Spherical
The Spherical projection is typically used for environment textures and IES light distributions but can be appropriate for objects with an overall spherical shape. It performs latitude-longitude mapping for the U and V coordinates. When used with procedural textures, the W coordinate is the distance from the origin. In figure 1, the Spherical projection is used for the environment HDRI (courtesy of PolyHaven) and the sphere primitive in the scene.
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Figure 1: The Spherical projection used with the Checks procedural texture and HDRI background
When using an image texture to light a scene with the OctaneRender® Texture Environment node, spherical mapping combined with a Transform node provides the ability to rotate and translate the environment sphere's texture. To rotate a texture image (e.g., an HDR image) around its vertical axis, use the R.Y parameter in the Spherical projection node parameters (figure 2). The Use Rest Attribute option keeps texture maps from distorting when the geometry is animated.
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Figure 2: Rotating an HDRI environment texture map