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Tempest Ocean turns the reusable SpectralOceanSimulation into a cinematic stormfront without moving its scene policy into the simulation primitive. A seeded Phillips spectrum evolves height and horizontal displacement in frequency space, three normalized inverse GPUFFT2D transforms produce periodic spatial fields, and one assembly pass derives surface normals and temporally retained Jacobian whitecaps.

The example binds the simulation's two stable storage buffers directly to its ocean Model. The first buffer contains row-major (dx, height, dz, 0) records; the second contains unit (normal.xyz, foam) records. The vertex shader bilinearly samples those records to physically displace a tiled raster grid, while the fragment shader consumes the same normals and foam for Fresnel reflection, low-angle sunlight, crest color, and readable whitecaps. No wave-evolution shader is duplicated in the example, and no CPU readback sits between simulation and rendering.

The simulation and render tessellation are deliberately independent. The default frequency field is 128 × 128, while each displayed patch uses a 145 × 145 vertex grid. Renderers can therefore trade geometric smoothness against raster cost without reallocating the FFT field, and simulation quality can change without dictating the consumer's mesh topology. A centered three-by-three tile draw repeats the periodic patch; distance fog merges the outer tiles into the procedural horizon before their boundary can become visible.

Every frame records the simulation before the sky and ocean draws on the animation loop's caller-owned command encoder. Submission still happens once after the complete frame. The simulation owns its spectra, FFT scratch, spatial fields, and output buffers; the example owns the grid model, camera, floating-point scene target, depth attachment, bloom, and tone mapping. This is the same ownership split an application can use to mix the ocean into a larger scene.

The beauty target remains linear rgba16float. A procedural storm ceiling frames a low HDR sunbreak, the water reflects that sky, and narrow sun glints plus foam crests exceed SDR white before bloom and filmic mapping. Compatible displays request an extended-range Display P3 WebGPU canvas; standard displays receive the same floating-point scene through tone mapping.

  • Drag to orbit and use the wheel or trackpad to zoom. Pitch and distance clamps keep the eye above the largest authored crests and inside the fogged tile field.
  • Press C to toggle the slow cinematic orbit without changing wave state.
  • Press P or Space to pause or resume the absolute simulation clock. Paused frames continue to encode the same time with zero foam-decay delta, so the GPU output is stable.
  • Press R to restore camera, absolute wave time, playback state, and foam history. The seeded initial spectrum makes the reset deterministic.

What to inspect

  • Track individual large swells: their vertices move in X, Y, and Z rather than only perturbing a flat normal map.
  • Look across the low sun for narrow HDR glints and moving whitecaps that follow compressed wave regions instead of a scrolling foam texture.
  • Orbit toward the darker storm side and confirm that the same water material responds to a very different section of the procedural sky.
  • Zoom toward the surface and verify that the bilinearly sampled render grid remains smooth even though its resolution differs from the FFT field.