Refractive Sphere

After a lot of days of silence, let's start again the APOCALYX 3D Engine daily posts. Today just a short old news: I simply signal an old paper of mine that describes how to simulate a refractive (and reflective) perfect sphere with just two triangles.

In DemoPack1 is available a demo (RefractiveSphere.lua) about the subject.

The article dates back to 2004, so it explains how to simulate a sphere through fragment programs. Now the same effect can be accomplished much more easily using fragment shaders and the GLSL language, but the theory behind the scene is still interesting.

Download the paper from here: RefractiveSphere.pdf.

Third Person Shooter (II)

Other screenshots from Miguel Manchego Rivas' Simple Shooter.

You can download the demo from the Users' Gallery. Feel free to submit your little demos, even if you find the quality of yours worse that Miguel's ones. Thank you in advance!

Third Person Shooter

Other screenshots from the Miguel Manchego Rivas' demos. This is the time of the Simple Shooter that you can find, as usual, in the Users' Gallery.

As you can see, the features of the demo resemble those of my Urban Tactics. The main important different is that the avatar can jump and walk on ramps, while in Urban Tactics the level is completely flat.
Another difference is the use of level items (items placed in the GtkRadiant Level Editor) to place objects, such as medikits, in the scenery.
Both these improvements were already available in Treasure Hunter, but jumps are much more fluid here.

Treasure Hunter (II)

Other two screenshots from Treasure Hunter. Visit the Users' Gallery for more.

Treasure Hunter

Just a few screenshots from "Treasure Hunter", a side-scroller demo realized years ago by Miguel Manchego Rivas.

If you have developed games or demos using APOCALYX, feel free to submit them, even if they use very few functionalities. I'll be very happy to host them in the Users' Demos page.
Thank you in advance!

Unicode fonts

Another quite hidden feature of APOCALYX is the support of UNICODE true type fonts.

You can find a demo showing how to display UNICODE true type fonts in "UnicodeTrueTypeFonts.lua" included in DemoPack2.
As you can see in the screenshot, after a true type font has been loaded in the engine, there are several different ways to use it to display texts. This feature is brought to you thanks to the FTGL and OGLFT libraires included in the engine.

Multiple viewports

Probably this is one of the most hidden features of the engine, but APOCALYX can also support multiple viewports.

There are several kinds of viewports: first of all, the world scene can be seen from different points of view, then also other simplified 3D worlds independent from the main scene can be rendered in their own viewport. To see the feature at work, try the "Viewports.lua" demo in DemoPack1.

New MekaWars demo!

The second MekaWars demo is finally here!
You can download MekaWars.zip from SourceForge (2.5 Mb)

Since the first demo was very primitive, this new preview includes several improvements:

• a static initialization screen
• an options screen with animated models
• users can choose the number of units
• radar tracks shown in the 2D viewer
• two different programmable teams
• improved info and Lua documentation
• a Lua language programs editor

Please, report any problem that you can experience with the new demo and feel free to post here comments, suggesions and constructive criticisms about the MekaWars simulator.

The 2nd MekaWars demo (II)

The second MekaWars preview is almost completed. In the screenshot you can see a preliminary mask to modify the number of items in the arena. The upload is scheduled for tomorrow afternooon.

The 2nd MekaWars demo

The second MekaWars preview is under development. The next demo is going to include some masks useful to personalize the test arena. Stay tuned!

MekaWars very early demo

Since a reader has asked for it, I have uploaded a very early demo showing the MekaWars simulator at work. Don't expect too much: it's only the 2D viewer that I used in the past four weeks to capture a few screenshots and demonstrate some of the simulator features.
You can download the MekaWars very early demo (1.5 Mb) from SourceForge. Just for blog readers' eyes only.

Here just a few notes follow to describe what is available in this very simple demo (read the included readme.htm file for more details).
First of all, let's explain how to play. MekaWars is not going to be an interactive space combat simulator: it is based on the same design of JRobots, thus it is a "programming-game", those games where players program the AI of their team of bots and then watch them fight against other players' teams.
In the demo, you can experience only a few features of the real simulator and the situation at the beginning is always repetitive: 2 fighters and 6 harvesters that always start from the same positions, while asteroids and resources change the position at random. In practice, you must fight against yourself to see some action.
To develop the pilots' AI, you must program in Lua the file 'pilota.lua', that already features a few lines of simple behaviors. In the readme.htm, you can read a short list of the available functions.
Feel free to ask for any additional explanation and stay tuned for more interesting, more complete and more playable demos.

Lost Garden Bronze Award

The results of the latest Lost Garden's Prototyping Challenge (Shade) are finally available. My entry was one of recent APOCALYX demos: Mushroom's Ride.
Unluckily I released it without implementing the main design requirement: take advantage of the shadows to bring the mushrooms at home (read the release post).

This design requirement was fundamental, that's why the entry received the bronze award instead of the silver one, that I tried to achieve. Anyway, seeing the quality and variety of the one and only entry that deserved a silver award, the result is not so bad.
Thank you Danc (the owner of Lost Garden) for your interesting game design ideas and your great graphics.

Andrea Orioli's models

Yesterday I forgot to mention the other models shown in the MekaWars' trailer. They are the well known vehicles already used in Hoverjet Racing.

They come from an Andrea Orioli's old project known as Black Chaos, a clone of the old Wipeout 2097. He kindly gave the permission to use them in Hoverjet Racing and I find them so good that I use to include them as placeholders also in other projects.
Being a high-level graphic designer, Andrea finds those models obsolete, in fact after those first attempts he designed more advanced models for the same project and developed also professional models for commercial games. If you are interested, visit the Andrea Orioli's online portfolio.

Above you can see the new version of the Black Chaos vehicles, while below you can see some very suggestive buildings taken from the scenery where Black Chaos races had to take place.

Demos modifications

Sometimes I receive requests to modify in some way this or that demo. I'm surprised by these requests because I always explain that one can easily modify the demos himself. For example, it's very easy to change any resource used in the demos (textures, models, sounds etc.). Take for example the latest demo, Mushroom's Ride, posted two days ago and let's change the player's avatar. Since the avatar is a MD2 model (the old Quake2 model format), it's simple to take one's own preferred MD2 model and replace it. In the screenshot below, you can see that I have simply replaced the original fairy with an orc.

Some of the animations are different, of course, but the convention implied in the MD2 format makes coherent the overall behavior. To replace a model with another, or modify textures, sounds etc, one simply opens the "main.dat" file as it was a ZIP file (effectively, it is a ZIP file renamed to DAT).
Other more complex modifications need some knowledge of a programming language. For example, in the screenshot below you can see that the height of the camera over the ground is lower than in the original demo.

To make this kind of changes one can open the "main.lua" file with his text editor of choice. Doing so the complete source of the demo will be available for one's modifications. Usually the sources of the demos are short and quite structured, then downloading the documentation of the engine at the APOCALYX Downloads Page, it's not so difficult to understand the meaning of the variables and functions. In addition, the Lua language is very intuitive for people who already knows another programming language and, being scripted, no recompilation is necessary: one can immediately see his modifications at work.

Mushroom's Ride released

Finally, here it is: a new APOCALYX demo, Mushroom's Ride. Move the fairy through the stone blocks to collect as many mushrooms as possible. You can download it from SourceForge. The 1.3Mb ZIP contains also a stripped version of the engine executable (only 414 Kb), so you don't need to download the larger runtime.

This is only a demo, in fact the gameplay is not complete. For example, the shadows does not affect the mushrooms' behavior, as originally intended. Anyway the sources are included so users can easily modify and extend the demo at will. In fact, as usual, the source is written in a *.lua file, that one can modify with a simple text editor, while the data is included in a *.dat file, that is nothing else than a ZIP renamed. Enjoy the demo!

Mushrooms fields

Another screenshot about Mushroom's Ride. Finally the fairy can run through the stone blocks on the mushrooms field.

Now it's time to implement the game logic:

• as time passes, the sun moves in the sky
  
• when the fairy approaches a mushroom, it keeps following her
  
• when more mushrooms follow the fairy, they create a chain (each approached mushroom starts following the last mushroom of the chain)
  
• when mushrooms stay too much in the sunlight they shrink and disappear
  
• when mushrooms reach the goal the score is incremented
  

Shadow Volumes

Latest improvements in Mushroom's Ride: finally the shadow volumes applied to static meshes are rendered correctly, as you can see in the screenshot (one of the fairies is partially covered by the shadow of the cube).

However the performances are not the best yet, in fact the shadow volumes are applied on a per-triangle basis. This means that for each triangle enlighted by the sun, other three triangles are rendered on the stencil buffer, triangles that extend to infinite, so become particularly large at certain angles.
A better way to implement the technique is to find the outline of the shadow, given by the edges in common between two triangles, one enlighted and one shadowed. In this case the number of faces is reduced a lot. It's not difficult to apply the technique on static meshes, but is more difficult when applied to different animated model formats. Since APOCALYX does not implement his own format, but supports a lot of them, it's necessary to write specific code for each one. Implementing one shadow volume per triangle is simpler, but performances degrade rapidly when the models are not low-poly.

Mushroom's Ride

First screenshot of Mushroom's Ride, a prototype in development written for the Lost Garden's Shade Compo (read the original post about the Lost Garden Awards).

As you can see, to fast prototype the game I'm starting from the sources of Dragon's Ride because there is no time to reinvent the wheel again and again. In place of all the models features in Dragon's Ride, I simply put two fairies: they are going to lead the mushrooms to their goal, moving along fresh shadows and avoiding the hot sun.
Now I'm going to model a few mushrooms. As you know, my modelling capabilities are very poor, but I must admit that mushrooms are not the most difficult thing to model in the world... or, at least, I hope so.

Users' Gallery

I know that the documentation of the engine is not simple to master. Probably I had to focus a little more on getting started papers, rather than big lists of functions. However I think that learn by example is a good way to... learn, so the source code of the demos is the best starting point for new users, if they already own intermediate programming skills. I provided a quite large number of demos on every possible topic, especially fundamental topics. I wrote also a few more complete game-like demos, but interesting examples were provided by advanced users, too. Visit the Users' Gallery to download a selection of users' demos.

For example, Miguel Manchego Rivas wrote Treasure Hunter, that is a side scroller shoot'em up demo. It performs an original use of the entities placed in a BSP level, a basic control of the avatar and shows hot to manage custom MD2 animated models.
Miguel provided also a demo about a third person view shooter with advanced jumps, more complete in comparison with my Urban Tactics, where the level is flat and jumps are not considered.
Then Robin Knight wrote a first person shooter demo with a large level, lot of enemies and powerups. The demo includes also an interesting tutorial.
If other users want to donate their demos and trials to the community, I'll be very happy to publish them on the APOCALYX site.
Thanks to all those who are going to contribute!

Transformers

Probably you think that I've forgotten "City Racing", but that's not true. Now I spend my spare time in the development of "SOCCER TACTYX" because this is the right period to take useful inspirations from the matches of UEFA Euro2008, but "City Racing" is always the next demo that I'm going to develop.

For what regards the car models performed in that demo, I've already chosen those shown in this old post, but I've recently found also these nice models in the "Transformers Q2" MOD for Quake2.

It's surprising to see these running cars or flying airplanes tranform seamlessly to fighting robots, so it's not a bad idea to archive these models and take them in consideration for a future demo.
Imagine a slow running robot that becomes a fast racing car: I don't know yet what it has to do with with a race in the streets of a towm, but at least it's amusing!