Deformable terrain

No one would have believed in the first years of the twenty-first century, that this world was being simulated keenly and closely by intelligences greater than man’s and yet as mortal as his own – chipmunks.

In this project, I am trying to simulate a flexible and deformable terrain, using the outstanding physics engine Chipmunk Pro. That thing is a mighty powerful piece of software.

The basic idea is to do deformations to a bitmap image, and then scan the outline to make terrain.

The image is made with a CGBitmapContext, which allows very fast read and write access, while still having resonable render performance. The stuff we will be rendering to deform the terrain, are pretty simple anyways. First the context is filled with an image from file, represented the undistorted terrain. This image is then used by a ChipmunkContextSampler, to return he outline of the terrain for physics simulation. Various attributes can be applied  to the terrain, including smoothing. The sampler also supports sampling on blurred terrain, for real nice and smooth outputs.

Finally, a tile cache is added. It basically breaks the terrain down into smaller pieces, so that only parts of the terrain needs to be updated, when changes happen. Deformation is then made to the terrain, simply by drawing filled circles directly into the CGBitmapContext.

A demo project can be grabbed at Github.

The demo is provided as-is, but if you have questions, you can often find me in the cocos2D forum.

Ripples

For two new projects, I am working with simulating water.

Basically, the water is simulated by tesselating an image into smaller fragments, and then adjusting texture coordinates accordingly. A ripple is created with a center, and texture coordinates are then adjusted in an expanding radius around this center.

How the formula is implemented, makes the ripple simulate various materials. If the center continues to bounce undampened up and down, the material will look like a rubber sheet. The quicker the center is dampened, the lower the viscosity will seem.

A demo project for iPhone, featuring the basics of this, can be found here. If you find it useful, let me know, and I will provide updates.

https://github.com/Birkemose/rippleDemo

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This is of course very basic, so there is plenty of room for improvements.

The demo project scans the entire surface for each ripple. Only vertices inside an ongoing ripple should be scanned. This reduces the number of calculations dramatically. Next, I have added vertex lighting to make the ripples easier to see, and to emphasize multiple ripples. This makes vortexes when swirling a finger, much more distinct.

Finally, I added caustics also using vertex lighting, and subtle vertex distortion. Both caustics and distortions are dynamic, and it is easy to see how the water settles, after having been stirred.

It still needs some tweaking, and final touches will be reflection highlights, and impurities in water ( small air bubbles etc )

I give you: The moon

The moon isn’t made of green cheese. The moon is made of 12 tiles, and 12 craters.

I wanted the final missions in NighFlight to take place on the moon. I though it would add some extra atmosphere, and it would give the player 3 choices in the IAP versions. Also, some of those who played the first version, got stuck in some of the missions. With the new campaign structure, you can just switch to another campaign, and return later.

But back to the moon.

Basically, the moon is made of 12 tiles, but as the image contains shadows, I quickly realized that I couldn’t rotate the tiles ( as I did with the earth map ), and the map really didn’t look impressive. Another problem was, that in order to get the tiles to blend in, I had to remove all features near the edges, so on top of looking “constructed”, it also had a very distinct grid pattern.

Not very moonish.

So in stead of having 24 tiles ( as I have in the earth map ), I settled for 12, and converted the last 12 to “free craters”. The good thing about the craters is, that I can scale them, and place them anywhere I want. The entire map has 24 tiles on screen ( I know, really weird number and tile size ), and I then place 12-16 craters on top of that.

The craters are always placed ( with some randomness ), where tiles meet, to hide the tile-grid-pattern.

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The result is ( if I may say so ), a very convincing moon. While you of cause can recognize some of the tiles, the superimposed craters in varying sizes, makes it almost impossible to see any pattern.

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Release date is set for next week-end, after that I will go get seriously drunk.

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Oh, and here is the tilemap.

Creating your own personal score server.

As an indie developer, there are 3 options for implementing highscores, achievements, etc.

1) OpenFeint

2) GameCenter

3) CocosLive

While OpenFeint supports all your needs, my main gripe with it, is, that it is so unbelievably ugly, that I lack words. I am not prepared to spend 6 months designing a ( hopefully ) great looking game, luring the playing into a dark world of sex, money and insane violence, just to have some YDRK gamescore screen pop up. No way!

Next option would be GameCenter. While it also holds the capacity for great ugliness, it can at least be minimized, and you have much more freedom in design. On top of that, GC is supported by Apple, includes any cool feature you can ever dream of, multiplayer, you name it, and of cause it is for free. How good does it get?

Well, it doesnt work on 3G and older. What you scream in disbelief? Not even the simple highscore parts? No I tell you.

So in my book there is plenty of room for a lightweight scoring and achievement system, which works on all devices, and where you have 100% freedom of how to implement it. Such a system is CocosLive. But there are also drawbacks here.

Main problem is, that the server has been down a few times, or closed down, due to excessive data transfer, and you cant really expect somebody else to pay for your server traffic. But it still is a nice lightweight system. well tested. Easy to use, so what if I could set up my own server? For free that is.

Riq from cocos2D, has insisted that it wasn’t hard to do, but as I know absolutely nothing about servers, App Engines, and Google ( apart from surfing for … hmm … thats for another blog ), I was sceptic. On the other hand, I knew several other indies were interested in doing likewise, so I sat down and tried until it worked, documenting the steps I went through.

Note:

This is a completely über-noob take on this, and there might be faster or more clever ways of doing this. But this makes sense to me, and works.

1)

First you go http://code.google.com/appengine/downloads.html, and download the Google App Engine Launcher ( GAEL )

From the first page, select the GAEL for Python, which matches your OS, download and install it. This should be pretty straight forward, and you will be rewarded with a small notebook-looking application, with a couple of icons at the top.

2)

Next download the cocoslive source code ( I think it is )

Open the application Terminal, and enter the following line: svn checkout http://cocoslive.googlecode.com/svn/trunk/ cocoslive-read-only

This black-magic-ninja line, will for some reason download the cocoslive source code to your computer. If in doubt where it landed ( wont land in normal transfer folder ), seach for cocoslive-read-only.

3)

From GAEL, select [File]-[Add Existing Application], and browse to where the cocoslive source code landed. Don’t select the “cocoslive-read-only” folder, but a sub folder just named “cocoslive”

A line should appear, with the name cocoslive, and a path to the source code.

4)

From GAEL, select [Run], and a local copy of cocoslive will launch. Select [Browse], and it should open.

While this is cool for testing when you are offline, I don’t think it is to much use in this case. As we are setting up our own private score server, so we can just as well use that one, no-one will be bothered, even if we break it.

5)

Next step will be to transfer the cocoslive score server, to a Google server, so that the millions of people playing your application, can get access to it.

For that you need a Google account, and register for their App Engine. This is pretty straight forward, and well documented by Google, so I will not go into that here.

When you have an App Engine account, you need to log in, and create an application. It would make sense to name it after your game, but for now I will call it myapplication. When you create it, you need to check if the name is available, and in that process you will see the address, which becomes the address of your score server. In this case “http://myapplication.appspot.com”

6)

Back in GAEL, you click the [Edit] icon, and in the small texteditor that pops up, you change the first line from

application: cocoslive to application: myapplication

After that, the name on the front page of GAEL, will have changed to myapplication

7)

And now for the exiting part :)

In GAEL, click the [Deploy] icon.

If you did everything right, a lot of greek, latin and alien language will scroll down in a console, and if you are in any luck, one of the later lines will read “Deployment successful”.

If that is the case, your own private score server is now up and running, and in stead of “http://cocoslive.net”, you can access it on “http://myapplication.appspot.com”

8)

Final step will be to tell cocoslive where to look for the score server.

Open CLScoreServerPost.h and CLScoreServerRequest.h, and replace “cocoslive.net” with “myapplication.appnet.com”

And that is it.

You now has you own private score server up and running, like all the other huge companies have, and that is kewl. Just ask Sony.

It has been a while

I am getting close to finishing the free version of NightFlight.

The original 14 missions has been upped to 27, and split into 4 campaigns.

1)

Attack of the Xercs

8 missions taking place over earth

2)

Earth strikes back

8 missions taking place over their mothership

3)

Aftermath

3 mixed missions ( the free version )

4)

Battle on the moon

8 missions taking place on the moon

Apart from that, the interface has been completely revamped.

In stead of menus, everything is now controlled from inside the ESA88 spacecraft. Check out these interfaces.

And now for something completely different

To losen up my shoulders in between NightFlight work, I toyed with some of the technologies I want to implement in future games. First of all 2D physics.

For that I chose Objective Chipmunk. It integrates nicely into cocos2D, and is insanely easy to use. On top of that, it is fast.

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The mermaid demo below, simulates 400 snowflakes in a low gravity water environment. The idea was to make a fairly accurate simulation, and not just let the snowflakes magically enter at the top, and magically disappear at the bottom.

The mermaid is a small script file, with image data, and information on where the snowflakes can land, so making new scripts is very very easy.

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Runs between 20 and 30 FPS on a plain vanilla 3G.

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Lite version

Well, I cant be laying on the couch all week, so I started work on the LITE version.

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The LITE will include 5 unique missions taking place after the full game. With the LITE, I plan to release an update, implementing some of the feedback I have received, and adding some extra graphics.

I the graphics department, I added a fire / smoke / debris system, shown in the video below.

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Cheers

 

 

Release

NightFlight is now live in the store, and months of hard work is over. For now.

http://itunes.apple.com/us/app/nightflight/id418884779?mt=8

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There will be a lite version within a few weeks.

The lite version will feature the training mission, and 4 completely new missions, taking place after the original game.

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The betasection will be removed, and replaced by a NightFlight section, featuring a mission guide.

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But for now, I will just lay on the couch … staring at the ceiling …

 

Final mission intro

This is the final mission intro / calibration sequence, before the game starts. Apart from this, I added ability to recalibrate in missions, and a retry button if a mission fails.

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A lot of the ideas regarding music and speech will not be included in first release. I would love to, but it is also a matter of time and money. Our plan at this stage, is, to include more customized music, and all speech into the free version, and then update the full version.

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Mission intro

I am very very close to completing NightFlight. I plan on sending the game to Apple mondag next week.

Latest addition is the “old movie” intro from noisy B/W to the normal game setup.

Pretty cool if I might say so :)

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