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Wind Dynamics & Solvers
The WIND tab governs the physical simulation behavior of your assets. Dynamic Wind Studio provides three distinct runtime tiers, motion presets, and interactive live viewport preview.
1. Asset Type Presets
Choose an asset preset to instantly configure default bending stiffness, turbulence response, and damping curves:
- Tree: Multi-tier hierarchy with rigid root, flexible trunk bending, and leaf flutter.
- Bush / Shrub: Radial outward sway with ground-level stiffness clamping.
- Ground Cover / Grass: High-frequency micro-flutter with clump phase dispersion.
- Hanging Banner / Flag: Single or top-pinned fabric motion with aerodynamic edge-on drag.
- Two-Pinned Cable / Rope: Catenary curve rig pinned at both ends with tension preservation.
- Interactive Prop: Custom physics rigging for street signs, hanging lanterns, and market stalls.
2. Runtime Tiers
Dynamic Wind Studio features three scalable simulation architectures:
1. GPU Tier (Epic Games Dynamic Wind)
- Technology: Hardware-accelerated vertex deformation driven by Unreal Engine's experimental GPU Dynamic Wind system.
- Best For: Massive open-world forests, expansive grass fields, and dense foliage biomes.
- Performance: Near-zero CPU overhead; evaluates in compute shaders alongside Nanite streaming geometry.
- Simulation Groups: Assign parts to GPU groups (Trunk, Branches, Leaves) to define group influence curves and gust attenuation.
2. CPU Procedural Tier
- Technology: Lightweight algorithmic wind simulation running on CPU threads.
- Best For: Mobile platforms, stylized games, or medium-range background assets.
- Character Push (deg): Deforms branches and foliage outward when gameplay characters walk through meshes.
3. CPU Physics Tier
- Technology: Full spring-damper physical simulation engine.
- Physics Parameters:
- Wind Drag & Edge-on Drag: Aerodynamic resistance forces applied across triangle surfaces.
- Flutter (Frequency & Wavelength): High-speed fabric and leaf turbulence oscillations.
- Cloth Links (Stiffness & Range): Constrains adjacent bone chains to behave like continuous fabric.
- Weld Touching Tips: Bonds overlapping cable or foliage ends.
- Character Collision: True capsule and mesh collision with interactive character push forces.
3. Interactive Viewport Wind Preview
Test and validate your wind dynamics directly inside the Studio viewport before committing to build:
- Simulate Wind: Starts real-time physics and wind animation in the viewport.
- Wind Speed (km/h): Tests gentle breezes (10 km/h) up to hurricane forces (120+ km/h).
- Direction (Yaw): 360-degree interactive wind direction compass.
- Gust Intensity & Turbulence: Simulates irregular gusts and multi-octave turbulence noise.