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  • From a 3D modeler to an iPhone app - what are best practices?

    - by bonkey
    I am quite new in 3D programming on iPhone and I would like to ask for hints about organizing a work between designers and programmers on that platform. Most of all: what kind of tools, libraries or plugins cooperate the best on both sides. Although I consider the question as looking for general best-practices advice I would like to find a solution for my current situation which I describe further, too. I've already done some research and found following libraries: SIO2 Khronos OpenGL ES 1.x SDK for PowerVR MBX Unity3D Oolong Game Engine I've checked modellers or plugins to them giving output formats readable by those tools: obj2opengl Wavefront OBJ to plain header file converter Blender with SIO2 exporter iphonewavefrontloader Cheetah3D PVRGeoPOD for 3DS / Maya Unfortunately I still have no clear vision how to combine any of that tools to get a desinger's work in an application. I look for a way of getting it in the most possible complete way: models, lights, scenes, textures, maybe some simple animations (but rather no game-like physics), but I still got nothing. And here comes my situation: I would like to find right way to present few (but quite complicated) models from a single scene. The designers mostly use 3DS Max 9, sometimes 10 (which partly prevents using PVRGeoPOD) and are rather reluctant to switch to something else but if there's no other choice I suppose it would be possible. The basic rule I've already found in some places "use Wavefront OBJ" not always works. I haven't got any acceptable results with production files, actually. The only things worked fine were some mere examples. Some of my models did imported incomplete, sometimes exporters hung or generated enormous files not really useful on an iPhone, sometimes enabling textures (with GL_TEXTURE_2D) just crashed an app. I know it might be a problem with too complicated models or my mistakes coming from inexeperience but I am not able to find any guidelines for that process to have streamlined cooperation with designers. I am even willing to write some things from scratch in pure OpenGL-ES if it's necessary, but I would like to avoid what might be avoided and get the most from the model files. The best would be the effect I saw on some SIO2 tutorials: export, build & go. But at that moment I've got only "import, wrong", "import, where are textures?", "import, that almost looks fine, export, hang" and so on... Is it really so much frustrating or I am just missed something obvious? Can anybody share his/her experience in that field and tell what kind of software uses for "making things happen"?

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  • USE case to Class Diagram - How do I?

    - by 01010011
    Hi, I would like your guidance on how to create classes and their relationships (generalization, association, aggregation and composition) accurately from my USE case diagram (please see below). I am trying to create this class diagram so I can use it to create a simple online PHP application that allows the user to register an account, login and logout, and store, search and retrieve data from a MySQL database. Are my classes correct? Or should I create more classes? And if so, what classes are missing? What relationships should I use when connecting the register, login, logout, search_database and add_to_database to the users? I'm new to design patterns and UML class diagrams but from my understanding, the association relationship relates one object with another object; the aggregation relationship is a special kind of association that allows "a part" to belong to more than one "whole" (e.g. a credit card and its PIN - the PIN class can also be used in a debit card class); and a composition relationship is a special form of aggregation that allows each part to belong to only one whole at a time. I feel like I have left out some classes or something because I just can't seem to find the relationships from my understanding of relationships. Any assistance will be really appreciated. Thanks in advance. USE CASE DIAGRAM CLASS DIAGRAM

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  • Which knowledge base/rule-based inference engine to choose for real time Runway incursion prevention

    - by Piligrim
    Hello, we are designing a project that would listen to dialog between airport controllers and pilots to prevent runway incursions (eg. one airplane is taking off while other is crossing the runway). Our professor wants us to use Jena for knowledge base (or anything else but it should be some sort of rule-based engine). Inference is not the main thing in Jena and there's not much documentation and examples of this. So we need an engine that would get messages from pilots as input and output possible risks of incursion or any other error in message protocol. It should be easy to write rules, and should be easy to provide engine with real time data. I image it something like this: A pilot sends a message that he lands on some runway, the system remembers that the runway is busy and no one should cross it If someone is given an instruction to cross this runway, the engine should fire a rule that something is wrong When the pilot sends a message that he left the runway and goes to the gate, the system clears the runway and lets other planes to use it. So is Jena, or prolog or any other rules engine suitable for this? I mean it is suitable, but do we really need to use it? I asked the prof. if we could just keep state of the runway and use some simple checks based on messages we receive and he said that it is not scalable and we need the knowledge base. Can someone give me any advise on which approach to use for this system? If you recommend k.b., then which one should we use? The project is written in java. Thank you.

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  • How to model "target day" in UML Classdiagrams

    - by Tobiask
    Hi there, I want to describe the following situation in an UML Classdiagram: A day, on which a newspaper is send to a customer. This day could be sth. like "every friday" or "every first day of a month". My idea to represent this in a UML Classdiagram: -targetDay:Integer -targetDayGrid:Enumeration targetDay would be sth. like "1" (for monday) oder "5" (for friday) or it could be "1" for the first day of the month or "10" for the 10th day of the month. targetDayGrid is an enum: weekly, monthly. So the enum sets the semantic meaning of the number in targetDay. I´m not happy with this, do you know any other solution to represent my problem? Or do you think my solution is okay?

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  • Optimize mysql table ?

    - by fabien-barbier
    Here is my actual table schema (I'm using Mysql) : Table experiment : code(int) sample_1_id sample_2_id ... until ... sample_12_id rna_1_id rna_2_id ... until ... rna_12_id experiment_start How can I optimize both part : sample_n_id and rna_n_id (all are bigint(20) and allow null=true) ? About values : we can have : ex : sample_1_id = 2 , Sample_2_id = 5 , ... Note : values can be updated. Ideas ? Thanks.

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  • Collaboration Diagrams: how to represent setting a variable's and attribute's value to a specified v

    - by devoured elysium
    Let's assume I have a class called MyClass with an attribute called MyAttribute and a method called MyMethod(). Inside that method I'd like to have a variable called MyVariable. I'd like to set the value of MyVariable to "MyVariable" and MyAttribute to "MyAttribute" inside the call to MyMethod(). How can I do this in a Collaboration Diagram? I can't find any info of this kind on the internet and the book I'm studying from (Applying UML and Patterns) is very vague in the details. Thanks

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  • Database design for credit based purchases

    - by FreshCode
    I need an elegant way to implement credit-based purchases for an online store with a small variety of products which can be purchased using virtual credit or real currency. Alternatively, products could only be priced in credits. Previous work I have implemented credit-based purchasing before using different product types (eg. Credit, Voucher or Music) with post-order processing to assign purchased credit to users in the form of real currency, which could subsequently be used to discount future orders' charge totals. This worked fairly well as a makeshift solution, but did not succeed in disconnecting the virtual currency from the real currency, which is what I'd like to do, since spending credits is psychologically easier for customers than spending real currency. Design I need guidance on designing the database correctly with support for the simultaneous bulk purchase of credits at a discount along with real currency products. Alternatively, should all products be priced in credits and only credit have a real currency value? Existing Database Design Partial Products table: ProductId Title Type UnitPrice SalePrice Partial Orders table: OrderId UserId (related to Users table, not shown) Status Value Total Partial OrderItems table (similar to CartItems table): OrderItemId OrderId (related to Orders table) ProductId (related to Products table) Quantity UnitPrice SalePrice Prospective UserCredits table: CreditId UserId (related to Users table, not shown) Value (+/- value. Summed over time to determine saldo.) Date I'm using ASP.NET MVC and LINQ-to-SQL on a SQL Server database.

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  • e-shop implementation: Status for Orders?

    - by Guillermo
    Hello Again my fellow programmers out there, I'm designing and programming from scratch a online shop. It has a Module to manage "Orders" that are recieved via the frontend. I'm needing to have a status to know whats happening with an order in s certain moment, let's say the statuses are: Pending Payment Confirmed - Awaiting shipment Shipped Cancelled My question is a simple one, but is very important to decide on the store design, and is: What would you do so store this status: Would you create a column for it in the Orders table or would you just "calculate" the status of each order depending if payments has been recieved or shipments has been made for every order? (except I suppose for a is_cancelled column) What would be the best approach to model this kind of problem? PD: I even wish in the future to have these statuses configurable buy other clientes using the same software..

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  • Suggest Cassandra data model for an existing schema

    - by Andriy Bohdan
    Hello guys! I hope there's someone who can help me suggest a suitable data model to be implemented using nosql database Apache Cassandra. More of than I need it to work under high loads and large amounts of data. Simplified I have 3 types of objects: Product Tag ProductTag Product: key - string key name - string .... - some other fields Tag: key - string key name - unique tag words ProductTag: product_key - foreign key referring to product tag_key - foreign key referring to tag rating - this is rating of tag for this product Each product may have 0 or many tags. Tag may be assigned to 1 or many products. Means relation between products and tags is many-to-many in terms of relational databases. Value of "rating" is updated "very" often. I need to be run the following queries Select objects by keys Select tags for product ordered by rating Select products by tag order by rating Update rating by product_key and tag_key The most important is to make these queries really fast on large amounts of data, considering that rating is constantly updated.

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  • problems with build params for accepts_nested_attributes_for

    - by holden
    I'm trying to add the user_id to a nested attribute that gets built by a parent controller but it doesn't seem to have the desired effect? Ie. I have a model called Place.rb which accepts_nested_attributes_for :reviews The nested attribute works fine and I build it inside the Places controller like so... @review = @place.reviews.build(:user_id => current_user.id) I was previously adding the user thru the form, but would like to do it thru the controller so that it only adds the user_id on creation, as it might get updated by someone else and i don't want the update changing the user_id... old way which works: <%= e.label :content, "Review" %><br /> <%= e.text_area :content, :rows => 20, :class => 'jquery_ckeditor' %><br /> <%= e.hidden_field :user_id, :value => current_user.id %> but thru the controller the build method with options has no effect? Any ideas? Can I not do this thru the build?

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  • Why eGet() in EMF returns Object rather than EObject?

    - by Gabriel Šcerbák
    I am working on some code using the EMF framework in Java, but it is really hard to use, e.g. I cannot implement OCL-like query API on top of EMF which would be type-safe. One of the reasons is that eGet() for a EStructuralFeature return just an Object, not EObject. So anything I would write must use much of null checking, type checking and type casting which is unsafe, not performant and cannot be generalized in a reusable way. Why doesn't EMF generate dummy implementations with EObject wrappers for arbitrary Object value? Implementing the EObject and hence the EClass interfaces even with simple throw UnsupportedOperationException is really a pain (the APIs are too big). The same holds for the eContainer() method which makes navigatinng the model upwards painful.

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  • How do you remove invalid hexadecimal characters from an XML-based data source prior to constructing

    - by Oppositional
    Is there any easy/general way to clean an XML based data source prior to using it in an XmlReader so that I can gracefully consume XML data that is non-conformant to the hexadecimal character restrictions placed on XML? Note: The solution needs to handle XML data sources that use character encodings other than UTF-8, e.g. by specifying the character encoding at the XML document declaration. Not mangling the character encoding of the source while stripping invalid hexadecimal characters has been a major sticking point. The removal of invalid hexadecimal characters should only remove hexadecimal encoded values, as you can often find href values in data that happens to contains a string that would be a string match for a hexadecimal character. Background: I need to consume an XML-based data source that conforms to a specific format (think Atom or RSS feeds), but want to be able to consume data sources that have been published which contain invalid hexadecimal characters per the XML specification. In .NET if you have a Stream that represents the XML data source, and then attempt to parse it using an XmlReader and/or XPathDocument, an exception is raised due to the inclusion of invalid hexadecimal characters in the XML data. My current attempt to resolve this issue is to parse the Stream as a string and use a regular expression to remove and/or replace the invalid hexadecimal characters, but I am looking for a more performant solution.

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  • Using NHibernate to select entities based on activity of children entities

    - by mannish
    I'm having a case of the Mondays... I need to select blog posts based on recent activity in the post's comments collection (a Post has a List<Comment> property and likewise, a Comment has a Post property, establishing the relationship. I don't want to show the same post twice, and I only need a subset of the entities, not all of the posts. First thought was to grab all posts that have comments, then order those based on the most recent comment. For this to work, I'm pretty sure I'd have to limit the comments for each Post to the first/newest Comment. Last I'd simply take the top 5 (or whatever max results number I want to pass into the method). Second thought would be to grab all of the comments, ordered by CreatedOn, and filter so there's only one Comment per Post. Then return those top (whatever) posts. This seems like the same as the first option, just going through the back door. I've got an ugly, two query option I've got working with some LINQ on the side for filtering, but I know there's a more elegant way to do it in using the NHibernate API. Hoping to see some good ideas here.

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  • Range-based `for` statement definition redundancy

    - by GMan - Save the Unicorns
    Looking at n3092, in §6.5.4 we find the equivalency for a range-based for loop. It then goes on to say what __begin and __end are equal to. It differentiates between arrays and other types, and I find this redundant (aka, confusing). It says for arrays types that __begin and __end are what you expect: a pointer to the first and a pointer to one-past the end. Then for other types, __begin and __end are equal to begin(__range) and end(__range), with ADL. Namespace std is associated, in order to find the std::begin and std::end defined in <iterator>, §24.6.5. However, if we look at the definition of std::begin and std::end, they are both defined for arrays as well as container types. And the array versions do exactly the same as above: pointer to the first, pointer to one-past the end. Why is there a need to differentiate arrays from other types, when the definition given for other types would work just as well, finding std::begin and std::end? Some abridged quotes for convenience: §24.6.5 The range-based for statement — if _RangeT is an array type, begin-expr and end-expr are __range and __range + __bound, respectively, where __bound is the array bound. If _RangeT is an array of unknown size or an array of incomplete type, the program is ill-formed. — otherwise, begin-expr and end-expr are begin(_range) and end(_range), respectively, where begin and end are looked up with argument-dependent lookup (3.4.2). For the purposes of this name lookup, namespace std is an associated namespace. and §24.6.5 range access template T* begin(T (&array)[N]); Returns: array. template T* end(T (&array)[N]); Returns: array + N.

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  • Generate UML from Flex Projects

    - by TERACytE
    Are there any good tools to generate UML class diagrams using the source code from a Flex Builder project? I have been trying IntelliJ but for some reason it generates the inherited class structure from the SDK and not everything below my main app.

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  • Web-based game in Python + Django and client browser polling

    - by ty
    I am creating a text-based game that implements a basic model in which multiple (10+) players interact with data and one moderator watches them and sets certain environmental statistics that affect gameplay. Recently I have begun to familiarize myself with Django. It seems to me that it would be an excellent tool for creating a game quickly, particularly because the nature of my game depends largely on sets of data (which lends itself quite well to a database). I am wondering how to "push" changes made by the game moderator to the players (for example, the moderator can decide to display an image to all players). The game is turn-based, not real-time, but certain messages need to be pushed out in roughly real-time. My thoughts: I could have each player's browser poll a status periodically (say, every 30 seconds) to see if there is a message from a moderator. But this forces a lag and means different players might receive it at different times. And reducing this interval to <10 seems like a bad idea for the server. Is there a better way to inform clients of changes? Would you suggest something other than using a web framework like Django? Thanks!

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  • UML Class Relationships

    - by 01010011
    Hi, I would like to confirm whether I am on the right track when identifying common UML class relationships. For example, is the relationship between: 1 a stackoverflow member and his/her stackoverflow user account categorized as a composition relationship or an aggregation relationship? At first I thought it was an association because this member "has a" account. However on second thought, I am thinking its composition because each "part" (user account) belongs to only one whole (user) at a time, meaning for as long as I am logged into stackoverflow, I have to use this one and only account until I log off. If I log back onto stackoverflow with a different account then its composition again. Do you agree? 2 a database and a person's user account an aggregation relationship? I think so because 1 database (the whole) can store 0...* number of user accounts (the parts) but another database can store the same user accounts. Finally, can anyone recommend a website that specializes in designing code using UML? Thanks in advance

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  • Modelling class relations

    - by phenevo
    Hi, I have a few classes: Article ------- Content ID Magazine -------- Name Code And 3 tables in database: Articles Magazines ArticlesInMagazines (two fields: IDArticle and CodeMagazine) In my app, I've got a module to manage Articles, and a datagridview to relate their associated magazines DataGridView has twofields: MagazineCode IsPublished (indicates articles which have been published in this magazine). The same article can be in many magazines (1:n) How would you implement on model ? Article have to has a field : List ?? I am concerned because Magazine associates Articles

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  • Modifying a model and texture mid-game code

    - by MicroPirate
    Just have a question for anyone out there who knows some sort of game engine pretty well. What I am trying to implement is some sort of script or code that will allow me to make a custom game character and textures mid-game. A few examples would be along the lines of changing facial expressions and body part positions in the game SecondLife. I don't really need a particular language, feel free to use your favorite, I'm just really looking for an example on how to go about this. Also I was wondering if there is anyway to combine textures for optimization; for example if i wanted to add a tattoo to a character midgame, is there any code that could combine his body texture and the tattoo texture into one texture to use (this way I can simply just render one texture per body.) Any tips would be appreciated, sorry if the question is a wee bit to vauge.

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  • Constraint Satisfaction Problem

    - by Carl Smotricz
    I'm struggling my way through Artificial Intelligence: A Modern Approach in order to alleviate my natural stupidity. In trying to solve some of the exercises, I've come up against the "Who Owns the Zebra" problem, Exercise 5.13 in Chapter 5. This has been a topic here on SO but the responses mostly addressed the question "how would you solve this if you had a free choice of problem solving software available?" I accept that Prolog is a very appropriate programming language for this kind of problem, and there are some fine packages available, e.g. in Python as shown by the top-ranked answer and also standalone. Alas, none of this is helping me "tough it out" in a way as outlined by the book. The book appears to suggest building a set of dual or perhaps global constraints, and then implementing some of the algorithms mentioned to find a solution. I'm having a lot of trouble coming up with a set of constraints suitable for modelling the problem. I'm studying this on my own so I don't have access to a professor or TA to get me over the hump - this is where I'm asking for your help. I see little similarity to the examples in the chapter. I was eager to build dual constraints and started out by creating (the logical equivalent of) 25 variables: nationality1, nationality2, nationality3, ... nationality5, pet1, pet2, pet3, ... pet5, drink1 ... drink5 and so on, where the number was indicative of the house's position. This is fine for building the unary constraints, e.g. The Norwegian lives in the first house: nationality1 = { :norway }. But most of the constraints are a combination of two such variables through a common house number, e.g. The Swede has a dog: nationality[n] = { :sweden } AND pet[n] = { :dog } where n can range from 1 to 5, obviously. Or stated another way: nationality1 = { :sweden } AND pet1 = { :dog } XOR nationality2 = { :sweden } AND pet2 = { :dog } XOR nationality3 = { :sweden } AND pet3 = { :dog } XOR nationality4 = { :sweden } AND pet4 = { :dog } XOR nationality5 = { :sweden } AND pet5 = { :dog } ...which has a decidedly different feel to it than the "list of tuples" advocated by the book: ( X1, X2, X3 = { val1, val2, val3 }, { val4, val5, val6 }, ... ) I'm not looking for a solution per se; I'm looking for a start on how to model this problem in a way that's compatible with the book's approach. Any help appreciated.

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