Infinite explorable underwater world created using Rust and WGPU using marching cubes and 3D perlin noise populated with 3D boids.

• Running live on the web at: https://lelserslasers.itch.io/underwater-world
• Showcase video: https://www.youtube.com/watch?v=heCIgXLkNO0

• Change pitch: WASD or arrow keys
• Roll: Q/E or pgUp/pgDown
• Speed up: space
• Slow down: control
• Reset submarine: R or enter

The main build target was WASM and WebGL, meaning I did not have access to any parallelism/threading or compute shaders. This made performance a key concern, especially with the generation of the world/chunks and the fish.

• Performance optimizations
  • Chunks/World
    • Each chunk is built one at a time and is split over multiple frames to keep the frame rate high
    • To hide the chunk generation, the chunks to build are sorted:
      1. If they are in the view frustum
      2. If they are in the direction that the sub is facing
      3. Distance to sub but with a little extra prio to chunks with a lower Z value (because they are more likely to be not blank)
    • After collecting the perlin noise values for a chunk, if the chunk will be blank, it skips trying to create the mesh and it will skipped for rendering
    • Built chunk models are stored and sent to the GPU in a more compact way using index buffers
    • Despite the fact that chunks take up 16x16x16 voxels, they are built out of 12x12x12 voxels
    • When trying to render the chunks, it will only sent chunks that in the view frustum to the GPU
    • vertex order is designed for backface culling
  • Boids
    • Index buffer + backface culling for models
    • Spatial partitioning used to find boids that are close to each other instead of iterating through all boids
    • If boids get too far from a point, they are teleported to the opposite side
      • The center point is a space in the direction the sub is facing, as there is no point in having the boids be far away from the sub or behind the sub
• Other features
  • Marching cubes with linear interpolation based on the isosurface values
  • 3D multi-octave perlin noise to generate infinite terrain
  • Boids
    • Wall avoidance using raycasting
  • Shader effects:
    • Fog: further away objects fade into the sea
    • Darker/deeper: the deeper you go, the darker the fog/water color gets
    • The fish have a swimming animation that moves some of their vertices left and right using a sine wave
    • The sub has a light that illuminates the direction it is facing

• Submarine: antonmoek - https://www.cgtrader.com/free-3d-models/vehicle/other/low-poly-cartoon-submarine
• Red fish: 3DRPolyFactory - https://www.cgtrader.com/free-3d-models/animals/fish/fish3d-v1
• Green fish: 3DRPolyFactory - https://www.cgtrader.com/free-3d-models/animals/fish/fish-3d-6a34c6e0-dff2-4375-9257-469577d423cd
• Blue fish: 3DRPolyFactory - https://www.cgtrader.com/free-3d-models/animals/fish/bluegill-886e1016-26b4-49c2-a594-799da26c1ce7
• Favicon: Smashicons - https://www.flaticon.com/free-icon/submarine_2739364?term=submarine&page=1&position=22&origin=tag&related_id=2739364

• https://sotrh.github.io/learn-wgpu/
• Marching Cubes/World Generation
  • https://www.youtube.com/watch?v=M3iI2l0ltbE
  • https://paulbourke.net/geometry/polygonise/
  • https://developer.nvidia.com/gpugems/gpugems3/part-i-geometry/chapter-1-generating-complex-procedural-terrains-using-gpu
  • https://people.eecs.berkeley.edu/~jrs/meshpapers/LorensenCline.pdf
  • https://www.youtube.com/watch?v=YyVAaJqYAfE
  • https://www.youtube.com/watch?v=TZFv493D7jo
  • https://www.youtube.com/watch?v=4O0_-1NaWnY
  • https://www.youtube.com/playlist?list=PLFt_AvWsXl0eBW2EiBtl_sxmDtSgZBxB3
• Boids
  • https://stackoverflow.com/questions/9600801/evenly-distributing-n-points-on-a-sphere/44164075#44164075
  • https://www.youtube.com/watch?v=bqtqltqcQhw
  • https://natureofcode.com/book/chapter-6-autonomous-agents/
  • https://www.red3d.com/cwr/boids/
  • https://www.youtube.com/watch?v=gpc7u3331oQ
  • https://eater.net/boids
  • https://github.com/miorsoft/VB6-3D-Flocking-Boids
  • https://github.com/albertomelladoc/Fish-Animation/blob/master/FishAnimation.shader
• Techniques from old projects:
  • https://lelserslasers.itch.io/boids
  • https://lelserslasers.itch.io/3d-cellular-automata-wgpu-rust
  • https://lelserslasers.itch.io/minecraft