate a playable mission that is played by the press and is posted by them all over the net. On top of that, you are not using conventional marketing procedures you have chosen an alternative route: kickstarter. Your customers are here on kickstarter and this is where you have to show what you have as a game developer.
Not claim all your standard procedures forbid you from showing anything while such content shows up way before release in any kind of game.
@ Ronald Clark https://www.youtube.com/watch…
не понял - это марковка?
All People who want comment here and cant, we made Seperate Chat Room:
@ Julia Kravec
"So u wants from this company to write out the table with "5$ we will spend on this thing, 100$ - on that one" from the claimed 50 000&" That's a straw man argument. No-one has asked for a budget breakdown down to the $5. So far we have a $50,000 goal and some pooled savings and that's it. They refuse to give us a total. And they refuse to tell us how the money will pay for a game that will cost millions.
@Juila: don't remember,been over a year, i won't hold your hand, not my job.
Documents Show How Russia’s Troll Army Hit America The adventures of Russian agents like The Ghost of Marius the Giraffe, Gay Turtle, and Ass — exposed for the first time. posted on June 2, 2014, at 10:48 a.m. Max Seddon BuzzFeed Staff Justine Zwiebel / BuzzFeed Russia’s campaign to shape international opinion around its invasion of Ukraine has extended to recruiting and training a new cadre of online trolls that have been deployed to spread the Kremlin’s message on the comments section of top American websites. Plans attached to emails leaked by a mysterious Russian hacker collective show IT managers reporting on a new ideological front against the West in the comments sections of Fox News, Huffington Post, The Blaze, Politico, and WorldNetDaily. The bizarre hive of social media activity appears to be part of a two-pronged Kremlin campaign to claim control over the internet, launching a million-dollar army of trolls to mold American public opinion as it cracks down on internet freedom at home. “Foreign media are currently actively forming a negative image of the Russian Federation in the eyes of the global community,” one of the project’s team members, Svetlana Boiko, wrote in a strategy document. “Additionally, the discussions formed by comments to those articles are also negative in tone. “Like any brand formed by popular opinion, Russia has its supporters (‘brand advocates’) and its opponents. The main problem is that in the foreign internet community, the ratio of supporters and opponents of Russia is about 20/80 respectively.” The documents show instructions provided to the commenters that detail the workload expected of them. On an average working day, the Russians are to post on news articles 50 times. Each blogger is to maintain six Facebook accounts publishing at least three posts a day and discussing the news in groups at least twice a day. By the end of the first month, they are expected to have won 500 subscribers and get at least five posts on each item a day. On Twitter, the bloggers are expected to manage 10 accounts with up to 2,000 followers and tweet 50 times a day. They are to post messages along themes called “American Dream” and “I Love Russia.” The archetypes for the accounts are called Handkerchief, Gay Turtle, The Ghost of Marius the Giraffe, Left Breast, Black Breast, and Ass, for reasons that are not immediately clear. According to the documents, which are attached to several hundred emails sent to the project’s leader, Igor Osadchy, the effort was launched in April and is led by a firm called the Internet Research Agency. It’s based in a Saint Petersburg suburb, and the documents say it employs hundreds of people across Russia who promote Putin in comments on Russian blogs. Osadchy told BuzzFeed he had never worked for the Internet Research Agency and that the extensive documents — including apparent budgeting for his $35,000 salary — were an “unsuccessful provocation.” He declined to comment on the content of the leaks. The Kremlin declined to comment. The Internet Research Agency has not commented on the leak. Definitively proving the authenticity of the documents and their authors’ ties to the Kremlin is, by the nature of the subject, not easy. The project’s cost, scale, and awkward implementation have led many observers in Russia to doubt, however, that it could have come about in any other way. “What, you think crazy Russians all learned English en masse and went off to comment on articles?” said Leonid Bershidsky, a media executive and Bloomberg View columnist. “If it looks like Kremlin shit, smells like Kremlin shit, and tastes like Kremlin shit too — then it’s Kremlin shit.” Despite efforts to hire English teachers for the trolls, most of the comments are written in barely coherent English. “I think the whole world is realizing what will be with Ukraine, and only U.S. keep on fuck around because of their great plans are doomed to failure,” reads one post from an unnamed forum, used as an example in the leaked documents. The trolls appear to have taken pains to learn the sites’ different commenting systems. A report on initial efforts to post comments discusses the types of profanity and abuse that are allowed on some sites, but not others. “Direct offense of Americans as a race are not published (‘Your nation is a nation of complete idiots’),” the author wrote of fringe conspiracy site WorldNetDaily, “nor are vulgar reactions to the political work of Barack Obama (‘Obama did shit his pants while talking about foreign affairs, how you can feel yourself psychologically comfortable with pants full of shit?’).” Another suggested creating “up to 100” fake accounts on the Huffington Post to master the site’s complicated commenting system. WorldNetDaily told BuzzFeed it had no ability to monitor whether it had been besieged by an army of Russian trolls in recent weeks. The other outlets did not respond to BuzzFeed’s queries. Some of the leaked documents also detail what appear to be extensive efforts led by hundreds of freelance bloggers to comment on Russian-language sites. The bloggers hail from cities throughout Russia; their managers give them ratings based on the efficiency and “authenticity,” as well as the number of domains they post from. Novaya Gazeta, Russia’s only independent investigative newspaper, infiltrated its “troll farm” of commenters on Russian blogs last September. Russia’s “troll army” is just one part of a massive propaganda campaign the Kremlin has unleashed since the Ukrainian crisis exploded in February. Russian state TV endlessly asserts that Kiev’s interim government is under the thumb of “fascists” and “neo-Nazis” intent on oppressing Russian-speaking Ukrainians and exerts a mesmerizing hold on many in the country’s southeast, where the channels are popular. Ukraine has responded by banning all Russian state channels, barring entry to most Russian journalists, and treats some of the more obviously pro-rebel Russian reporters as enemy combatants. The trolling project’s finances are appropriately lavish for its considerable scale. A budget for April 2014, its first month, lists costs for 25 employees and expenses that together total over $75,000. The Internet Research Agency itself, founded last summer, now employs over 600 people and, if spending levels from December 2013 to April continue, is set to budget for over $10 million in 2014, according to the documents. Half of its budget is earmarked to be paid in cash. Two Russian media reports partly based on other selections from the documents attest that the campaign is directly orchestrated by the Kremlin. Business newspaper Vedomosti, citing sources close to Putin’s presidential administration, said last week that the campaign was directly orchestrated by the government and included expatriate Russian bloggers in Germany, India, and Thailand. Novaya Gazeta claimed this week that the campaign is run by Evgeny Prigozhin, a restaurateur who catered Putin’s re-inauguration in 2012. Prigozhin has reportedly orchestrated several other elaborate Kremlin-funded campaigns against opposition members and the independent media. Emails from the hacked trove show an accountant for the Internet Research Agency approving numerous payments with an accountant from Prigozhin’s catering holding, Concord. Several people who follow the Russian internet closely told BuzzFeed the Internet Research Energy is only one of several firms believed to be employing pro-Kremlin comment trolls. That has long been suspected based on the comments under articles about Russia on many other sites, such as Kremlin propaganda network RT’s wildly successful YouTube channel. The editor of The Guardian’s opinion page recently claimed that the site was the victim of an “orchestrated campaign.” Russian-language social networks are awash with accounts that lack the signs of real users, such as pictures, regular posting, or personal statements. These “dead souls,” as Vasily Gatov, a prominent Russian media analyst who blogs at Postjournalist, calls them, often surface to attack opposition figures or journalists who write articles critical of Putin’s government. The puerility of many of the comments recalls the pioneering trolling of now-defunct Kremlin youth group Nashi, whose leaders extensively discussed commenting on Russian opposition websites in emails leaked by hackers in 2012. Analysts say Timur Prokopenko, former head of rival pro-Putin youth group Young Guard, now runs internet projects in the presidential administration. “These docs are written in the same style and keep the same quality level,” said Alexei Sidorenko, a Poland-based Russian developer and net freedom activist. “They’re sketchy, incomplete, done really fast, have tables, copy-pastes — it’s the standard of a regular student’s work from Russian university.” The group that hacked the emails, which were shared with BuzzFeed last week and later uploaded online, is a new collective that ca
Ahmad Khan on which page?
Maurice Burgmans there is a video showing a person (designer) how he develops a creature. To show a mission before the game release means to fail the game release, it`s marketing and business. and whilst we are talking here it`s almost 38 000 obtained by WG! nive result for a young team attacked by many envious people and trolls.
you do not know!
@Julia Kravec: yup its in one of the updates, got find it yourself if you are really interested in seeing how legitimate campaign works.
тююю вы че тута? на руском ни бильши?
@ Ronald Clark thanks, I see it for sure, but I`m interested in taking chat))
хорошая ружбайка в ролике, у меня на страйке такая! пущает так, что все баятся
Ahmad Khan I saw this one, for instance https://www.kickstarter.com/projects/673576049/the-agents-a-double-edged-cards-game
you supported it. there is the tables with budget spendings there?
Beware! this Troll!
In Internet slang, a troll is a person who sows discord on the Internet by starting arguments or upsetting people, by posting inflammatory, extraneous, or off-topic messages in an online community (such as a newsgroup, forum, chat room, or blog) with the deliberate intent of provoking readers into an emotional response or of otherwise disrupting normal on-topic discussion.
Application of the term troll is subjective. Some readers may characterize a post as trolling, while others may regard the same post as a legitimate contribution to the discussion, even if controversial. Like any pejorative term, it can be used as an ad hominem attack, suggesting a negative motivation.
As noted in an OS News article titled "Why People Troll and How to Stop Them" (January 25, 2012), "The traditional definition of trolling includes intent. That is, trolls purposely disrupt forums. This definition is too narrow. Whether someone intends to disrupt a thread or not, the results are the same if they do." Others have addressed the same issue, e.g., Claire Hardaker, in her Ph.D. thesis "Trolling in asynchronous computer-mediated communication: From user discussions to academic definitions", and Dr. Phil. Popular recognition of the existence (and prevalence) of non-deliberate, "accidental trolls", has been documented widely, in sources as diverse as the Urban Dictionary, Nicole Sullivan's keynote speech at the 2012 Fluent Conference, titled "Don't Feed the Trolls" Gizmodo, online opinions on the subject written by Silicon Valley executives and comics.
Regardless of the circumstances, controversial posts may attract a particularly strong response from those unfamiliar with the robust dialogue found in some online, rather than physical, communities. Experienced participants in online forums know that the most effective way to discourage a troll is usually to ignore it, because responding tends to encourage trolls to continue disruptive posts – hence the often-seen warning: "Please do not feed the trolls".
Early incidents of trolling were considered to be the same as flaming, but this has changed with modern usage by the news media to refer to the creation of any content that targets another person. The Internet dictionary NetLingo suggests there are four grades of trolling: playtime trolling, tactical trolling, strategic trolling, and domination trolling. The relationship between trolling and flaming was observed in open-access forums in California, on a series of modem-linked computers. CommuniTree was begun in 1978 but was closed in 1982 when accessed by high school teenagers, becoming a ground for trashing and abuse. Some psychologists have suggested that flaming would be caused by deindividuation or decreased self-evaluation: the anonymity of online postings would lead to disinhibition amongst individuals Others have suggested that although flaming and trolling is often unpleasant, it may be a form of normative behavior that expresses the social identity of a certain user group According to Tom Postmes, a professor of social and organisational psychology at the universities of Exeter, England, and Groningen, The Netherlands, and the author of Individuality and the Group, who has studied online behavior for 20 years, "Trolls aspire to violence, to the level of trouble they can cause in an environment. They want it to kick off. They want to promote antipathetic emotions of disgust and outrage, which morbidly gives them a sense of pleasure."
In academic literature, the practice of trolling was first documented by Judith Donath (1999). Donath's paper outlines the ambiguity of identity in a disembodied "virtual community" such as Usenet:
In the physical world there is an inherent unity to the self, for the body provides a compelling and convenient definition of identity. The norm is: one body, one identity ... The virtual world is different. It is composed of information rather than matter.
Donath provides a concise overview of identity deception games which trade on the confusion between physical and epistemic community:
Trolling is a game about identity deception, albeit one that is played without the consent of most of the players. The troll attempts to pass as a legitimate participant, sharing the group's common interests and concerns; the newsgroups members, if they are cognizant of trolls and other identity deceptions, attempt to both distinguish real from trolling postings, and upon judging a poster a troll, make the offending poster leave the group. Their success at the former depends on how well they – and the troll – understand identity cues; their success at the latter depends on whether the troll's enjoyment is sufficiently diminished or outweighed by the costs imposed by the group.
Trolls can be costly in several ways. A troll can disrupt the discussion on a newsgroup, disseminate bad advice, and damage the feeling of trust in the newsgroup community. Furthermore, in a group that has become sensitized to trolling – where the rate of deception is high – many honestly naïve questions may be quickly rejected as trollings. This can be quite off-putting to the new user who upon venturing a first posting is immediately bombarded with angry accusations. Even if the accusation is unfounded, being branded a troll is quite damaging to one's online reputation.
Susan Herring and colleagues in "Searching for Safety Online: Managing 'Trolling' in a Feminist Forum" point out the difficulty inherent in monitoring trolling and maintaining freedom of speech in online communities: "harassment often arises in spaces known for their freedom, lack of censure, and experimental nature". Free speech may lead to tolerance of trolling behavior, complicating the members' efforts to maintain an open, yet supportive discussion area, especially for sensitive topics such as race, gender, and sexuality.
Yes i was talking about how WG could show their engine, not you. But you get my point.
Как тут фотку свою втулить? а то мне брат поставил фото, у меня есть где-то на флешке хорошие фоточки
I have seen othher KS projects do better budget breakdowns, and some are pie charts, so can be done
@ Maurice Burgmans "missions you have already worked "? personally I do nothing there)))
. ¦ ¦
(?.¦? (?.¦? (?.¦??`***?
Julia: yes, because thats what other KS projects are doing,they have pie charts and bar graphs, if you ever bothered to check legitimate KS projects
Это че? те кто сталкер делал? это сталкер2?
So u wants from this company to write out the table with "5$ we will spend on this thing, 100$ - on that one" from the claimed 50 000&
Show in a video what it does.
Show it with whatever AI, inventory system and missions you have already worked out as you have sorted them out already.
ну ты зараза! и что ты вот написал?
While there are plenty of behaviour tree tutorials and guides around the internet, when exploring whether they would be right for use in Project Zomboid, I ran into the same problem again and again. Many of the guides I read focused very heavily on the actual code implementations of behaviour trees, or focused purely on the flow of generic contextless nodes without any real applicable examples, with diagrams like so:
While they were invaluable in helping me understand the core principles of Behaviour Trees, I found myself in a situation where despite knowing how a behaviour tree operated, I didn't really have any real-world context as to what sort of nodes I should be creating for the game, or what an actual fully developed behaviour tree would look like.
I've spent a ton of time experimenting (for the record since Project Zomboid is in Java I’m using the fantastic JBT - Java Behavior Trees (http://sourceforge.net/projects/jbt/) so didn't have to concern myself with the actual code implementation. However there are plenty of tutorials out there focusing on this, as well as implementations in many commonly used game engines.
It's possible some of the more specific decorator node types I detail here are actually native to JBT instead of general behaviour tree concepts, but I've found them to be integral to the way PZ behaviour trees work, so they are worth considering for implementation if your particular behaviour tree does not support them.
I’m not professing to be an expert on the subject, however over the development of the Project Zomboid NPCs I’ve found the results I’ve had to be pretty solid, so thought I’d bash out a few things that if I’d known would have made my first attempts go a lot more smoothly, or at least opened my eyes to what I could accomplish with behaviour trees. I’m not going to dig into the implementation but just give a few abstracted examples that were used in Project Zomboid.
So the clue is in the name. Unlike a Finite State Machine, or other systems used for AI programming, a behaviour tree is a tree of hierarchical nodes that control the flow of decision making of an AI entity. At the extents of the tree, the leaves, are the actual commands that control the AI entity, and forming the branches are various types of utility nodes that control the AI’s walk down the trees to reach the sequences of commands best suited to the situation.
The trees can be extremely deep, with nodes calling sub-trees which perform particular functions, allowing for the developer to create libraries of behaviours that can be chained together to provide very convincing AI behaviour. Development is highly iterable, where you can start by forming a basic behaviour, then create new branches to deal with alternate methods of achieving goals, with branches ordered by their desirability, allowing for the AI to have fallback tactics should a particular behaviour fail. This is where they really shine.
Data Driven vs Code Driven
This distinction has little relevance to this guide, however it should be noted that there are many different possible implementations of behaviour trees. A main distinction is whether the trees are defined externally to the codebase, perhaps in XML or a proprietary format and manipulated with an external editor, or whether the structure of the trees is defined directly in code via nested class instances.
JBT uses a strange hybrid of these two, where an editor is provided to allow you to visually construct your behaviour tree, however an exporter command line tool actually generates java code to represent the behaviour trees in the code-base.
Whatever the implementation, the leaf nodes, the nodes that actually do the game specific business and control your character or check the character’s situation or surroundings, are something you need to define yourself in code. Be that in the native language or using a scripting language such as Lua or Python. These can then be leveraged by your trees to provide complex behaviours. It is quite how expressive these nodes can be, sometimes operating more as a standard library to manipulate data within the tree itself, than just simply character commands, that really make behaviour trees exciting to me.
A core aspect of Behavior Trees is that unlike a method within your codebase, a particular node or branch in the tree may take many ticks of the game to complete. In the basic implementation of behaviour trees, the system will traverse down from the root of the tree every single frame, testing each node down the tree to see which is active, rechecking any nodes along the way, until it reaches the currently active node to tick it again.
This isn’t a very efficient way to do things, especially when the behaviour tree gets deeper as its developed and expanded during development. I’d say its a must that any behaviour tree you implement should store any currently processing nodes so they can be ticked directly within the behaviour tree engine rather than per tick traversal of the entire tree. Thankfully JBT fits into this category.
A behaviour tree is made up of several types of nodes, however some core functionality is common to any type of node in a behaviour tree. This is that they can return one of three statuses. (Depending on the implementation of the behaviour tree, there may be more than three return statuses, however I've yet to use one of these in practice and they are not pertinent to any introduction to the subject) The three common statuses are as follows:
The first two, as their names suggest, inform their parent that their operation was a success or a failure. The third means that success or failure is not yet determined, and the node is still running. The node will be ticked again next time the tree is ticked, at which point it will again have the opportunity to succeed, fail or continue running.
This functionality is key to the power of behaviour trees, since it allows a node's processing to persist for many ticks of the game. For example a Walk node would offer up the Running status during the time it attempts to calculate a path, as well as the time it takes the character to walk to the specified location. If the pathfinding failed for whatever reason, or some other complication arisen during the walk to stop the character reaching the target location, then the node returns failure to the parent. If at any point the character's current location equals the target location, then it returns success indicating the Walk command executed successfully.
This means that this node in isolation has a cast iron contract defined for success and failure, and any tree utilizing this node can be assured of the result it received from this node. These statuses then propagate and define the flow of the tree, to provide a sequence of events and different execution paths down the tree to make sure the AI behaves as desired.
With this shared functionality in common, there are three main archetypes of behaviour tree node:
A composite node is a node that can have one or more children. They will process one or more of these children in either a first to last sequence or random order depending on the particular composite node in question, and at some stage will consider their processing complete and pass either success or failure to their parent, often determined by the success or failure of the child nodes. During the time they are processing children, they will continue to return Running to the parent.
The most commonly used composite node is the Sequence, which simply runs each child in sequence, returning failure at the point any of the children fail, and returning success if every child returned a successful status.
A decorator node, like a composite node, can have a child node. Unlike a composite node, they can specifically only have a single child. Their function is either to transform the result they receive from their child node's status, to terminate the child, or repeat processing of the child, depending on the type of decorator node.
A commonly used example of a decorator is the Inverter, which will simply invert the result of the child. A child fails and it will return success to its parent, or a child succeeds and it will return failure to the parent.
These are the lowest level node type, and are incapable of having any children.
Leafs are however the most powerful of node types, as these will be defined and implemented by your game to do the game specific or character specific tests or actions required to make your tree actually do useful stuff.
An example of this, as used above, would be Walk. A Walk leaf node would make a character walk to a specific point on the map, and return success or failure depending on the result.
Since you can define what leaf nodes are yourself (often with very minima
in which way can they show their engine, if I understood u right? How can they?
Ты че? секса хочешь? нашел где
i'm sexy! yes!