WordPress plugin: insert link to latest post (in category) on your menu

Instructions:

  1. Copy/paste this into your functions.php (TODO: convert it to a standalone php file, and make it into a plygin you can activte/deactivate)
  2. Create a new menu item of type “custom URL”
  3. Make your URL “http://#latestpost:category_name”
    • where “category_name” is the name of the category whose latest post you want to link to
  4. Make the name whatver you want to appear on the menu
  5. Profit!

Based on an idea (with some upgrading + bugfixes for latest WordPress in 2016) from http://www.viper007bond.com/2011/09/20/code-snippet-add-a-link-to-latest-post-to-wordpress-nav-menu/

[php]
/** Adam: add support for putting ‘latest post in category X’ to menu: */
// Front end only, don’t hack on the settings page
if ( ! is_admin() ) {
// Hook in early to modify the menu
// This is before the CSS "selected" classes are calculated
add_filter( ‘wp_get_nav_menu_items’, ‘replace_placeholder_nav_menu_item_with_latest_post’, 10, 3 );
}

// Replaces a custom URL placeholder with the URL to the latest post
function replace_placeholder_nav_menu_item_with_latest_post( $items, $menu, $args ) {

$key = ‘http://#latestpost:’;

// Loop through the menu items looking for placeholder(s)
foreach ( $items as $item ) {

// Is this the placeholder we’re looking for?
if ( 0 === strpos( $item->url, $key ) )
{

$catname = substr( $item->url, strlen($key) );
// Get the latest post
$latestpost = get_posts( array(
‘posts_per_page’ => 1,
‘category_name’ => $catname
) );

if ( empty( $latestpost ) )
continue;

// Replace the placeholder with the real URL
$item->url = get_permalink( $latestpost[0]->ID );
}
}

// Return the modified (or maybe unmodified) menu items array
return $items;
}
[/php]

Which languages need Entity Systems libraries right now?

A few months ago I ran a survey to find out which programming-languages people were using with Entity Systems:

https://docs.google.com/forms/d/18JF6uCHI0nZ1-Yel76uZzL1UfFMI21QvDlcnXSGXSHo/viewform

I’m about to publish a Patreon article on Entity Systems (here if you want to support me), but I wanted to put something up on my blog at the same time, so here’s a quick look at the stats.
Continue reading “Which languages need Entity Systems libraries right now?”

LFG: I’m looking for CTO/TechDirector/Head of Mobile/Consulting roles in CA, TX, London, and Asia

TL;DR: experienced CEO/CTO/TechDirector with long background in programming, sales, and business management (Corporate, iPhone/Android, Games, Education) looking for strategic roles in USA, UK, and Asia.

After a year-out to do a post-graduate degree in Education, I’m looking for something new and exciting to do next. My primary goal is to boost a company or team rapidly and show significant outcomes – increased revenue or other KPI’s – either through Consulting or full/part-time senior leadership.
Continue reading “LFG: I’m looking for CTO/TechDirector/Head of Mobile/Consulting roles in CA, TX, London, and Asia”

New #unity3d feature: Virtual Scenes

Unity3D has a great core architecture – it’s easy to understand and use. However, it has some significant flaws.

One of the recurring problems I run into is that Unity requirs you to have precisely one “Scene” at any one time, but often you need to have multiple scenes at the same time. Problem? Yes, lots…

Unity 5 has some hacks to make it “sort-of possible” to have multiple scenes at once in-Editor.

Note: these were mentioned by Unity corp in August 2014, but aren’t available to most users yet

But they (appear to be) hacks: they help for a fraction of the use-cases. That’s fine: Unity has 10 years of software written on the assumption there is only one “Scene”; that’s an enormous amount of code to change! But can we do something about this?

TL;DR: I’ll put this on the Asset Store

If you just want a working solution, here’s the Unity Asset store page / support page, new versions will appear here first.

I’m using it myself on my own projects, and will do some beta testing with other people’s games. If it works well enough, it’ll go on Asset Store. I suggest reading this full post anyway – it’s an example of how to creatively solve small issues like this in Unity.

(if you’d like to beta-test this, tweet me @t_machine_org or email me (address at top of page). Unity Corp only let me have 12 beta-testers, so you’ll need to give me some info about what you’ll use it for, how soon, how much feedback you’ll give me, etc! Sorry :( )

Continue reading “New #unity3d feature: Virtual Scenes”

Writing a #unity3d mini-game … to help you design a AAA game

One of my hobby projects is a testament to the Ultima and Elder Scrolls games – a massive open-world, where everything you do impacts the world around you. This has long been promised by commercial games – and it sucks from a gameplay perspective; it’s just not fun. But a very old ASCII-graphics game, Omega, showed a couple of ways of doing it that delivered on that promise while still being “fun” – very fun! That’s what I’m working towards.

It’s a test-bed for the high-performance Entity System I’m writing for Unity (more info here). I’m aiming for “gameplay considerably richer than Skyrim” with “graphics about the level of Oblivion”. To be clear: Oblivion was released almost 10 years ago! To reproduce those graphics today is fairly easy.

Challenge: Believable Cities that evolve over time

One of the things I have yet to see in any FPS RPG is believable cities, and more: cities that actually evolve. The nearest I’ve seen is the beautiful “large towns” of the Assassin’s Creed series (they represent cities, but the distances are way too small).

That doesn’t cover the “evolve” part though – even the AC cities are 100% static and unchanging. Hand-crafted, and because they cannot change (technical design choice) the player is incapable of altering them. You can’t burn down blocks, or build a new bridge. You can’t buy two houses and knock them together.

Hey, RPG industry, you can do a lot better!

This is one of the main new gameplay elements in my design. If all I managed was to take an off-the-shelf-RPG mod and add living, growing cities … I’d probably be content. What does this mean, though?
Continue reading “Writing a #unity3d mini-game … to help you design a AAA game”

#unity3d missing docs: EditorWindow lifecycle

If you do any non-trivial customization of Unity Editor, you’ll almost certainly extend EditorWindow. But Unity (to date) refuses to tell anyone how to do this legally, or what the contracts you’re being held to are. Without that, many plugins on the Unity Asset Store are wrong and buggy, and sooner or later accidentally cause problems for users.

Their fault? Partly, but I don’t blame them too much – rather: Unity’s fault for failing to document (and failing to test assets before approving them!).

For those of you who aren’t happy shipping crappy, broken, buggy plugins (And charging for them), here’s a guide / reference for the lifecycle of EditorWindow. Extra info, explanations, and gotchas welcome!

Docs-UnityEditorWindow

I’m working on my own Entity System for Unity; want to follow it?

…Sign up here to be kept up-to-date on the project’s upcoming Kickstarter / Patreon / whatever-it-ends-up-being (if you’re already signed up, it won’t add you again)

[smlsubform emailtxt=”” showname=” mailinglist=”ecs-kickstarter”]

Entity ID’s: how big, using UUIDs or not, why, etc?

This has come up a few times, and I ended up replying on Twitter:

But that’s a crappy way to find things later, so I made a quick-and-dirty infographic with a few key points:

Docs-entityID

I’m working on my own Entity System; want to follow it?

Support me on Patreon, writing about Entity Systems and sharing tech demos and code examples

2015 talk: Progress on An Entity System for #Unity3d

Slides from my talk last night at Unity Brighton.

Three parts:

  1. First: introduction / overview of Entity Systems, and why you care (as a “person who makes games”)
  2. Second: Progress so far: screenshots of the Unity Editor with explanation of the new features I’ve added
  3. Third: Challenges and solutions I’ve encountered so far

Aliqua-progress-2015-BUUG-v3

WordPress, HTML, the web etc – don’t support “presentations” yet. No, I’m not creating a fake Slideshare account just so you can wait ages for a non-bookmarkable slide viewer to (slowly) load. Until then … we have PDF. Enjoy!

#Unity3d’s missing core: No runtime objects

Here’s a game:

  • Player
    • Inventory
      • Gun 1
        • AmmoHolder
      • Gun 2
        • AmmoHolder

Some of those are 3D visual objects: Player, Gun 1, Gun 2.

Some of those are abstract concepts, or data: Inventory, AmmoHolder.

(in a Diablo clone, the Inventory might be a visual object, but only when you bring up the popup-window to display it. By contrast, in a simple FPS, your inventory may not be displayed at all – no need for it!)

Unity cannot handle this situation.

What you need

Classes:

  • PlayerClass
  • InventoryClass
  • GunClass
  • AmmoHolderClass

In Unity, you have to make “everything” extend MonoBehaviour. That’s fine for PlayerClass and GunClass: you make a dummy GameObject for each, place it into the scene, and attach the class as a Component.

But that’s impossible for InventoryClass and AmmoHolderClass: if you make them into MonoBehaviours, Unity prevents you from using them as standard classes any more:

  1. Cannot instantiate them
  2. Cannot use Garbage Collection

…because they have no GameObject to be attached to – they don’t exist! They are abstractions only.

This is core to programming: we use abstractions all the time. Without them, coding would be horrendously inefficient both for the programmer and (to a lesser extent) for the computer.

What Unity offers

You have three alternatives here:

  1. Create fake GameObjects anyway. Put them “somewhere”. Work really hard to make sure they never accidentally appear in front of the camera (!), or interact with the scene due to physics (!), etc
  2. Use plain C# classes. This is an extremely bad idea: Unity has never supported C# classes for anything; Unity has a custom memory-management solution (called, slightly confusingly, “Serialization”) which is incompatible with plain C#. It requires every object to extend Unity.Object. You can workaround this; it requires major work and is very hard to get right.
  3. Use ScriptableObject, which appears to have been invented for this. According to many Unity developers: “this is what ScriptableObject is for”. However, that’s wrong. Very wrong.

ScriptableObject to the rescue?

So … ScriptableObject is something that extends UnityObject (fixing the problem of “plain C# classes aren’t compatible with Unity”), and you can use in a Scene, and can be referenced by MonoBehaviours, and just work, right?

Wrong.

ScriptableObject is all those things, except: it doesn’t exist in the Scene. It’s an Asset.

This is where Unity docs really screw the pooch. We know for a fact that an SO is an Asset; when we try to use it like a MonoBehaviour, several things break and stop working.

…but it also “kind of” works in-Scene. The docs have no explanation for this. What are the limits? Well, basically: no-one knows, except through trial and error. This is so core to your code that it sometimes instead means:

trial and oh-crap-that-didn’t-work-time-to-rewrite-every-damn-class

Why is Asset-hood so bad?

You already have all that – it’s called the Class – and to have an Asset too simply creates problems:

  • An Asset is a special thing in Unity. It interacts with Unity’s core systems in very different ways to a C# object. Building, runtime Loading, editing in the Editor – all are “different”.
  • You can’t create them in the Editor. (you can write your own hack/script to fix this. It’s only 10 lines of code. But … yeah. It’s a hint that this isn’t what Assets are intended for)

But .. what’s ScriptableObject for?

Unity’s official docs are rather … incoherent … on the subject. My guess is that they were written by someone who didn’t really understand ScriptableObject, and was looking at the source code thinking:

WTF is this? Um. Err. Well … it kind-of seems to sort-of do … this? Maybe?

…and worked it out from observation.

What the docs are TRYING to say is:

(gross over-simplification here to make things easy to understand): Unity’s memory-management COPIES every instance many times, and doesn’t support pointers/references.

This is a HUGE problem in game-development.

ScriptableObject is a workaround that uses diskspace to make templates out of objects, and then simulates pointers by using one shared-file on disk to hold the data for thousands of in-game objects.

This works very well, because the way we built Unity’s core architecture (3D Meshes, Textures etc) already supports that workflow: File-on-disk generates optimized in-memory-object, which is shared/batched wherever possible.

Going off on a tangent, it waffles about “ShopStore” and “Multiple Scenes” and stuff that the author clearly didn’t really understand. The obvious way of implementing what’s described in the docs is many times simpler, and works much better – you would never do it using ScriptableObject.

What the docs perhaps should have instead said was:

You can also abuse this system to make hardcoded fake in-scene objects that don’t have to be attached to a GameObject.

This will fail if you have any Procedural Content – but Unity was specifically designed never to be used in games that have procedural generation, and no-one should be doing procedural work in Unity, so that’s fine.

Wait … what? What do you mean “we all do procedural generation”? Wh … why? Why would you do such a thing? do you have any idea how slow that will be in Unity? Most of our code assumes everything is done at compile time! We can’t handle dynamic code!!!

(NB: Unity used to be really, really bad at procedural work. Way too slow. There’s really no reason not to be doing tonnes of procedural code in Unity games today – except that Unity itself still has a load of political blocks on it. It doesn’t support procedural properly in places where it could)

ScriptableObject is great, but most game-development works with procedural content. I’m not talking about complex cool stuff like Sir, you are being hunted. I’m talking about stuff like:

The set of objects in your inventory changes from moment to moment while you play the game. Because otherwise it would be a pretty boring game

When you try to use ScriptableOject here, you are abusing it. It’s not intended for that, it doesn’t work correctly with that, and it’ll make your life hard. IT’s not ScriptableObject’s fault; it’s your fault.

What does Unity need?

At a conceptual level, Unity has:

  • “Physical Runtime objects”: things that have 3D physical presence in the editro (not Physics as in “Physics Engine”, but rather: everything has a Transform)
  • “Runtime OOP Objects, dependent upon GameObject”: generated from OOP Classes (but MUST be attached to a Physical Runtime object)
  • “Compile time OOP Objects”: these are Unity Assets, and can be used for some performance and coding tricks. They are they poorly-documented ScriptableObject, and should probably have been named ScriptableAsset in the first place since they are absolutely not Objects!

What’s missing?

  • “Runtime OOP Objects, independent of GameObject: the classic “Object” from OOP.

I think … not sure, this seems obvious, but if so: why is not already the case? … I think: Unity should be saying “make your classes extend ‘Unity.Object’, and then use them. All will be fine. We’ve made it work under-the-hood; trust us, guys, it’s cool. Everything’s cool.”.

My guess is that’s some internal bug with Unity Serialization that makes this untractable. Maybe something like:

GUESS: Unity Seriailization is internally hardcoded with a fixed number of recognized classes, somewhere, that can only be added to by hardcoding new ones. Because we don’t have access to Unity’s source code, we cannot re-generate those, and the Unity Editor (for same reason) can’t do it for us.

So: our legitimate C# classes can never be fully treated as a Unity Class.

Instead, Unity has to support a fixed number of hardcoded classes (O hai! ScriptableObject, MonoBehaviour), and those have to use reflection tricks at runtime to provide (limited) support for the infinitely many user-authored clases from C#.

OK, so this is slightly more than a “guess”. They have form here: When trying to figure out some obscure Unity Serialization bugs, I found some places where Unity would load extra, hidden, information for particular Unity classes. There was nothing in memory on this, suggesting that they had hardcoded a lookup for their set of “known” Unity classes, and were getting the data that way.

…but that’s the kind of thing that’s going to be a genuine mind-f*ck to try and unravel. This makes me inclined towards it: even with the money and resource Unity has, it would be non-trivial to fix. And I’m pretty sure no-one likes the status quo.

Conclusions

We’ll just keep writing source code like it’s 1999:

  • Use C# as if it’s C
  • F*ck Garbage Collection (we can’t have it :( Sob.)
  • Manually memory-manage the scene and objects; make everything a GameObject, and manually Destroy() everything each time you replace it or it goes out of scope
  • As a bonus: the Unity Editor has much better support for Developing and Debugging games which use GameObjects than it does for any alternatives (C# Classes; ScriptableObjects)

I’m crossing my fingers that Unity version 6 will dump Serialization, and this problem will go away. Like magic, Unity will fully support C# (Dictionary’s! Objects! Garbage Collection! YAY!)

…of course, by then, I might have finally switched to Unreal. Because frankly I’ve got better things to do with my life than work in low-level programming languages!

Some thoughts on loading Scenes in #unity3d

How do you program a “level”?

This is not usually a problem in a¬†game engine, but Unity requires you to isolate each “level” as a Scene. And Unity’s Scenes have some strange design choices (bugs?) – IMHO they were designed for toy projects, not for production games.

Here’s a stream-of-consciousness on what works, what doesn’t, and how I can workaround / do it better within Unity… it’s not carefully researched, mostly it’s from memory / off the top of my head. So … it might not all be true :).

When I switch to Unreal4, I’ll be using posts like this as a baseline to compare where Unity failed, and how badly – or vice versa.

UPDATE: added some more approaches and ideas/commentary

Continue reading “Some thoughts on loading Scenes in #unity3d”

Fix #Unity3d’s broken OnMouseDown

This one has annoyed me for years: Unity’s OnMouseDown has never really worked. (NB: it works perfectly if you make a scene with a single cube; but that is not a game. It breaks completely as soon as you add multiple objects, colliders, etc to a scene)

The main reason to use a 3rd party engine is to avoid re-inventing the wheel; it’s tragic that Unity can’t even do mouse-input out of the box. Let’s fix it!

Continue reading “Fix #Unity3d’s broken OnMouseDown”

Blender tips: set your 3D lights for edit mode

When you first install Blender, DO THIS!

Menu: File > User Preferences… > System

Screen Shot 2015-03-04 at 10.02.37

When you look at objects in edit mode, they’ll look something like this:

Screen Shot 2015-03-04 at 10.02.49

Why?

Blender makes it very easy to get a face back-to-front.

Or to have two faces overlapping.

Or … any number of other topology bugs. At best, these kill performance in any game that uses them. At worst, they cause nightmares for your programmers and level architects when Weird Stuff Keeps Happening. They can even cause crashes (e.g. a surface that has strange holes, or inside-out faces … and then gets processed by collision detection).

This lighting setup tells you at a glance if your normals are correct. Which in turn tells you if you have pieces out of place, or if you have an angle between faces that’s smaller/bigger than you expected (quite common to spot a pair of faces that have a sharper angle than expected/intended).

Bonus: 3D printing

If you’re 3d printing, the mistakes that slow down or crash a Game engine … will cause 100% failure of prints (Wasted time, wasted plastic – and in some cases I’ve seen: damaged printers!).

So, yeah. Getting this wrong can cost thousands of dollars. Don’t do it; replace Blender’s defaults with something sane that works :).

Blender UX for the lose

This should be the default. But then … Blender’s team seems philosophically opposed to doing anything the easy way :).

#Unity3D plugin review: Advanced Inspector

The author of Advanced Inspector gave me a free copy over Christmas. I’d considered it many times, and always ended up choosing not to buy, and write my own fixes/workarounds instead. So I was keen to try this out on a hobby project and see how well it works in practice.

What is it?

A replacement for Unity’s built-in Inspector. This (optionally) changes the editing interface for every single Component in your Unity projects.

Why do we need it?

When you run Unity, you get the standard multi-pane IDE that is the Unity Editor. Whether you’re a programmer, a designer, or an artist, this is your main portal into Unity, and the starting point for all your work.

Anything you select in the 3D/2D scene causes an Inspector panel to appear, with all the editable data about that thing. Unity’s built-in Inspector is very basic; by modern standards of GUI/UX, it sucks. Fixing GUI is very expensive, so instead … Unity has gradually been making the Inspectors more and more customisable.

Traditionally this was very hard to do; in the last 12 months it has become much easier, and Unity has unlocked more features. To date, I’ve not been sure if the 3rd party plugins are fully using the new features.
Continue reading “#Unity3D plugin review: Advanced Inspector”

Debugging A* Pathfinding in Unity

I needed fast, efficient, … but powerful, adaptable … pathfinding for my hobby project. My minions have to fly, walk, crawl, teleport, tunnel their way across a procedural landscape. Getting to that point has been tricky, but the journey’s been interesting.

We want something that intelligently routes creatures around obstacles, and picks “shallow” routes instead of scaling cliffs (or vice versa for Giant Spiders etc). Something like this:

Screen Shot 2014-08-10 at 20.09.36

Continue reading “Debugging A* Pathfinding in Unity”

OpenGL ES 2 – Video on iPhone in 3D, and Texture-Map sources

This is a blog post I wrote 6 months ago, and my life got too busy to finish it off, finish testing the code, improving the text. So I’m publishing this now, warts and all. There are probably bugs. There are bits that I could explain better – but I don’t have time. Note that the code is ripped from apps where I ACTUALLY USED IT – so I know it does work, and works well!

In brief:

  1. Using different “sources” of textures in OpenGL, not just images!
  2. Using CALayer’s as a source — allows for video in 3D!
  3. Using “Video straight from the video decoding chip” as a source – faster video!

Continue reading “OpenGL ES 2 – Video on iPhone in 3D, and Texture-Map sources”