RGP day 15 - AI and a download link

So, as promised, I am finally giving you something to play with.

AI
I have added a very basic AI steering system and obstacle avoidance behaviors. I will write a more detailed article about it soon.

physics and handling
I completely rewrote handling and physics system using real world laws of aerodynamics. It was a really nice exercise and gave me the basic understanding of movement, drag, acceleration, etc.
The movement is now much smoother and the vehicle is very stable.
all math came from here: http://physics.info/drag/ & HERE
I will write a more artist-friendly overview of the physics behind the game.

UI
added subtle motion to the UI while steering

camera movement
The camera is now more dynamic. FOV, height and distance from vehicle increases with the velocity.

post-process filters
added a simple lens filter that distorts, blurs, creates vignette and adds some chromatic aberration near the edges of the viewport. I might make it react to the velocity as well.

a video:



and a download link to blend: https://dl.dropbox.com/u/11542084/RGPv01.zip

Now I have to finish few projects, so this is probably last (RGP related) blog post in next few months.

RGP day 10 - a bit of everything

First post in 2013, and I feel it is going to be a great year :]
I know it`s been a while, but I am working on the game again!

It is actually day 10 - 14 of the RGP. I worked on the project quite a lot, mostly tweaking the code to make it work just right. And finally here is also some visual stuff, while only sketchy, but something! So here is the stuff I`ve been busy these last 5 days.

physics and handling

I`ve been collecting some useful resources regarding physics, acceleration & springs`n`dampers aswell as browsing through YouTube videos of Wipeout, F-Zero and other futuristic racing games. I believe now that a nice vehicle handling system will be actually much bigger challenge than I initially thought. I hoped I could stay with Blender`s built in Bullet physics & material properties in UI, but I just could not get the feel and handling right as well as it caused stability issues at high speeds. So I created my own system. Basically it consists of spring-damper system for vehicle suspension, engine system for thrust and turning and a very basic inertia and gravity system.

race track & vehicle

I made a race track to push my physics system to the limits. Basically it is an oval loop with a twist - literally :).  I created a race track based on Möbius strip - "A model can easily be created by taking a paper strip and giving it a half-twist, and then joining the ends of the strip together to form a loop". So you are actually racing on the both sides of the race track. Also the oval in the middle is bent around 90degrees up which at high velocity, will create very high negative or positive centrifugal forces, so that the race car will be either pressed against racetrack surface or pulled off it. In the game speedways will have a gravitational force field which will keep the race cars from falling off the track either at high centrifugal forces or regardless if the track is upside down, so I think that this kind of racetrack configuration is perfect for testing and tweaking purposes.

overview of the "Möbius race circuit"



clearer view of the configuration



This is a generic racecar you would find in similar racing games. As the rest of the game this is only a placeholder. More race car concept-art is on the way :)



UI

This is the first time I am working with Moguri`s BGUI - a graphical user interface (GUI) library for BGE. I have just started to mess around with it, so nothing much to see yet, but I intend to keep it simple and minimal, close to what you can see in the screenshots below.

Camera movement

I worked also on the camera movement a little. A good setup can add a great amount of immersion into the game. Just parenting it to the race car`s chassis does not look good. I will do a deeper look at it sometime later.

Graphics & FX

Nothing fancy yet - a simple skylight setup like THIS, completely texture baked terrain, simple fogging that gives an atmospheric feel. Exhaust trails are cross shaped , textured planes spawned each frame - I should find some more efficient way of doing them.


screenshots showing all of this together which starts to form up the feel of an actual game:













(I am having some difficulties with screen capture software working on Windows 8 so perhaps I will switch back to win7 to be able to make some videos)

Back to Win7 and video is here.



blend file is on the way.

BGE Candy - Area lights

I have a new PC computer and this is a milestone for the development for BGE and my racing game. Finally I can to some more quality screen capture, and the first ones to show you are - area lights!



As soon as I saw Arkano22`s implementation of area lights in gamedev.net forums I knew Blender must have it in GE! This is a slightly modified version of Arkano22 technique, the biggest differences are the smoother light falloff and specular reflection glossiness variations based of the reflecting surface properties and distance, and of course - the texture support!

video showing how to set-up them:



win32 build: https://dl.dropbox.com/u/11542084/Blender246AreaBuild.zip

RGP day 9 - physics

So today I am doing something completely different I've done so far - the physics system. It is the next big challenge aside from the track coordinates and AI.
For collision detection and simpler stuff I will be relying on Blender's Bullet Physics system, but more advanced things - track space constraints, hover spring-damper system, vehicle handling and behaviors I will have to write from a scratch. And as an artist I am very good at it :P. Fortunately we have an Internet and there are a lot of really helpful resources for this.

The first thing I tried to implement was a mass-spring-damper system. I will be using it to make the vehicles levitate above the ground/racetrack surface. The idea is to cast a ray from the vehicle's vertical axis down. If it collides with a surface the spring-damper simulation will run and apply the calculated force to the vehicle.
The most helpful resource I found had an actual Blender Game Engine implementation already :). HERE is the link where I found it. It is done by Sebastian Korczak, same guy who is making the Burster - a web browser plugin to allow publish and play Blender files online. I will be using it at one point of development to show off the progress.
So after some changes I had a nice springy levitating box.

Another thing I managed to create - a force field that will keep the race car close to speedway's surface, thus preventing the vehicle to fall off the track surface even if the speedway is oriented upside down.

blend file HERE

shader based cube environment mapping

I present you a pure shader based cube environment mapping. It might be useful for those who, for whatever reason, does not have "samplerCube" texture type support in their engine or want some more flexibility or customization for envmaps. It is a tiny bit slower than the proper version and mip-mapping is not working well, so it is pretty much useless.
This paper helped me a lot: http://www.cs.wustl.edu/~cmg/content/papers/jgt2007em/jgt2007em.pdf

Anyways, the input can be 6 separate textures or cube environment map Blender style. A standard OpenGL style alignment is on the way.

shader HERE

screenshots are in previous post :)

//status update 04 & RGP day 8

Lots of good stuff has happened recently. I am waiting for my new custom laptop to get shipped from US, so finally I will be able to normally screencast the process of the development of my racing game ..and to actually play my game. As a real tech geek I will also write a short review of it :)
Not much has happened to RGP since the last post and I believe the real process will start whenever I will be on my new rig.

Here is the list of stuff regarding RGP:

- So for the outdoors lighting in the game I will be using a procedural sky model originally presented in 2002 GDC by Naty Hoffman and Arcot J. Preetham. Implementation by Simon Wallner seemed to be the best one I could find and I have already got it working in BGE (see it HERE). I thought I was quite satisfied with the results, but just few days ago some guy asked for an assistance regarding the sky shader as he is implementing it in UDK4 engine. It turns out I had seen his works numerous times and visited his portfolio earlier, be sure to check it out HERE <- awesome stuff! Anyways he also pointed out that it lacks the distinct sunrise feel to it so I took another look at the shader. After few modifications I came up with a nice sunset/sunrise effects.
- I also added a Uncharted2 filmic tone mapping operator from John Hable's GDC presentation and implementation of it from HERE. I really Hope I can add a real HDR support in BGE someday.
- Another feature I have been trying to replicate in BGE is generation of cubemap environment maps in real-time. I did it by simply rendering textures from 6 cameras and then combining them in a shader. It is slow but works! A simplified and optimized version of it I might use for reflection in the game.
- And the last but not least - a pseudo lens flare by John Chapman (implementation from HERE)

blends:

both files also feature point light scattering by Miles Macklin.

realtime cubemap:
https://dl.dropbox.com/u/11542084/realtime_cubemap.blend

lens flares:
https://dl.dropbox.com/u/11542084/flare_playground_3.blend

screenshots:

the upgraded sky model



real time cube environment mapping





lens flares





Battlefield3 style dusty lens



light directly into lens

RGP day7

so I've taken enough rest and today I am moving from "planning and preperation" to  "sketching and concepting" phase of the development process.

here is a fast 30 minute draft of shaping up the feel and scale of the desert planet. I will do a series of these.





Aside of the art part, today I tried Moguri's BGUI, which I will use for menu and some of in-game HUD. It looks very promising, but will require some intensive learning for me to get used to it. I am also planning to create a custom lighting engine with atmospheric scattering, aerial perspective, weather system, moon phases, etc. I will then build physics and handling mechanism on it. After I will publish first pre-alpha demo to try out.

//status update 03 & RGP day 6

it`s been a while, but no worries - the racing game project and BGE Candy is progressing. Slowly though as the spare time passes with friends and grasping the last summer days before I go back to France next week. After that aside from the job I am fully focusing again on RGP and BGE Candy.

RGP day 6

After a few days of intensive tinkering with vector math, I finally found a perfect solution to get barycentric coordinates of the track (I explained about this coordinate concept in the previous post)

I found rayCast() function in Blender`s Python API which also fetches UV coordinates of the ray intersection point. So now all I need is to UV map the race track, shoot a ray from vehicle down to track`s vertical tangent and voila we get vehicles relative position on the track.

I also made a simple racetrack trajectory recording system that records position and speed of the car at current segment. When it is recorded it saves it to a list and AI linearly interpolates between the points.

That`s it for now.

day5 - race track coordinate concept

Yesterday I had some thoughts on the toughest challenges I will have to overcome during the development.  I think it is wise to reckon them before I start the work on technical aspects of the game.
Here is the first task that got me a little worried.

getting precise player positions in the race track space
This includes for AI and player to know its exact distance from start and finish and distance from both track sides. I want to avoid any ray-checks from car to do that. It is too expensive and not very accurate. One solution is to have loads of colliders (sensors) covering the track, so whenever car touches one of the sensors we know how far the car is from sides and finish then it is possible to compare it with other cars and we know which car is leader and so on. But it is just not very efficient to manually add them for a hundred kilometers long track. 
What I have in mind is to convert world space position to track-relative position. So it would switch from world xyz coordinates to track uv coords. U would correspond to travelled distance and range from 0.0 to 1.0 where 0.0 is start line and 1.0 is finish line (not sure about floating point precision here) and V would be track width ranging from -1.0 to 1.0 where 0.0 is middle of the track. This idea comes from THIS blog post about AI coordinate system used for MotoGP. I think it is very elegant and simplifies a lot of tasks especially AI behavior and keeping them on track without using bunch of waypoints and ray-check system.


How would that work?

Vector power!
Race tracks will be made of segments which I will deform by curve and multiply with array till the end of the length of curve. Lets assume that 1 track segment is a quadrilateral (tetragon) made of 4 points. To switch to track-realtive coordinates we need to know world position for each track segment. This means getting each point of track into an array and sort them to form lines, so each segments start & end line act as sort of check point. Then for each car we can get on which segment the car is on and calculate the fraction of the segment covered with point-quad or point-triangle intersection function.

I already got a chance to implement an efficient ray-quadrilateral intersection test in BGE and it works really nicely, though I have to check performance compared to point-triangle intersection functions.

Here is a simple illustration:



The tracks will have sharp turns, loops, banks, tilts and variety of configurations which makes the work on AI really hard, but converting all to track-relative coordinates "flattens" and "straightens" the track which makes work with AI ridiculously simple.
some examples:

if (player.distance > otherplayer.distance):
    #you are ahead of other player

difference = player.distance - otherplayer.distance
if (difference < treshold):
    #start collision avoidance
    #start the overtake process?

how to check on which side to overtake an opponent:

if(overtake = 1):
    #overtake in progress
    player_ahead.width > 0.0 ? go_left : go_right
    #see on which side is more space and go
    #here we can also override previous statement to check if car width is wide enough to fit in the narrowest side and so on..

this all is just a theory now how I imagine it to work in my game. I think many commercial racing games use similar approach and it works, but they have dedicated professional programmers up to the task. will see how I can handle this when I start the work. I am open for suggestions and perhaps there is even a better solution for this.

Now I take a few day rest from the project as I am moving from France to Belgium and then back to Latvia.

Edit:
I got working the basic concept of coordinate system:
https://dl.dropbox.com/u/11542084/get_track_position.blend
If this proves to be efficient enough for big tracks then I will use it in the game.

References:
1 - http://blogs.msdn.com/b/shawnhar/archive/2009/12/30/motogp-ai-coordinate-systems.aspx
2 - http://answers.unity3d.com/questions/25189/race-position-help.html
3 - http://gamedev.stackexchange.com/questions/2382/how-would-one-determine-the-position-of-a-participant-in-a-racing-game
4 - http://graphics.cs.kuleuven.be/publications/LD04ERQIT/

water/undewater shader WIP

This is a water shader I am working on in my spare time. The work is based on my own observations of water characteristics and written from a scratch. It is still a work in progress.
Right now the water surface is a plane, but support for real geometry waves is on its way.


Due to my old computer I am currently on, I am almost unable to capture a video with decent framerate, but the shader uses simple calculations and runs very well on even 6 years old mid-end hardware.








thread on BlenderArtists HERE


blend HERE


known issues and bugs:
- OpenGL clipping plane is not working on some GPUs
- mouselook goes wacko on some BLender versions but works fine in others
- some are reporting that sun-grab is not working
- and for some it does not open blend at all..

RGP GDD (work in progress)

As I mentioned before I will post all of the development process online. Today I am making a game design document or GDD. This is the first time I am writing one on my own.
I consider GDD to be one the of most important parts of the game development process, especially if there are more than 1 developer working on the project. Well in my case this document will be a lead that will keep me on track and I do not waste time on details while there is not a solid foundation yet.

all content here is a subject to change and will form up in further development of the game. At one point I will have to make a document file. For now this is more like a verbal sketchbook of ideas and concepts not a proper GDD, so here it goes..

--------------------------------------------------------------------------------------------------------------------------------------------------------

"Racing Game Project¹"

¹I will come up with a proper title in the process


BRIEF OVERVIEW

RGP is a fast paced single player¹ racing game where the player is a pilot of ultra fast, hovering race vehicles². Game setting takes place in a distant future or a fictional parallel universe on various distinct planets around the galaxies. The aim of the race is to test the very limits of racers skills, endurance and cutting-edge technology of vehicles in various terrain and weather conditions, much like Rally Racing and Formula One.

¹ multiplayer not planned for now
² will need a name of the vehicle


STORY

Player takes a role of a race car driver born on a fictional desert planet¹ where except for racing there is not much else to do. Player has to prove that he is the best racer on the planet in order to qualify for much more prestige races taking place in different locations. Here starts player's journey through galaxies and exotic places and extreme races. As player progresses through the game the vehicles get faster and more responsive, racetracks more dangerous and more challenging.

¹planet not yet named
Edit: darn this sounds like a plot from StarWars Ep1 taking place on Tatooine...


GAMEPLAY

Well racing games is all about being first to the finish line.
The goal of my game is for player to experience the racing itself and have fun, rather than finishing the race always first, and this might not be that easy. To do this I might make different vehicle classes or groups separated by their performance. For example player starts with a lower class race car and competes against better race cars. To qualify further, player needs just finish the race, or during the race player competes in different race groups. Player does not have to finish first, but finishing at higher position in your race group is the aim. Overtaking higher class cars might make finish more rewarding. Well of course eventually the final cup becomes a fight for the first place.

But, while the game is in the development, I will focus on primary goals - having great race mechanics and make a challenging opponents.


RACE CARS

Player has a control over a jet engine powered racing vehicles able to reach speeds that exceeds the speed of sound ( in dry air -> 1236 kph / 768 mph). Vehicles are specially designed to be agile and race at extremely high speeds. The overall design is to be aggressive yet sleek, something between jet fighter and Formula-1, the design is very distinct for each class or manufacturer.  Cockpit is completely isolated from outside world as races often take place at poisonous atmospheres, very low atmosphere densities or even vacuum. Race cars are powered by a fictional power source fit in a compact capacitors that can be filled up instantaneously by being near the power source. It also powers the power-ups and onboard weapon system¹.

¹ I am not yet sure if I want add a weapons system in the game.

RACE TRACKS

As races take place in different planets the tracks vary in every possible way - track length & width, terrain, weather, hazards, even day/night cycle, etc. As the vehicles are hovering there is no need for a dedicated race track so it can take place at canyons, forests, deserts, rough surfaces and hills and even above water. Off-road racing is much more extreme and adds additional difficulty unlike on specialized racing tracks (from now on called "speedways"). Speedways offer a completely different racing experience - it is more narrow and requires more precision while overtaking and planning turns. 

Length of each racetrack might be around few hundred kilometers. Most of the tracks will be cyclic, but alternate routes will add variation in each lap. Alternate routes are an important part of a race track design. Some of them might be harder to reach, but more rewarding to use, some would shorten the track if used properly, but add risk losing speed otherwise. As I mentioned there are off-road races and speedways. Speedways are powered with a force field that keeps race cars on the track. This allows speedways to be oriented at any angle, and keeps vehicles racing even upside down. When off-road, racers have full freedom. Off road races takes place at canyons, dry lakes, oceans, hills and snow filled landscapes. The only lead that shows you that you are on the course are checkpoint marks, it is up to you how you reach them.


GAME MECHANICS


I plan to keep the controls as intuitive and simple as possible, so it has a steep or almost non existent learning curve even for newcomers in the racing genre. The difficulty of game will increase as the player progresses in the story. I want to completely get rid of manual difficulty settings in game options.

I am putting high priority on the vehicle physics. Making a race game for cars without wheels makes the task much easier, but getting the right feel and believability might be a difficult task. The ground friction is non existent (as the vehicle does not have contact with ground) I get to play around more with air friction and physics laws behind it. This involves changes in vehicle control at higher speeds, changes of pressure at different atmosphere densities or behind other vehicles.
Visual feedback as vapor cone at high speeds and humid environments will add more realism in physics presence.


PRESENTATION

Having a memorable and unique visual style is one of the most important tasks in the development process.
As I have graduated in fine arts, I feel that visual aspect of the work is one of my strongest sides. I am planing to keep the game in somewhat retro futurism style, like seen in 60s - 70s futurist artworks - smooth, bright, shiny and simple, but in the same time functional and realistic.
As a professional shader designer I will focus on creating the game visually stunning and physically plausible using atmospheric effects, smooth lighting, volumetric clouds, smoke and fog, dynamic FX and sophisticated post-processing. As the hardcoded lighting engine in BGE is currently quite limited, I will make a completely custom lighting, shading and effects engine, written from ground up completely in GLSL.
(to be continued)

REALIZATION

I am making my game in Blender Game Engine (BGE). I am a long time BGE user and I know what it is capable of as well as its limits.

This is how I plan to split the realization process.

- planning & preparation
- sketching & concepting
- developing game core mechanics
- developing graphics and shaders
- developing game art
- developing sound, graphics & effects
- putting all together
- playable alpha version
- debugging

planning and preparation
Is stuff I am doing here right now - collecting my ideas and putting them on paper. Gathering inspiration - watching videos, images, reading books. Drawing sort of an initial roadmap for the development. Having a good rest before sketching and concepting. Taking a rest nicely fit in this schedule as I am moving back from France to Latvia.

sketching & concepting
Taking a look at collected ideas, then getting rid of complex and stupid ideas and keeping simple and good ones.
Making sketches and concept art of environments, vehicles, characters, menu, HUD, overall style, etc.
Alternately "sketching" the game code, making code snippets and proof of concepts. Visualizing it on paper how all pipeline interacts with idea to have easily upgradeable system. Creating a simple test vehicle. Making of a playground for testing gameplay, car handling and physics, tracks, controls etc.
Making of first track sketches with placeholders. Testing it over and over again till it plays right.

developing game core mechanics
Taking the "sketched" game code and clean, polish, and make it solid till basic gameplay works and I have something to build further features on.

developing game art
Here starts track building from track sketches, car making from concept art, texture painting, menu creation, prop modeling, etc.

developing graphics,  sound & effects
Making of unified shading system as I plan to have every material for the game to be completely hand written. Making particle effects. Recording, mixing, and making of sound effects

putting it all together
as fun this sounds, it is actually a long process of separating directories, optimizing models (LoD), linking them to scenes, optimizing scenes, adding collision meshes, optimizing shaders. Then comes lighting, adding effects and testing & tweaking till it looks and plays right.

playable alpha version
fun part for everyone, game-testing, collecting bugs and stuff.

debugging
ensuring that bugs does not distract game experience.


INSPIRATION

Here is the list of games and artists which I consider my mentors for this project:

1. Wipeout series from developer Psygnosis is first title everyone mentions when seeing concept art. I am a big fan of Wipeout 2097 (1996, 2002 Mac), which I used to play on my old Mac a lot.
2. Sparth (Nicolas Bouvier) is my favorite concept artist since I started game-dev as an artist in 2006. The atmosphere and feel in his works is the main inspiration for environments of my game.
3. Star Wars Episode I: Racer by LucasArts (1999), awesome game. Love the race tracks, feel of speed, sound design, etc.
4. Syd Mead does not need an introduction :) or does it? he is awesome!
5. DethKarz by Melbourne House (1998) - an underrated futuristic racing game with beautiful visuals for the time. basically Wipeout + wheels.
6. John Wallin Liberto
7. Extreme G Racing series from Acclaim -  Extreme G2 (XG2) (1998) finally a game where you can break the sound barrier and it is actually shown and heard
8. Vyle (David Levy)
9. F-ZERO series
10. Goodbrush (Craig Mullins)

--------------------------------------------------------------------------------------------------------------------------------------------------------

day3:
just posted first version of GDD. It is awesome how much things get clear while writing a game design document. I did not put even half of my initial ideas, so that is the work for tomorrow. I feel that much of the game will form up while writing more in-depth description for each of the planets, cars and the technical details.

day4:
updated some stuff. I had a 3 day holidays, but I am back now. I got prematurely a little worried about technical stuff like getting precise relative position of each race-car on the track. But I consider this as a healthy challenge and extra experience in vector math.

day8:
added stuff in "PRESENTATION"

RGP day2

After a free screen-cast application roundup for Mac, I came to a conclusion that VLC is by far the best one. Still on this old and slow Mac I found it hard to work in Photoshop while screencasting even at 1fps.

So here is a vehicle concept:





This is done as an exercise and test before I start my work on the game for real. Mostly to test out sketching workflow and screen-casting.


I have not thought of the title of the game yet, but for now I will call it "RGP" - Racing Game Project

Next up - game details and putting all my thoughts and ideas on a paper (in this case - blog)

a new game project

while working on "BGE Candy" I realized I need a game I can apply the new features on. The idea of the game has been brewing for a while in my head now and I feel it is mature enough to start developing it further. I have not been sketching for few years already, so my hand needs some training..
Here are three first drawings, you can guess the genre from these already :)

(took me few hours each)







I will try to keep the visual style of the game as clean as possible using mostly gradients, nuanced lighting, atmospheric effects, vertical shapes and simple geometry.
The art of Syd Mead, Sparth (Nicolas Bouvier),  Rainart (Sebastien Larroude), Vyle (David Levy), John Wallin Liberto and other awesome concept artists will keep me inspired :)

I have already done BGE version of Simon Wallner's sky implementation originally from 2002 GDC Presentation by Naty Hoffman and Arcot J. Preetham. HERE is the link to implementation details and even a demo. It will take care of lighting and atmospheric effects:





..maybe I can finally finish a game I have started
I will screen cast the whole developing process from now on.

7DFPS

7DFPS - yeah I participated as a weapon and character 3D modeler in a group of skilled BlenderArtists. Although we did not finish the game in time, our project is still going on. I started late, I think in day 3. Here is some stuff I did for it:

SigSauer P226 (coincidentally the same gun team Wolfire made for their 7DFPS Receiver)
2570 tris
1024x1024 diffuse/spec maps







wire (red edges - UV seams)



team "swat" character w/o helmet
2720 tris
1024x1204 diffuse/spec maps

unlit






there is also an op-force character, but he is not yet done.

projected grid in vertex shader

I am in the middle of making a complete water/underwater shading system in GLSL. Water surface wave displacement is now the last thing to deal with and "projected grid" concept is something I wanted to try. You can read about it in this cool article HERE. But one thing I did not found is an approach to do it completely in a vertex shader, which might speed and simplify things a lot.

As an exercise I reinvented one myself.

What it does is scales the our grid to view frustum space coordinates and projects it to specified plane in the world.
The easy thing is that frustum-space (untransformed) coordinates for our water plane is already provided as gl_Vertex. The value range is between -1.0 to 1.0 and values outside of this range correspond to points which are not in viewing frustum.
So in X axis -1.0 is left and 1.0 is right edge of the screen, Y - upper and lower edge, but for Z -1.0 is near plane and 1.0 is far plane. The tricky part is that while X and Y values are linear, Z values are exponential - more densely packed at near plane.
Next part is to create a virtual plane to project our grid to. We only need the grid Z axis to be projected as X and Y are already at needed position - at screen edges. To do so, we need to create world position. I transformed texture coordinates of grid with camera transformation matrices and then with line-plane intersection I got the coordinates of ground plane. And finally we create a depth from ground position to apply to Z coordinate of the grid. As Z is exponential, I found THIS very useful to convert linear depth to exponential.

screenshots (not an eye candy yet):

wire:


filled:


clamped size:


with a displacement map:



There is yet a lot of work ahead, but I felt I should share this. Maybe someone finds this useful.

get the vertex shader HERE

edit: I found a technique by Eric Bruneton, which is much more useful easier and faster than mine, hehe. Still it was a nice exercise and I found out bunch of new stuff while doing this.