Nishita Atmospheric Scattering

Instead of low-fidelity texture skyboxes, RayTrophi simulates light transport inside a multi-layered atmospheric dome using Rayleigh scattering (simulating small nitrogen/oxygen particles) and Mie scattering (dust and water particles). It also solves the Chappuis absorption bands for Ozone, producing deep blues during golden hours.

struct NishitaSkySettings {
    float sun_elevation;     // Sun position above horizon (-10 to 90 degrees)
    float air_density;       // Rayleigh scattering coefficient scale
    float dust_density;      // Mie scattering coefficient scale
    float ozone_density;     // Ozone absorption scaling (Chappuis bands)
    bool sync_sun_light;     // Synchronize sun direction with directional lights
};

FFT Ocean (Tessendorf's Algorithm)

Deep ocean waves are computed by resolving the Phillips wind spectrum inside frequency space using GPU FFTs. The generated heightfield deforms the ocean mesh, while a displacement Jacobian calculates local foam accumulation based on wave crest convergence.

struct FFTOceanSettings {
    int fft_resolution;      // Resolution grid size (64, 128, 256, 512)
    float wind_speed;        // Wind speed affecting Phillips spectrum amplitude
    float wind_dir_angle;    // Direction angle (radians)
    float choppiness;        // Horizontal displacement Jacobian factor
    float wave_amplitude;    // Amplitude scaling for height mapping
};

Procedural Generators

Thermal & Hydraulic Solvers

Thermal erosion calculates slope collapse by moving soil to neighboring cells if the local slope angle exceeds the Talus angle limit. Hydraulic erosion simulates water droplets carrying soil sediment down slope paths, carving drainage basins over iterations.

Modeling Operations

Interactive Brush Falloff Editor

Modify the brush profile curve. The lookup table adjusts the displacement strength of vertices depending on distance from brush center.

Wet Oil Smudge Modeling

The paint engine simulates fluid paint transport on vertices, allowing active brush strokes to smudge and mix with underlying wet color layers based on viscosity and pigment accumulation settings.

Marschner BSDF Theory

Instead of simple shading, RayTrophi simulates light refracting through translucent cylinder fibers. The shader computes the **R (reflection)** lobe, **TT (transmission-transmission)** lobe, and the **TRT (transmission-reflection-transmission)** lobe to render realistic secondary highlights.

struct MarschnerHairMaterial {
    float melanin_concentration; // Melanin pigment level (0.0 to 1.0)
    float hair_roughness;       // Specular highlights width
    float specular_shift;       // Highlights offset angle (scales offset)
    float hair_ior;              // Refractive Index (Default: 1.55)
};

AnimGraph State Machines

Skeletal joint transforms are calculated by evaluating a visual state machine graph. Nodes blend animation clips using speed sliders or boolean states, outputting skeletal bone transformations.

Hardware Raytracing Platforms

NVIDIA OptiX (GPU): Leverages NVIDIA RT Cores for BVH traversal and ray intersection. Integrates CUDA denoisers for high quality.

Vulkan Ray Tracing (GPU): Uses cross-vendor hardware pipelines with dynamic Top-Level Acceleration Structures (TLAS) updates for dynamic scene objects.

Intel Embree (CPU): SSE/AVX vector-aligned CPU ray-traversal for systems without dedicated GPU ray-tracing cards.

HUD Diagnostics Overlay

Real-time analytics computed directly from the converged frame buffer:

Shortcuts Reference