ramblings of a madman

Bears with bounding volumes

2011-09-21T07:18:00.000-07:00

I recently started to add some primitive collision detection to be able to place objects to scene without them overlapping each other. I calculate bounding volumes during parsing of the object data. Whenever a new vertex comes in I test it for current min and max for x, y and z. Then in the end I calculate midpoint for the mesh as well. I added a debug mode to see the bounding volumes during rendering and this is the result. This is all simple and makes development and debugging much easier. Highly recommended step to do at the very beginning.

I've also rewritten the scenegraph part of the engine so that all CPU work (like the matrix calculation) happens before any GPU work. This meant a lot of refactoring but now I can enjoy much higher FPS rates even with a lot of complex geometry like exploding the buddha mesh and so on.

As next step I will experiment more with the explosion stuff, I want to add more physics. I already did some trials to rotate triangles while they fly but it did not really look that good, I probably will try to add per triangle velocity vertex attribute and apply gravity so that the pieces fall down. One problem also is that when I do the explosion in vertex shader my bounding volumes are not reflected to this change as shown below.

Exploding objects

2011-08-09T10:59:00.000-07:00

Few months have passed and I've basically rewritten all internals of the engine. Now there is much more generic scenegraph with nodes that reference to objects that then may have one or multiple meshes. While cleaning things up I removed a lot of unnecessary calls bringing some performance up and making it simpler to test more complex scenes. There is a factory class to create terrains and tunnels dynamically and in the future possible other meshes. I also wrote freetype2 support so that it is easy to test and use different fonts.

I started to write 'effect' support which in practice means that scene will pick a particular shader program attached to the node and animate its attributes, offsets and so on. First I started to work on 'explosion' that animates vertices along face normal with an offset. I'm pretty satisfied with the results so far. Plan is to either fade away pieces while making them smaller, or possibly just let them hit the floor after initial 'radial' movement.

Normal tricks

2011-05-23T09:39:00.000-07:00

I just spent some time rewriting the model loader. Old one was originally done to a software rasterizer and did not handle per vertex normals correctly. Now that I *finally* rewrote it, I can remove quite a lot of code that just sit there because of dependency reasons with the old SW engine :) Now mesh can have 2 modes, one with face normals that make the object look a bit like a sculpted wooden statue and another mode with per vertex normals that implement Blinn-Phong 'correctly'.

Wood statue :

For wood statue each vertex in a face gets the face normal, so each vertex normal points to the same direction.

Blinn-Phong :

For Blinn-Phong each vertex normal is the normalized sum of normals of all adjacent faces to the vertex.

Light scattering

2011-05-14T09:54:00.000-07:00

I got bored with the engine and decided to just play with effects for now. Here is real time light scattering, like explained in in Fabien Sanglard's blog. I plan to mix this with the earlier bloom shader and see if the thing still runs 60fps. It seems Acer laptop did not like light scattering though, both CPU and GPU temperature peaked very high and my laptop powered off itself, maybe some optimizations needed, eh :)

Hairy Balls!

2011-05-03T12:09:00.000-07:00

I started to try out a bit more experimental things and implemented sort of a grass effect by abusing the normal data and drawing some GL_LINES per vertex. Looks nice, needs some more touch though ... more on that hopefully later.

Happy Buddha

2011-04-29T22:25:00.000-07:00

Lighting is now fixed and speculars are finally moving according to camera and light position. In the end bug was simple but hard to notice, I forgot to normalize camera vector in the shader which made it *very* big compared to light vector in the lighting equation so light movement did not cause any changes and only camera did. Also pick feature got fixed on the way while porting recent changes to win32 build. Now it is time for new features and optimize the mesh loader, it takes ages to load buddha model :)

tiger power

2011-04-28T03:46:00.000-07:00

I rewrote my model loader and now there is support for multiple polygon groups and texture coordinates. Thanks to models and nice texture atlases from http://www.kunzhou.net/tex-models.htm I'm able to test that engine works. And then the bad news, while doing all this I noticed that lighting does not actually work, picking does not work anymore and some other misc stuff, but it was necessary price to get rid of old obj loader, time to fix these things.

let there be light

2011-04-21T05:21:00.000-07:00

Took a step forward to more 'game engine' approach and implemented a first person camera control with mouse and strafe with keyboard. Added terrain and much more sophisticated lighting and material model.

Teddybears

2011-04-20T08:26:00.001-07:00

Dear diary, once again I started to build a small 3D engine, this time with OpenGL (ES) 2.0. Engine works fine with Linux PVR SDK, MESA software GLES 2.0 and MS Windows Nvidia OpenGL SDK. Engine contains a simple scene with objects (supports only .obj format at the moment) and a final full screen postprocessing pass. Objects are stored in VBOs and simple light model + bloom/blur is implemented using shaders. Engine provides a resource hash and memory management for shaders, textures, FBOs and other GL resources. Picking support (red teddy has been selected) now uses FBO and renders one extra frame with simple color shader. The end goal is currently to have a simple sandbox where to test different OpenGL features.

Ultima VI

2008-02-11T22:13:00.001-08:00

Last weekend I bought Ultima VI for my Amiga 1200 from recycling center for 5 euros :-) It runs very well from disks but hard-disk installation requires booting to non-AGA mode from early startup screen (toggle both mouse buttons when booting) + game hangs after character generation and startup movies :-/ Game itself is really nice still, it's old age does not really show up as graphics are good, only thing that really bothers is the amount of disk-swapping ...

PS3

2007-11-18T23:45:00.000-08:00

I *finally* went to shop on last friday and bought PS3! So far, I'm *very* satisfied with the thing, Motorstorm rocks and really shows what is possible on nowadays consoles, lots and lots of details and shader effects. Apple bt-keyboard paired nicely however it did not like the one button mouse, time to buy better one :) Looking forward to install Linux into it on some upcoming weekend!

Commodore + SNES

2007-07-08T08:12:00.001-07:00

Sometimes it is hard to connect dots! I bought a Commodore monitor month ago to have it for my C-128 ... never got it to actually work. Only now I realized that I have a composite video cable for my SNES and tried it out ... WOW it works :-) Snes-mouse is there just for curiousity ... maybe you did not know it exists ?-)

A glass of whiskey

2006-11-09T12:57:00.000-08:00

It's probably been too long time since I spent evening hacking and drinking 'Famous Grouse' ... (don't think I don't know better whiskeys, I just like to have them cheap). I have left 'libenkine' for awhile and gone back on GL (but on my minimac this time :-). I think I'll spend some time thinking how to make a simple landscape attractive ... flatshading should be enough for everyone, right? Well ... I'm having textures there, I've made a simple API to update textures which seems to be fast enough for small purposes but now it's bugging .... urgh .. I guess it's time to goto sleep!

libenkine

2006-08-03T09:52:00.000-07:00

yesterday I spent my evening hacking on hedgehopper game (https://garage.maemo.org/projects/hedgehopper/) and (as was originally planned) started to separate game-engine as a library called 'libenkine'. libenkine will contain tilemap and spriteclasses + engineclass to handle these (and other stuff) but also primitive drawing + surface manipulation, so it can also serve as a simple graphics API. the ultimate goal is to make game development a simple task, basically just building a tilemap level with editor and producing a textfile which describes what sprites it will contain. yep, I know there must be dozen game api's done on top of SDL and propably it sounds crazy to implement another one ... but when checking out the existing ones I find them complex to use. one big goal for libenkine is to provide a minimalistic api to have a game running + lots of additional tweaking functions to modify behaviour of sprites but only if one wants to do so. I will test libenkine on 770 and try to have it working for GP2X aswell.

rescue set

2006-05-04T09:55:00.000-07:00

Just wanted to note that if you experience problems with 770 , don't worry! Rescue Set is on it's way! :-)

winter games

2006-03-09T23:39:00.000-08:00

Long time no sea ... I thought to post some photos here to show that I'm still alive and kicking! It's winter finally .... that photo has been taken weeks ago though :) Here's a more fresh one :

Walking in the ice of baltic sea ...

gp2x

2006-01-18T22:50:00.000-08:00

Yesterday I visited my friend Subjik who is a lucky owner of a gp2x handheld console. Very nice machine for handheld-gaming ... 320x240 is quite enough and the controller is very good. What is the coolest thing for me is that this is actually the first handheld which you can use to play commodore-64 games without pain. The controller feels almost like analog joystick, SID emulation rocks and Frodo emulator menu is nicely designed. In fact I liked the controller more than the one in PSP. Only thing missing is wlan for network gaming :-/

playing roles part ][

2006-01-15T11:13:00.000-08:00

Our journey continued, my elven fighter/thief 'Ermil' managed to raise a level after some successful bashing of a very evil man :) We took a visit to a Duergar lair and managed to escape before getting slaughtered! Also played quite much of 'Donkey Kong Country 3', which is one of the best platformers ever ... especially if you have played DKC2 it will make you laugh and enjoy!

more colors

2006-01-02T11:22:00.000-08:00

OK ... I have to admit that this is just too much fun. I also added a poor man's blurring-effect but it does not look nice enough yet ...

growing trees

2005-12-29T03:59:00.000-08:00

I like Darwinia a lot. That's a game you *have* to try if you haven't done it yet! I could not resist to start making own procedural graphics stuff :) The web is full of nice tutorials and explanations how this is done. Recommended to read : new science. Very big fat book but contains useful algorithms and nice pictures.

<3 OpenGL

2005-12-22T12:44:00.000-08:00

Listening to Boards of Canada and playing around with OpenGL ... Mirror-effect is done by simply copying the whole framebuffer as a texture (glCopyTexImage2D) and blitting one quad with a slight drop of blue in it. Flares are nice, I think I'll write some kind of intro/demo when I have more ideas :-) BTW Texture used in cube is from one of my favourite anime movies .. Laputa : Castle in the sky.

sauna

2005-12-19T21:46:00.000-08:00

Visited Porvoo in the weekend. Very nice city! Apparently cats over there like sauna quite much :-)

xrandr -o 2

2005-11-30T05:26:00.000-08:00

Wanted to note here that screenrotation is possible with 770 hardware (without speed or memory loss). Let's hope to see this candy soon in MAEMO releases :-) Thanks to Mallum for telling me howto fix mouse coord rotation!

tileset/tilemap editor

2005-11-28T12:55:00.000-08:00

I just realized that I have to finish the mapeditor before going any further with my platform-game ... making a good editor is a bit boring but it will surely have profit on level design and better gameplay ... just wanted to note that platform-project is *not* dead :-) Going to sleep ..

770 as a controller

2005-11-17T01:35:00.000-08:00

This morning I bought new Edge magazine and noticed there's a picture of 770 but it has a analog stick on it :-) Pretty nice mockup, it was designed as a controller for Nintendo Revolution console.

Check out the '770 controller' picture here :
http://img75.imageshack.us/my.php?image=revcontroller5rm.jpg

And rest of the mockups :
http://www.4colorrebellion.com/revolution-controller-mockups

Actually 770 could be nice gamecontroller for some x86 strategy game, a controller with a screen, this is what Gameboy Advance can be used for some Gamecube games.

platforms

2005-11-12T04:36:00.000-08:00

Here are some screenshots of platform game I've been working on. Graphics are taken from a nice c64 animation site http://www.abc64.de/ since I've got no graphics skills myself. Big space below is caused by blogger layout, I don't know why.

Oops, did I say that?

2005-11-02T00:18:00.000-08:00

OK, now that I've been playing 'Dungeon Siege II' a bit more I can review a bit more. The rpg-feeling is starting to fade away and the game reveals it's true nature, which is Diablo2-style hack'nslash orgy. The environments, characters and the plot is very nice ... but still ... you end up smashing thousands of monsters which happen to stand right in your way. Magic spell effects are really nice but lacking voice variations. When you kill 1000 monsters with same spell making the same voice it really starts to annoy you :-/

Learning to fly

2005-10-31T12:08:00.000-08:00

Rotating starfield, rotating cubes and ship ... points, lines and a quad - simple is beautiful :)

Those of you who like old videogame/demo music, put these to your 770 favourites :

http://kohina.com/
http://scenemusic.net/
http://www.slayradio.org/home.php

Turrican!

2005-10-27T11:03:00.000-07:00

Mmm? What's that? Hatari - atari emulator running Turrican II on 770? Yes, that's what it is :-) Runs fine but yeah ... controls are a bit sucky... you cannot really play it since it's fast paced especially on later levels. (hatari was ported to 770 by my workmate Eero)

Turrican II has been my favourite shootemup for a long time. It has very cool weapons and graphics. Especially I liked the amiga version (haha this could be actually a nice opportunity to start new flamewar between amiga and atari again ...), all true Turrican fans should also remember that there's a new one, T3 released 28 August 2004 for Commodore 64 by Smash Designs ... http://noname.c64.org/csdb/release/?id=14321

3D

2005-10-24T23:21:00.000-07:00

Yesterday I experimented a bit with TinyGL (software implementation of 'most important' opengl commands) and Nokia 770. I modified TinyGL to open window in fullscreen mode. Wireframe objects were running fast and I am planning to make a 'asteroids' clone using this, lighting and shading produced problems ... framerate goes down like cows tail, I'm not sure yet is it the floating point calculation or blitting speed in general but I will investigate it. Patch will be submitted here when I have something nice done :-)

Stoned!

2005-10-24T23:19:00.000-07:00

A word of advice : if you ever happen to meet a greater abyssal basilisk, do not look in to his eyes ... it will turn you to stone. We had some great adventuring during the weekend and my thief/ranger character raised one level! :-)

Playing a different role

2005-10-18T22:51:00.000-07:00

I've been playing 'Dungeon Siege II' quite much lately, nice game! There's lots of things oldschool roleplayers will recognize familiar. For example discussions between own group npc's (Baldur's Gate etc..), you can take a pet as one character in your group (Nethack) ... by feeding stuff to it, it grows and becomes a stronger ally, teleports (Diablo2 style) .. no need to travel again that same route ... except most of the subquests are made in travel routes made for the major quest and you notice often to be *again* in that same area. Nice game anyways, it feels like a real rgp adventure ... You can even pause the action by hitting space and think again! I've been waiting that feeling since Baldur's gate 2. I liked Neverwinter Nights aswell, but something just wasn't right about it, I honestly don't know what. Next weekend I will play some AD&D with friends...

First post!

2005-10-17T00:13:00.000-07:00

Hello there,
I have thought evil thoughts about blogging for a long long time but now eventually decided to start one :-) This blog will include at least some coding tutorials, my opinions of music and movies etc .... propably works as a personal diary aswell, but I'm trying to avoid that.

I bought "Children of Dune" dvd in the weekend and watched the first episode ... it was quite nice, don't expect cool computer visuals though. If you have read dune book(s) I recommend to watch this one.

http://imdb.com/title/tt0287839/