Everyday Flash

The conference season is upon us!

Following my last year short presentation at Flash On The Beach and at the Warsaw Flash Camp, this year I will continue my adventure with public speaking. In the next months I will be having my sessions at 3 highly interesting events.

1. FITC Amsterdam, February 22nd-23rd

FITC Amsterdam is only a few weeks away. I’ve been to FITC last year and I really enjoyed the conference (and the parties too). I am thrilled to be back this year as a speaker. If you want to catch my session it’s on Monday (Feb 22nd) at 12:30. If you are interested in Unity and in 3D in general you should definitely attend! For more information, here’s a detailed session description. I hope to see you there!

FITC it’s of course much more than my presentation. There are 2 days packed with interesting sessions, so be sure to checkout the schedule to see what’s interesting for you. There is also a party every evening – a great opportunity to do some networking and to have a few beers and some other stuff (remember, we’re in Amsterdam!). So grab your tickets before they’re all gone!

2. London LFPUG Meeting, March 25th

If you can’t attend FITC and you miss my session in Amsterdam, don’t panic! You can catch me again next month in London. On March 25th I will speak at the next in the series of LFPUG meetings.

It will be a evening packed with realtime 3D, as I will be speaking together with Rob Bateman from the Away3D team. Here’s some detailed info about the event. The event is free, all you need to do is register, so if you are in London don’t miss it!

3. FITC Toronto, April 25th-27th

Finally in April I’ll be making the move over the Atlantic all the way to Canada for FITC Toronto, where I will also be talking about Unity. There is no schedule yet, but it’s should be coming soon. However, the tickets are already on sale. If you hurry you might even get a early bird price!

This is very exciting for me for several reasons. First, it’s a major conference with 3 days of sessions, workshops and even a recruiting event. It’s not to be missed not only if you live in Toronto, but for anyone in the region. And I’ve heard people come for FITC from all over Canada and US.

Second of all it’s my first time I will attend a conference in North America. I looking forward to meet a lot of people whom so far I knew only from blogs and twitter. So if you are around don’t hesitate to get in touch!

Finally, it will be my first visit to Toronto and I heard a lot of good stuff about the city. We also plan a short family vacation afterwards to visit Montreal and Quebec.

Next?

I’m currently entirely focused on those upcoming events, preparing all the materials and the presentation. However, I hope for more opportunities in the future. If you happen to organize a Flash and/or Unity event and you are looking for speakers be sure to let me know!

I don’t have any further plans at this moment, except that I will also attend OFFF in Paris in June (as guest, not as speaker).

Photo credits [1] [2] [3]

I am proud to announce my latest project. It’s a 3D racing game done in Flash with Away3D. I worked on this project together with Calisto Labs and our client was Snowball Media. My task was to create the 3D game part. It was great fun to work on this project. The team at Calisto Labs did a awesome job and everything went smoothly!

The project required to use my Actionscript and 3D modeling skills together on a scale like I never did before. I spent a lot of time with Blender and Unity in the last months, and without this experience I feel the project would be beyond my abilities. Also, having a direct comparison between Flash and Unity allowed be to see things in a larger perspective.

Flash vs. Unity… again

I built the game with Away3D FP10. I must say that Flash 3D has gone a long way since I first started to play with it, and Away3D is a very solid engine. The 2K polygon limitation is a thing of the past, and the correct perspective projection in FP10 makes everything look so much better. The team also added some other crucial features to create 3D environments – ex. frustum clipping.

Before starting this project I was working on a Unity3D racing demo, so I managed to get quite a few ideas on how to build such a thing. However, when I moved back to Flash, I was a bit desperate because I realized how much stuff I got used to in Unity is just not there in Flash. A built-in physics engine would be the most important one.

Home-made physics and collision detection

For physics in Flash I was tempted do use JigLib at first. But soon I found out that JigLib is way too complex, creating a realistic car behavior would be very difficult and it would probably eat too many CPU cycles. I estimated that Away3D will take around 90-95% of available processing power, so there’s no space for any other complex piece of code to run in the same time. I always think that when it comes to 3D in Flash performance is quality, and there is no excuse for poor performance, even if you want something to look “realistic”. So I ended building something very very simple.

Once I got the car driving around, I needed to add some collision detection. In Unity you quickly get used to the fact that any 3d object is a collider which makes collision detection a no-brainer – just implement a listener method and get a call whenever your object collides with another one. And if you need to add realistic collision response, you just make the object a rigid body and there you go! (Ok, you may need to adjust some settings, but still it’s pretty straightforward).

In Flash it seemed like a much more complex task. I was thinking in the lines of creating a system based on the geometry of the track. I started to study curve equations just to realize I wouldn’t make it even if I had a year to complete the project! Then I remembered, that a good way to test collision with complex shapes is a bitmap.

The way it works is that it takes the car’s position and checks against a map of the track that has different colors for different areas – ex. red for the road, green for the sideways and so on… Since it samples only a few pixels per frame and all it does is check their RGB values, it’s lighting fast. Truly, Flash is the art of minimal!

Scenery

The most fun part was to create the scenery. I’ve never tried to import such a large 3D scene into Flash so I wasn’t even sure if Away3D would handle it. It turns out it did handle it pretty well. Instead of using Collada I went with Wavefront (OBJ) format for the meshes as I feel it gave me more flexibility. OBJ is a simple format which makes it a bit easier to see what’s going on while Collada is bloated and overly complex for my taste. I used Blender to model the track and the few objects that you can see around it – lampposts, houses and the tunnel.

Lightning

Lightning is very important in low poly scenes, because it adds a lot of detail and atmosphere to the scenery, without adding any polygons. Even thought the scenery is simple, I ended up having more that 60 lamps. Of course all those lights needs to be baked on the textures, there’s no way to run them in real-time. Blender has a very good texture baking tool and all this works fine for static objects. But what about objects that move, like the car?

For lightning the car, I reused the concept from collision testing. But instead of a collision map I made another one – a light map. Basically it’s a bitmap with white areas where the scenery is lit and dark ones where it’s not. By sampling a single pixel on every frame I can see if the car is passing through a lit area. Then, all I have to do is to apply a color transform on the car texture to make it brighter. Again – a minimal solution, but it works!

Now that you know all about it, go ahead and try it out!

Ringo from FlashBookmarks asked me if there were modifiers similar to AS3Dmod in Unity. I searched for something similar some time ago, but didn't find anything interesting.

However, when I was starting C# scripting, I ported two of the modifiers from AS3Dmod - Bend and Twist. So I thought to share them with everyone. Don't expect much, it's not the full library, just two classes. If I have some free time, I'll look into how to implement stacking, since for the moment you cannot apply two modifiers to the same object (the second one won't have any effect).

To play around with them grab this package and import it into Unity. Keep in mind that the modifiers work at runtime, so you won't see any effects in the editor until you run the game. If you want to animate them, just add another script that will have a reference to the modifier instance and change it's properties at each Update() call.

If you are interested in this kind of "bricolage" with 3D geometry, I recommend to take a look at the Procedural Examples project provided by Unity. You will find there some highly interesting samples like dynamic extrudes or perlin noise. It's a great starting point to explore runtime geometry transformation.

Of course, take a look into the sources of the modifiers too! You'll see how simple it is to access the geometry at runtime and do some modifications. Basically it goes like this:

Things worth notice: In Unity a vertex is just an instance of Vector3 - there isn't any special class for this, as in Flash-based 3D engines.

You can see a bit of the casting-drama I need to do (lines 1-2) to get to the object holding the actual geometry information (Mesh). That's a bit annoying in C#, with JS that code would be more readable. Anyway, it's better to make that only once, in Start() and not at every Update().

To get correct lightning effects on the materials, do not forget to call mesh.RecalculateNormals() after you've modified the positions of the vertices.

If you want to modify your mesh continuously (i.e. to animate it) it's necessary to keep the original array of vertices, because the code above overwrites the original positions. Take a look at the source code in the package to see how I did it.

That's all for now, hope you enjoy it!

There's something you'll quickly realize when you start playing with Unity. It's the fact that you won't go far without some basic knowledge of a 3D editor. I've been using Blender for my Flash 3D experiments, but I can't honestly say I knew anything about it. I was able to model some very basic shapes, and whenever I needed something more complex I'd ask someone who's more experienced or just find a free model on the Internet. With Unity it just doesn't make sense. You won't be able to understand half of the functionality if you don't have a 3D editor to work with. By the way, I'm not the only one who noticed this.

As a logical consequence, I decided to take a step back and learn Blender. I don't want to go into details on the choice of software. If you prefer Maya or Cinema4D, fine. I grew to like Blender, but I know it makes a horrible first impression. The thing about Blender is that it's free, and that's a huge advantage for beginners.

After some time of modeling, texturing and setting up lights and I started to really love that. I felt like I was taken 10 years back, at the time when I was discovering Flash, HTML, building my first "home page". I'm sure you all know the great feeling when you start to understand something new and your skills grow every day. There's nothing like it! (Ok, there are other things better than that, but let's stay within our geeky subject).

At first I wanted to get just enough skills to continue with Unity3D development. But soon I realized that this might be what I'd like to do for a living. Wait, what? Can you imagine? I'm in my thirties. I'm doing pretty well in flash development business. Is there anything more stupid that dropping all this and becoming a 3D designer? And how many years I would need to become any good at this? Or maybe it's just a matter of a couple months to master the tool and I'll be all set? But maybe I don't have what it takes to be a 3D designer. However a fundamental thing I believe in, is that there's no such thing as innate talent and all you need is enough persistence...

I've been struggling with those questions for a while, and I don't have any answers yet. In the meantime I ordered some books, found some tutorials and kept learning to keep all the options open. I still have a long way to go, but I can already see some results.

As my modeling skills grow, I feel much more confident as a 3D developer because I can understand where the assets come from, how they are built, how visual effects are achieved. Those things were like a black box to me before. Now I can even build some 3D stuff myself. It's so much worth the effort even if I'll never work as full time 3D designer.

The two Unity examples above are my first, modest 3D modeling experiences. One is a mini game. It features a scenery that I populated with a few models including my first car model. Apart from modeling the scenery elements I used that as a testing ground for many Unity features like the terrain engine, line and trail renderers, rigid body physics, car simulation, particle systems and of course scripting. The end result is a bit random, but I don't remember having that much fun for a long time!

The second is a small interior scene (really small!). I couldn't grasp how lightmaps work in Unity until one morning I woke up and I just knew (yeah, that's how it happens sometimes!). During the day, I quickly threw up this demo to test if my understanding was correct. I think it was, even though in the end the shadows came out too subtle. Anyway, I'm doing more experiments on that subject now and maybe I'll write a separate post on how to work with lightmaps in Blender & Unity.

That's it for now! I'll see where it takes me, but you should expect more 3D modeling related posts on this blog from now on. Also, I'm not giving up on coding... yet ;)

I like books. A book is always a good thing, no matter how abundant online resources are. It's always at hand, with all the information brought together in one place, not scattered across different sites or even worst, across different forum threads.

When I learned a couple of months ago that Will Goldstone was writing a book on Unity3D, I was pleasantly surprised. A bit later Packt, the publisher of the book, contacted me asking for a review.

In the meantime the book hit the shelves, and there was some buzz on Twitter, so there's a good chance you've already heard about it. If you are still wondering whether you should buy it, keep reading.

Great for beginners

The book is written in the form of one big tutorial. The author leads us through different parts of the Unity3D IDE in the course of creating a simple game. The word "simple" is key here. Before I had the chance to read the book I went through the Unity3D official tutorial which has a similar structure. It presents us with a very cool 3D artwork and a pretty complex game to build. Compared to that, what we will create with the book is pretty basic. However, in this case: simpler means better.

After completing the official tutorial I felt I merely scratched the surface, and many parts of it were too complex to follow. The book doesn't leave you with this feeling. You'll be guided in creating a game but you will do it from scratch and all the steps are explained in depth.

Scripting

I assume most readers of this blog are familiar with programming. In this case you may find the code presented in the book somewhat rudimentary. One way of making it more fun is to translate the code from JavaScript into C# on the way. I did that, and I think it's much more beneficial than just copy-pasting. At least you will read it that way.

Furthermore, Actionscript 3 programmers can find that some examples are bending the rules of strict OOP. Again, for a seasoned AS3 developer, restructuring the code in those places can be another good exercise.

The book covers obviously more than just scripting. Among other topics, I particularly enjoyed the chapters on particle systems and on 2D GUI (as you will find out, 2D GUI is the weird part of Unity)

Other ressources

An indispensable companion of the book is the Unity scripting reference. The docs are solid and in most cases you'll find what you're looking for. Not always however, and if you feel you need more info I recommend to search the forums. I am not a fan of forums overall, but I must admit that the Unity3D forum is a pretty good resource.

A remark on the Unity3D documentation

A bit off-topic, but I will take the occasion to rant about the Unity3D scripting documentation. Not about the content, but about the form.

In the Unity3D docs the list of classes is sometimes placed on the left column, sometimes in the middle. Sometimes they are listed in alphabetical order, sometimes presented in an inheritance structure. Every property and method is presented on a separate page, which is a big waste of space given the fact that most of them have max 2-3 lines of description. It leads to constant back/forward clicking when exploring the API. And it might get even worse when Unity will introduce namespace support.

It would be cool if the docs followed the good old Java standard, where the list of classes is always in the same place, always accessible and in alphabetical order. The properties and methods are listed in one big table, which is also much easier to browse.

OK, enough complaining, now back to the book...

Conclusion

If you want to get into Unity, it's probably a good idea to buy this book. You'll get yourself a decent introduction to the main aspects of the software. Remember that you won't learn any advanced stuff like stucturing code in large projects, writing custom shaders or making advanced physics simulations. The important thing is that the book explains all the basics leaving you well prepared to explore the rest. I enjoyed reading it and I learned quite a lot!

UPDATE Nov 2009 There is a better quality video posted by John from Flash On The Beach. It is available here: http://vimeo.com/7292505.

As I promised during my "3 minutes" in Brighton, I publish all the sources of my presentation. I added some comments in the code and removed the part with the slides.

Here's also the demo and a video of the mini-session. The demo is pretty rudimentary - I made so because I wanted to keep things simple during the presentation. I hope that it will be a solid base for someone who wish to create a full featured bowling game in Flash.

There were a few other implementations of a bowling game in JigLibFlash and Papervision3D. Initially, guys a Blitz Agency published a few interesting experiments with JigLibFlash, including a simple bowling simulation. Devon O. Wolfgang has written a great tutorial about building such a game on Tech Labs - be sure to check it out. I found it only after the presentation and since the tutorial explains a lot of things in details I felt like I was reinventing the wheel here. But hopefully there are still a couple of things I can add.

Thanks to the new plugin API we developped some time ago, setting up a scene with JigLib and an 3D engine has got a bit less complicated. However, tweaking the engine can be a hell. Here's a few things I found out:

1. Simulation speed

When you create the physics engine instance, the default speed of the simulation is 1. This is very slow and unrealistic. It will look much more natural if the speed is increased. Beware however - at higher speeds the collision detection system can be very inaccurate and result in objects running through each other without any collision being detected. I don't think there is a single setting that works fine in every situation, but for this case 9 worked fine for the regular speed simulation, and 2 for the "slow speed". You should always try different settings.

2. Mass

Each rigid body has a mass property. It's easy to forget about it since it has a default value and it never complains if you don't change it. However, setting the masses right is crucial for a realistic simulation. In real world object have different masses, and so they should in a simulation. This is particularly important for a bowling game, where the ball is pretty heavy and the bins are not (I guess... has anyone ever had a bowling pin in his hands?) The trick is that the masses are relative to each other, so the more different objects you have the more you need to tweak the masses to get the results right. Also remember the effect of any forces applied to an object is related to it's mass.

3. Physics material

Each rigid body has a property called material which is an instance of the MaterialProperties class. It has two properties: friction and restitution. I found out that playing with this values has a quite big impact on the simulation. Ex. setting a high value of the restitution results in the object becoming bouncy - I used this for the ball in my older ping-pong example. In the bowling demo I used lower friction on the ball to make it slide more - just as a real bowling ball does.

4. Object rotation

Once a DisplayObject is wrapped into a physics rigid body you can't rely on it's rotationX, rotationY and rotationZ propeties anymore - because they are not being set. The physics engine sets the transformation matrix directly on the DisplayObject, so if you need to check it's rotation you need to extract it from the matrix. Fortunately, there's an easy way to do this:

5. Object activity

As a result of multiple forces being applied to an object and multiple collisions sometimes the objects are left in a state where the shake a bit endlessly. This can also happen when the objects are initially positioned. Calling the RigidBody.setInactive() will fix that. And you can call more than once.

Important conclusion: tweak, tweak, tweak...

It is generally agreed that hardcoded ("magic") numbers are not a good coding practice. However in 3D animations, and especially with physics the important thing is not the beauty of the code, but the what you see at the end. If you browse the source code from this demo you will notice that I not only hardcoded a lot of values, I even left ugly lines like that:

In fact this is what I like the most in doing all those demos and experiments - the moment when code stops being just a list of instructions for the machine and becomes an art of making things look good by adding little tweaks here and there. If you tend to write very clean code and use all possible standards and conventions, from time to time make it ugly... you'll see how good it feels :)

I hope that this few tips will help you with your next JigLib project!

Last but not least, I'd like to say thanks to everyone who woke up early to see the Elevator Pitch session. It was a great experience being there and talking to you. The Brighton Dome packed with people can be intimidating and 3 minutes is not much time, so there was no place for mistakes. Fortunately, the FOTB technical crew made it all seamless. Great job guys!

Finally, I would like to give a special thanks to John Davey for inviting me to Flash On The Beach and for making this great conference happen!

Hope to see you next year!