Chart Type for 3D Spatial Data. Keywords: 3d, spatial, immersive, terrain, molecular, volumetric, point-cloud. Best Chart: 3D Scatter / Surface Plot. Secondary Options: Volumetric Rendering, Point Cloud. When to Use: Scientific/engineering context where Z-axis carries essential info not expressible in 2D. When NOT to Use: 2D projection conveys the same insight; mobile context; accessibility-required environments; standard business dashboards. Data Volume Threshold: WebGL required. Deck.gl: up to 1M points. Three.js: LOD required beyond 50,000 pts. Color Guidance: Depth cues: lighting and shading. Z-axis: color gradient (cool → warm). Transparent overlapping: opacity 0.4. Accessibility: D — 3D spatial charts are fundamentally inaccessible. Must not be used as primary chart type in any product UI.. A11y Fallback: Mandatory 2D projection view + data table; do not use as primary chart type in product UI. Library: Three.js, Deck.gl, Plotly 3D. Interactive Level: Rotate + Zoom + VR.