Указатель источника текстуры. Т.е. в этой строке указывается то, что будет служить текстурой для шейпа.
NiSourceTexture represents all texture image objects that are created from either an image file or a block of in-memory pixel data. This class is the NiTexture subclass that applications will use most frequently (many applications will use it exclusively), either directly or via content imported from NIF files. NiSourceTexture objects represent both static and dynamic content, as NiSourceTexture data objects can have their pixel data modified on the fly to implement dynamic texture behavior.
