What is an Environment Sphere?
This Poser prop is a very large sphere with a radius of 750 Poser feet. This radius was chosen to be very large, but not too large, because the Poser cameras are set up by default to stop rendering objects that are more than 860 feet from the center of the scene. This can be changed, but I didn't want you to have to deal with that. For most uses, a 1500 foot diameter environment sphere is going to work just fine.
Because the sphere is so huge, pretty much wherever you put your camera, it will be inside the sphere, and that is the objective. The sphere is a stand-in for the rest of the universe. It will provide something to see in all directions. Most important, it will provide something to reflect in all directions!
Since the Poser introduction of Indirect Diffuse Light (IDL) you can also use the environment sphere as a major light source, or even as your only light source!
The environment sphere is not meant to be viewed from outside. What this means is that the polygons of the sphere are facing inwards, directly the opposite to most spheres you've encountered before. Do not shrink this sphere and try to use it as a ball of some sort. It will look very strange.
The environment sphere is designed to support the direct use of photographs in equirectangular spherical panoramic format. A spherical panorama records the scene around the photographer in every possible direction - 360 degrees horizontally and 180 degrees vertically. The particular UV mapping style called equirectangular is very common and you should be able to find lots of tools that can make this format, and lots of images that already are in this format.
Sometimes you don't want or need the bottom half of the image. For these cases, use the EnvHemisphere prop. This is the same but only includes the upper half of the sphere.
Sometimes you find a panoramic image that doesn't even have the lower half (ground) in it - just the upper half (sky). For these, use the EnvDome prop. This is the same geometry as the EnvHemisphere, but the UV mapping is adjusted for a half-height image. In other words, the EnvHemisphere uses half the image, the EnvDome uses the whole image. (A whole half is not the same as half a whole. LOL You heard that here first.)
Download the zip file - EnvSphere.zip. It contains a standard runtime structure. Within it there are some props and some materials. Unzip these either to one of your existing runtimes, or into its own runtime.
Click here to download: EnvSphere.zip
The sub-pages below provide more information. Please visit them.