Will weapon meshes/textures intended for fallout 3 and the like "drop in" to the NV Geck without problems?

As far as I know NV uses the same compressions and format as Fo3, and the nifs should work as well. So, yes.

Don't forget if you want to use weapons intended for FO3, you might want to add/position a SightingNode within Nifskope to make use of the new iron sight feature within FONV.

Would that apply to scoped sniper rifles?

No, scoped weapons do not use iron sight aiming obviously. However, you may need to change which .NIF file is used for the weapon's scope within the GECK. Some weapon mods use custom scope models. I also think that the default sniper rifle scope is different between FO3 and FONV.

The NIF file format has changed between Fo3 and FNV, there are two new nodes available (one is iron sights), so I don't think Fo3 weapons will work in FNV, but you can port them over and try of course.

In general, static NIFs and such work fine, but weapons were changed and this will cause you issues in-game (as mentioned, iron-sights and one other). JES had the following to say about adding the new node:

"The node is usually parented to anything that doesn't animate (e.g. the stock). It's used purely for positioning the camera correctly relative to the weapon's geometry so you shoot where you expect to shoot. If you want to get a head start, it's called ##sightingnode "

Another comment from the forums on it:

"If you want to create weapons that use iron sights, you must create a node in the weapon that lines up with the sights. Only the position matters; the orientation is always relative to the camera facing. This means the line between the iron sights camera node, rear sights, and front sights must all be parallel to one of the axes (X?) in your 3D modeling program of choice."

Luck,

Miax

Besides iron-sights, what is the other issue/difference between FO3 and FONV weapons Miaximus?

I should also mention I don't think that the ##sightingnode is actually required for weapons to function in FONV. I think if you don't include one with the .NIF, the weapon will simply work like the weapons in FO3... by zooming in on the HUD reticule or something.

I'm curious about setting up the ##sightingnode though. How can you ensure that the position you place it in will result in an "accurate" sighting system? Does it have to be lined up with the ProjectileNode perhaps? And what happens if you position it far away from the weapon.... like to the side or something?