Invisible / Transparent Mesh Which Still Casts Shadows?

[Didact2401]

Is such a thing possible? Anyone know where I could possibly start?

[Nico coiN]

I'd say yes, but I'm not an expert at 3D modeling. Your mesh must be a closed volume, with no gap or seethrough. Just design it as usual, with proper flags to emit/reflect light/shadow, then just flip faces in Nifskope. Some advanced users such as Jonwd7, neomonkeus, Hana or MadCat221 may confirm or invalidate this trick.

[Jon]

Flipped faces will still show you the insides of a volume even if it is a closed convex one.   You are just now peering through the front of the object into the insides.  For example:

 

 

 

At the moment I'm not sure if it's possible to tell a NIF to only show up in the shadow scenegraph / render pass and be culled from the visible one.

 

I can say that alpha blending immediately removes the mesh from the shadow pass.   So translucency is never able to cast shadows.   Complete invisibility is different though and I can't think of any way right now to do it.