The initial VRML/X3D node that created this cache record. This is only the first node, that initiated this TTextureImageCache item. Note that many TAbstractTexture2DNode nodes may correspond to a single TTextureImageCache (since TTextureImageCache only tries to share GLName between them). So this may help during _IncReference, but nothing more — it's *not* an exhaustive list of texture nodes related to this video texture!