Hey Timmiegun, had a look, simple fix. :)

As far as I can tell most (all?) of your scenery/decorations don't have normals[www.scratchapixel.com] set. This is absolutely fine and most of the scenery in vanilla also don't have normal data.

However, it's imperative that meshes with and without normals do not get put together in the same VOCollections - this is what causes the black objects you've encountered.

The fix is simple enough - make sure every object has the right voCollection tag.

The voCollection tags are not self-sorting, they require the creator to divide their models among VO collections intelligently.

How to fix - short version
In amazing_mangroves_plants_disc1.data for any models which do not have normals (all?) change:

"voCollection":"scenery2", --------> "voCollection":"scenery2-no-normals",

If any models do have normals, then they should be called "scenery2" or similar (without the -no-normals bit).

Long version
That's the short version and should fix your issue. However, I'm never really explained how it works so here's a quick rundown of good voCollection tagging practices for future use of all modders:

When assigning voCollections:

1. Normals and non-normals must be kept separate.
2. Models which have different shadowDetailLevel must be kept separate.*

Originally posted by shadow detail level explanation:

*Shadow detail level determines the shadow quality level that the shadows are enabled or disabled:
0 - no shadows
1 - only shadows on high settings
2 - only shadows on high or normal settings
3 - only shadows on high or normal or low settings

Basically, the more important shadows are to the object, the higher the number you should give it.

OK, on to naming conventions. Just to be clear, these are just tags which divide up the models among VOCollections, the names are not analysed so they can be anything you want.

In vanilla I use the following naming convention. The scenery vo collections are named like this:

scenery{shadow detail level}{optional no normals tag}

e.g.

"scenery2-no-normals" - Is for objects with shadow detail level 2 and no normals
"scenery1" - is for objects with shadow detail level 1 and with normals

Whereas the tanks are all just given the vocollection "tanks" because all of them have normals. Same with "equipment".

If you did design a tank or equipment without normals then it would have to be split into a separate VOCollection called something like "tanks-no-normals".

EDIT: pinned this thread in case anybody runs into the same issue in the future.