water/underwater & sky shader update #03

Yep, I haven`t been very active blogger lately.
I am very glad that company I am working for brought me to Amsterdam to Blender Conference this year. I even did a presentation there together with my colleague Michael Otto about GLSL shaders in Blender Game Engine. And for the presentation purposes I decided to demo my water/underwater shader there.
Just before the presentation I managed to tune up the shader and the scenery a bit.




so the changes since last update are:
- projected grid approach for the water surface (lousy implementation)
- per-vertex displacement mapping for waves
- basic but effective shoreline detection for water surface and ground
- added some subtle cloud layer and stars in the skies

yet to be done:
- fixes on inconsistencies
- better and procedural wave propagation model
- focus to underwater visuals
- better camera transition from water/underwater
- better coastline behaviors
- buoyancy (partly done)
- heavy optimization
- when it`s done, as many have requested - implement in Unity

trees are generated with tree[d] by frecle

blend file to be uploaded (have to clean and optimize the code a bit)

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

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..

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"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)

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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.

BGE Candy status update 01

It has been a busy week with real life stuff, so I am not progressing very fast.

Last 2 days I have been working on environment reflection mapping coordinates. Blender currently have only view-space reflection coords reflect(viewvec,viewnormal);  and of course that is not nearly enough for a proper IBL (Image Based Lighting) setup.

So first I implemented world space reflection coordinates so the environment texture is world oriented.
Then I have implemented 2 most widely used mapping algorithms - "Angular" or "Sphere" mapping and "Equirectangular" or "Spherical Panorama" mapping but sometimes also called "Blinn/Newell Latitude-Longitude" mapping.
The third and most widely used one - "Cube mapping" should be already possible as a built-in function in OpenGL, but I have to figure out how to make it work in BGE.

Same mapping techniques can be applied not only on "Reflection" coordinates, but also on "Object" and "Normal" coordinates, which means that besides doing reflection and specular reflection, the environment mapping can also be used for texturing the object or doing image-based diffuse lighting.

these are the 3 environment map textures:

"sphere" or "angular" map

"equirectangular" or "spherical panorama" or "Blinn/Newell latitude-longitude" map

"cube" map

All 3 of them does the same job, but with different results. I found a nice article about all three of env-map approaches explained in detail HERE

I'm going to vacation for 2 weeks, so no BGE Candies till then..

BGE Candy branch

From now on I am a part of Blender developers team. Together with Matthew Dietel aka mokazon we started a new Blender development branch called "BGE Candy" with main goal to fix broken and add missing and new (mostly visual) features to Blender Game Engine.

I am quite excited about this, I even made our own logo and splash screen (with "sweet", "eye", "candy" and "Blender" in mind)



so here is the list of stuff currently done and yet to be done.

done:
• SSS (subsurface scattering) material
• rectangular area lights
• logic connector highlighting in UI

in progress:
• parallax mapping
• volumetric point & spot lights
• real-time composite nodes

planned:
• volumetric shadowing for volumetric lights
• environment cube-mapping
• scrolling texture coordinates in Blender material editor
• timer node in material node editor
• world normals in material node editor
• extra uniform inputs for 2D GLSL filters
• extra 2D GLSL filters
• Sky and Atmosphere
• fog volumes

BGE Candy branch thread in BlenderArtists HERE