map projections

These are all map projections used to transform a 3D scene (like the Earth or a 360° photo sphere) onto a 2D surface. Here’s how they differ:

  1. Cylindrical Projection • How it works: Imagine wrapping a cylinder around a sphere (like the Earth or a 360° image), then unrolling it into a flat rectangle. • Coverage: Captures 360° horizontally, limited vertically (usually less than 180°). • Distortion: Increases toward the top and bottom (poles look stretched). • Use case: Standard panoramic images; equirectangular photos (often used for 360° video). • Appearance: Straight horizontal lines stay straight; vertical lines may bow.

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  1. Spherical Projection • How it works: Treats the entire view as a complete sphere (360° x 180°). No flattening—it’s meant for interactive viewing where the user “looks around” inside the sphere. • Coverage: Full 360° x 180° (all directions). • Distortion: Not shown unless flattened; usually experienced inside a viewer (VR headset, phone, etc.). • Use case: 360° photography, VR environments. • Appearance: No visible distortion when viewed interactively, but extreme when flattened to 2D.

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  1. Mercator Projection • How it works: A special type of cylindrical projection used in cartography. Great for preserving angles and shapes near the equator but distorts scale at the poles. • Coverage: Often limited to about 85° N/S latitude due to severe distortion at the poles. • Distortion: Shapes are preserved locally, but areas get massively distorted (e.g., Greenland looks the same size as Africa). • Use case: Web maps (like Google Maps), marine navigation. • Appearance: Recognizable by its familiar “rectangular” world map look.

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Quick Visual Metaphor: • Cylindrical: Like peeling a label off a can and laying it flat. • Spherical: You’re inside the sphere, looking around. • Mercator: Like stretching the can label so everything looks rectangular, even near the top/bottom.

Want a side-by-side image to see the difference visually?