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All posts for the month March, 2012

L-systems rendered in 3D

Posted by Shai Shapira on March 29, 2012
Posted in: 3D Graphics, Graphics. Tagged: , , , , , . 1 comment

Remember when I got all excited about L-systems and algorithmically generated plants?

That lame tree you saw in that post was definitely not the last you’ll hear of that. I’ve been making a lot of progress with my implementations since then, and got some nice results. However, it was still not something really breathtaking, so nothing was worth mentioning.

A few days ago I decided I reached the top of what 2D can get me (well, not exactly. More on that later). The really good stuff can only come when I port the code into Python, make it a blender script and start making 3D renders with it. Today I made the first step, and here’s my first L-system render:

 

The basic shape is one of many fractals based on the Koch snowflake. You might notice that the basic shape is actually 2D – I only ported the simplest possible part yet. Hopefully I’ll port the whole thing sometime in the next few days, and we’ll start seeing some really beautiful stuff.

By the way, I’m not exactly throwing 2D away. I’ve reached the end of what 2D can provide me through the book – but I think L-systems have a lot of potential outside the scope of producing good looking trees, and I hope to explore that in the future. But that will take much creativity, which is more difficult than just following a book’s instructions. For me, at least :-)

Software Testing

Posted by Shai Shapira on March 28, 2012
Posted in: My Games, Software Developement. Tagged: , . Leave a Comment

Maybe the worst thing about writing software is worrying how it will work in other people’s computers. As an indie / open source developer I don’t have much of a testing department, so what I test is pretty much what I have. If my computer has Windows 7, that’s what I test and I can only hope I wrote good enough code to avoid any platform-specific problems.

Why did I think about that now? Because it turns out that I made kind of a rookie mistake in Paddle Storm – using a backslash in file paths, which is the Windows way and probably fails on Linux. I uploaded a fix to SourceForge today, but I still can’t test it because I have no Linux machine. All I can do is be grateful to those who take the time to try and report to me when things go wrong (thank you!).

So keep that in mind in your work. And if you’re writing Java code, use File.separator.

I did get an idea today, maybe I’ll burn a Knoppix live CD so I’ll be able to test things on Linux without the trouble of installing another operating system. I’ll check that in the next few days.

The Beauty of Noise

Posted by Shai Shapira on March 25, 2012
Posted in: Graphics. Tagged: , , . Leave a Comment

I worked a little on visual noise yesterday. Noise is a little hard to appreciate when your not a programmer / artist (or maybe a little of both), but when you’ve tried a little to make good looking things on the screen, you see how important it is.

For those who don’t know what it’s good for – basically, when painting something on the screen, the initial instinct of a programmer is to choose a color and paint things with it. It’s the simplest option, both to design and to implement. The problem is, it looks bad. On a UI, it’s the backbone of the amateur looking UI that looks designed by programmers, and in in-game art looks very simple and unrealistic.

What I did until this week was use uniform noise. This is the simplest noise you can think of – just go through every pixel in the image, and add a random value to it’s red / green / blue components. This is what I did in Paddle Storm, for example. It isn’t great, but I think it does break the “computer generated” look, if you compare it with a completely smooth texture.

However, uniform noise still doesn’t look very realistic. The main reason is that real life objects, even if they have basically one color, have many imperfections, patches of dust, stains, many things that break the color and are not necessarily one pixel wide – they have darker areas and lighter areas, creating what appears to be several layers of noise – you can see big “patches” when looking from a distance, and as you get closer you see smaller and smaller patches. We want our noise to show that, but uniform noise creates a result that looks very… well, uniform.

There are several “multi-level” noise solutions these days, and the most common seems to be Perlin noise. I might try that in the future, but for now I went with a simpler algorithm that seems to produce very nice results – the midpoint displacement algorithm. For example, if I have a rectangle and want to paint it in a noisy red, here’s what I get:

You can definitely see several levels of noise here. And what does it look like in practice? Here are some isometric brick walls from a game I’m working on:

The left one has no noise. The next has uniform noise, and the others use the midpoint displacement noise, the first applies it to the saturation and the rightmost one to the brightness. I think that looks much better.

Molydeaux

Posted by Shai Shapira on March 20, 2012
Posted in: Games. Tagged: . Leave a Comment

I think I’ll pass on the “Peter Molydeaux game jam”, but I have to admit that this is hilarious. I was very surprised to find out it’s probably not a random text generator – I think I could replace pretty much every noun there with another random noun, and it would make just as much sense.

Which gives me an idea, I think I know where we could get an unlimited supply of game ideas…

The Dangers of Copying

Posted by Shai Shapira on March 19, 2012
Posted in: Math, Programming. Leave a Comment

Sometimes when you’re writing geometry-heavy code, it’s tempting to copy some stuff straight from a mathematical formula in a textboook, especially if you’re not much of a math genius and you just want something to work. But here’s how it can go unfortunately wrong:

Say you’re implementing rotation around the origin in 3D. The famous way to do it is with a rotation matrix, and everywhere you look, you’ll see these equations. Now after a little reminder about matrix multiplication, we just need to convert it to code. Simple, isn’t it?

public void rotate(double xRotation, double yRotation, double zRotation) {
    if (xRotation != 0) {
        this.y = this.y * Math.cos(xRotation) -
                     this.z * Math.sin(xRotation);
        this.z = this.y * Math.sin(xRotation) +
                     this.z * Math.cos(xRotation);
    }
    if (yRotation != 0) {
        this.x = this.x * Math.cos(yRotation) +
                     this.z * Math.sin(yRotation);
        this.z = -this.x * Math.sin(yRotation) +
                     this.z * Math.cos(yRotation);
    }
    if (zRotation != 0) {
        this.x = this.x * Math.cos(zRotation) -
                     this.y * Math.sin(zRotation);
        this.y = this.x * Math.sin(zRotation) +
                     this.y * Math.cos(zRotation);
    }
}

If you can spot why it’s broken, you’re sharper than I am. Took me about a week[1] to figure out why my rotations weren’t working.

[1] Okay, I was doing other things during that week, but it did include several failed attempts at spotting the problem.

Bunch of things

Posted by Shai Shapira on March 13, 2012
Posted in: Bunch of Things. Tagged: , , , , , . 2 comments

I want to try something new here – I often see things on the web that I think are interesting and relevant for this blog, but don’t actually deserve a post of their own, mostly because I try to keep the posts mostly about what I do, not about what other people do. However, there are some things I really think anyone interested in what I do might also be interested in. So I’ll just make a “cool stuff on the web” post once in a while.

1. A computer science / media research guy from a Danish university created something a little different with an FPS engine. It’s called “First Person Victim“, and it puts you in 1st person view of a person in a city under attack, but instead of taking a gun and fighting the enemies, you’re pretty much helpless. While it’s more an educational tool than a game, I always like people who do things with FPS engines other than “take a gun and shoot everyone”.

2. I recently downloaded the demo version of “Analogue: A Hate Story“, the first Ren’Py game I ever tried. While I’m not a fan of the visual novel genre, it made me realize that Ren’Py does have some interesting potential for gaming mechanics, and even though it’s community seems more interested in visual novels, there’s no reason not to try something else. Another thing I might try sometime.
And by the way, if you do like visual novels – this one seems pretty well written. But it costs more than I would spend on a novel.

3. Last week I filled a major hole in my gaming education, and finally played a Call of Duty game (Modern Warfare 1). My conclusion, a little surprisingly – it’s an awesome game. I agree with the many who say they (and I mean generally the leading, huge budget games, not specifically CoD) put ridiculous amount of resources in graphics, and can’t innovate anything because they need to be accessible to everyone etc. – but still, there are things that huge amount of people with a huge budget can do very well. The gameplay feels perfectly balanced, and it’s an extremely fun game. Makes me realize that I don’t actually dislike FPS games like I thought, I just dislike ultra-fast arena style FPS games.

4. I love hearing game developers talking about how they made their game. I especially love it when they are hilarious people. And do you know who’s hilarious? The guys who made Magicka.

That’s it for now.

L-systems and beautiful plants

Posted by Shai Shapira on March 8, 2012
Posted in: Graphics. Tagged: , , , . 1 comment

I came across an interesting book a few days ago – “The Algorithmic Beauty of Plants” by Przemyslaw Prusinkiewicz and Aristid Lindenmayer. If you know me even a little, you should know that I can’t resist a title like that.
And indeed, this book is awesome, and I’m already playing around with generating trees:

Apparently Prusinkiewicz is a professor at the university of Calgary who does a lot of research[1] about generating plant images, and I’m definitely going to check it out. If I can eventually generate something anywhere close to this, I’ll be a happy person.

 

[1] Seriously, his research group is called “Algorithmic Botany”. This climbs to 1st place in my (not very long yet) list of most awesome research group names.

New Domain

Posted by Shai Shapira on March 4, 2012
Posted in: Meta Blogging. Leave a Comment

A little piece of meta-blogging – this blog’s URL is now http://shaishapira.com. Old links should still work, but this is now the main address.

The blog’s name is a playful little title, but I have some big (and fun) plans for the future, and I think they will work better with a more serious sounding address. Hopefully this is just the first of many improvements to come in the near future.