Sphere Map Node

Sphere Map accepts a 2D image with a strict 2:1 ratio. The X axis represents 0-360° of longitude, the Y axis represents -90° to +90° of latitude. This is the LatLong / equirectangular format, ubiquitous for environment HDRIs.

Advantage over ray tracing: much faster. A sphere map generates 360° reflections in real time with little loss of accuracy for distant environments.

• Effects Library: Tools > 3D > Texture > Sphere Map
• Quick add: right-click in the Node Editor → Add Tool > 3D > Texture > Sphere Map

The Sphere Map strictly expects a 2:1 ratio (width = 2× height). Typical resolutions:

• 2048×1024 - standard preview HDRI
• 4096×2048 - production quality HDRI
• 8192×4096 - high quality HDRI (fine reflections)
• 16384×8192 - ultra HDRI (rarely needed, expensive)

If the ratio is not exactly 2:1, Fusion clamps at the poles or at longitude 0° depending on the imbalance. Result: visible distortion.

Free HDRI sources: Poly Haven (polyhaven.com), HDRI Haven (its former name), HDRMaps. Use .exr or .hdr to keep the dynamic range.

• Image Input (orange) - required. 2D RGBA image in equirectangular format (2:1 LatLong). An .exr/.hdr HDRI is recommended for correct dynamic range in the reflections.

Classic workflow for a reflection map:

Loader (HDRI.exr) ──→ Sphere Map ──→ Reflect (Reflection Color) ──→ Shape 3D

For a skybox (visible environment):

Loader (HDRI.exr) ──→ Sphere Map ──→ Shape 3D Sphere (very large, camera inside) ──→ Merge 3D

Angular Mapping

Enables an improved version of the mapping that reduces squashing at the poles and better preserves the surface distribution on the sphere. Useful if your HDRI shows visible artifacts at the north/south poles.

Rotation

Rotates the HDRI around the axes. Essential to line up the environment with the other lights in the scene (e.g. match the HDRI sun with a Directional Light).

Texture Filtering Mode

• Nearest - fast, pixelated artifacts.
• Bilinear - standard.
• Trilinear - better for downscaling.
• Anisotropic - higher quality, perspective-aware. Recommended for the final render.
• SAT - summed area table, high quality, more memory hungry.

Material ID

Identifier for AOVs.

Sphere Map (this node)

Accepts 2:1 equirectangular - the ubiquitous HDRI format. Easier to find as a source. Can show subtle artifacts at the poles (reduced by Angular Mapping).

CubeMap

Accepts a cubic layout (6 faces or a cross). No artifacts at the poles. But a less common HDRI format - often used for video game skyboxes.

Rule: Sphere Map for downloaded HDRIs (LatLong is the most common format). CubeMap if you already have a skybox in a cubic layout.

• HDRI environment reflection - Poly Haven HDRI → Sphere Map → Reflect ← metal Cook Torrance. Realistic chrome or gold instantly.
• Exterior scene skybox - sky HDRI → Sphere Map → large inverted sphere (normals pointing inward) in the background.
• Studio HDRI (indoor lighting) - photo studio HDRI → Sphere Map → Reflect. The studio lights reflect in the material consistently.
• Pseudo GI - by using the HDRI as an environment map on a low-intensity Reflect, you get an approximation of global illumination (colored ambiance on the object).
• Time-lapse with an animated HDRI - animate Rotation Y to scroll a sky over the course of the day.
• Refraction for glass - Sphere Map on the Refraction Color input of a Reflect = the environment appears correctly distorted through the glass.

• An .exr HDRI is a must for photorealistic reflections. An 8-bit JPG/PNG loses the dynamic range of the sun / highlights.
• Angular Mapping if you see artifacts at the poles of your mapping. Most visible on spherical objects.
• Rotation Y to line up the sun - the HDRI orientation does not always match your scene. Rotate Y until the HDRI sun lines up with your directional light.
• Anisotropic filtering by default for the final render. Bilinear for a quick preview.
• Strict 2:1 ratio - if you have a 3:1 or other panoramic HDRI, recrop or reformat it before import, otherwise you get distortion at the poles.
• For a custom studio HDRI, shoot with a panoramic head + stitching software (Hugin, PTGui) to produce your own LatLong.