Team Member: Narek Daduryan | 305 391 327 | narekdaduryan@gmail.com
You are a lone bird tired of your hometown and decide to head for adventure. You fly with other fellow birds as you explore the world!
In the past I had created a boids simulation in 2D. I plan to extend this to 3D, and include a continuous globe over which the birds can fly and explore. You will control one of the birds as others fly around and with you.
Will use basic shading, transformations, matrices, and cameras to build a world and place many birds on the scene. Will use emergent behavior (boids) to control autonomous birds, which relies on vector and matrix mathematics.
You are able to control your bird in third-person, and watch as the other boids interact with you. I implemented a player-controller that allows you to orbit around a small globe.
Player Controls
W A S D - Move Bird
R - Toggle Camera View
I used the basic Boid framework (cohesion, separation, alignment) as a baseline. This formulation suffers from all boids converging to one flock over time. I used a few additions to help overcome this. I added slight randomness to each boid's preferences (cohesion, separation, and alignment coefficients). I also added "break aways" where each boid has a small chance to want to break away from the flock and go in a separate direction. This helps keep a good mix of big and small flocks. Lastly, I added obstacle avoidance by adding collision detection : I check each boid's trajectory with the terrain, and if it collides, I add a strong opposing force.
The game uses primitive objects and .obj objects to draw the globe, birds, and trees. Each is shaded using phong or textured phong shaders. I implemented fog to add a sense of depth to the scene.
There are also two camera views : You can either view your bird in third person, or zoom out to view the globe to better see the action going on.
I used a custom terrain shader to add a stylized look to the terrain. The shader uses the height of each vertex above the origin to determine the materia – sand, grass, or snow, and also uses the vertex's normal to determine if it should be a rocky material.
I implemented a stylized water shader to make the water look nicer. The water shader has waves using animation time. I also implemented a water-depth-based water shading. To enable this, I first render the globe terrain's height to a frame buffer. Then, I sample the terrain height in the water shader to determine the water depth. I then add some white ripples when the water is shallow, and make the water darker when it's deeper.
I also added a simple animation to the bird's wings. When diving, the wings stay flat. During normal flying, they flap, and when ascending quickly, they flap faster.
I also implemented a skybox for my world. To do this, I used a 6-sided cubemap and rendered it in clip-space based on the camera view angle.
Further optimization is needed to make the game more performant. Currently, I am able to simulate about 300 boids in the world, with low-accuracy collision detection.
The collision detection takes a long time, since it is run on the CPU rather than GPU, and checks each boid with each triangle of the terrain. As an optimization, I batched the collision detection, so each frame, only ~5 birds check their collision. On average, each bird gets it collision checked every 60 frames.
I also added basic culling for birds and trees to not draw them if they are on other side of the globe.
As an optimization, it would be best to add some spatial map (quadtree or hashmap, etc) for the boid calculations, so boids can quickly index nearby boids when doing calculations. Moving the collision detection to a compute shader would also be a large speedup.
Sebastian Lague Coding Adventures (eg Link 1, Link 2)
My own 2D boid implementation (Link)
Boids Reference & Enhancements (Stanford, U-Turns)
WebGl references (Skybox, Buffers)
Stylized Water Shader Ideas (Link)
Low Poly Bird Object: (Link)
Low Poly Trees Pack (Link)
This project is tested with Browserstack.