Support grouping or applying variants for composite/structure entries

[StarliteHeart]

Describe the Addition

I'd like to ask if it'd be possible to include an option to group multiple composite-style entries into variant-like entries.

Screenshots and Videos

No response

Additional Context

The main purpose would be for compacting entries down where multiple mods may introduce a lot of overlapping types of trees or other structures.

One desired use case for composite variants is the option to simplify pages for structures that are simply variants of one another. For instance, both Biomes O' Plenty and Mystic's Biomes add three different variations of maple tree. When proper composites are prepared for them, this can lead to six maple tree-related entries in the field guide, which could then be condensed further into two entries for the two different styles of maple tree, each in three colors.

Another use case is to group many similar styles of structure into a single type page or subcategory. Multiple mods all introduce their own styles of palm trees (e.g. BOP, Let's Do Beachparty, Crabber's Delight, etc.), and among dozens of tree entries, it may be fruitful to group them all by tree families, allowing variants to act more like subspecies to discover instead of as entirely new pages.

[malcolmriley]

I would like to second this suggestion.

While this can be accomplished with composite entries and redirects, for myself, the actual underlying desire here is "I would like to have a single guide entry with multiple different pictures".

Alternatively, if the composite entry system's render specification could be extended to allow for an array of separate images to render, (e.g. list of structure or entity definition with NBT) it would probably cover this as well as #121. In such a case, the variants system could probably be deprecated entirely.

[evanbones]

This is supported as of 1.10.0 using visual variants on composite entries: a single composite can hold multiple structures, each acting as a discoverable variant (with its own page tab and scanning).

Maple trees for example with two styles, three colors each, would be two composite files like this:

{
  "values": [
    {
      "id": "fieldguide:maple_tree_round",
      "display": "biomesoplenty:maple_sapling",
      "components": [
        "biomesoplenty:maple_log",
        "biomesoplenty:red_maple_leaves",
        "biomesoplenty:orange_maple_leaves",
        "biomesoplenty:yellow_maple_leaves"
      ],
      "visual_variants": [
        {
          "variant_id": "red",
          "display_name": "Red Maple",
          "structure_nbt": "biomesoplenty:red_maple_tree",
          "components": [
            "biomesoplenty:maple_log",
            "biomesoplenty:red_maple_leaves"
          ]
        },
        {
          "variant_id": "orange",
          "display_name": "Orange Maple",
          "structure_nbt": "biomesoplenty:orange_maple_tree",
          "components": [
            "biomesoplenty:maple_log",
            "biomesoplenty:orange_maple_leaves"
          ]
        },
        {
          "variant_id": "yellow",
          "display_name": "Yellow Maple",
          "structure_nbt": "biomesoplenty:yellow_maple_tree",
          "components": [
            "biomesoplenty:maple_log",
            "biomesoplenty:yellow_maple_leaves"
          ]
        }
      ]
    }
  ]
}

There's more details on this in the datapacks/advanced page of the wiki. Let me know if you run into any issues