Hi,
Common interface for loaders was discussed a time ago, but discussion end up with nothing (OK, not really, but with the point that it is too complicated to find common points for most of the formats, especially ones that support animations etc., because of animation is defined and controlled format-specific way, and callers want to control animation etc. etc. etc.).
My suggestion is that you search through older (really older - maybe 1-1.5 years ago) posts in this forum, and we may give “loader standartization” effort another try - why not? at my opinion, at least static model loading can be standartized at least on very high level (like "Node loadFromResource(…)).
Yuri