The Spherical projection is used for Environment textures and IESAn IES light is the lighting information representing the real-world lighting values for specific light fixtures. For more information, visit http://www.ies.org/lighting/. light distributions. 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 (Figure 1).
Figure 1: The Spherical projection used with the Checks procedural texture
When using an Image texture to light a scene with the OctaneRender® Environment node, spherical mapping combined with a Transforms node lets you rotate and translate the environment sphere's texture.
To rotate a texture image (e.g., an HDR image) around a vertical axis, switch the texture environment image's projection to Spherical and rotate it via the Y axis through the Sphere Transformation sliders.
Figure 2: Spherical projection applied to a box, cylinder, and sphere