188.8.131.52 Some media concepts
Media can be global to the whole universe, or it can be contained by an object. In the latter case the media is
defined in the
interior block of the object definition.
For an object to be able to contain media (or to allow media from other objects or the global media inside itself)
it has to be defined as
hollow (a common mistake is to forget adding this keyword). If an object with no
media should not allow media inside itself (eg. a solid glass ball), then
hollow should not be defined
for that object.
If media is defined in the
interior of an object or as a global media it will have a constant density
throughout the object/universe. However, a density pattern can be specified for non-uniform media. Also all kinds of
transformations can be applied to the media. This is specially useful for various effects (such as smoke with certain