Tree Generation (Late 2020)

This is a post dedicated to issues relating to generation of "tree" structures in custom biomes, as well as potential fixes for common problems. I want to avoid rehashing any previous bugs/solutions but at the same time it is late 2020 with no resolution or recent forum topics in sight.

Common Issues with Fixes:

- Trees are spawning underwater/in the air | Setting the "restrict to block type" for custom structures to a custom grass block or default grass block will prevent this from happening.

   * Despite this, some trees with shorter height will spawn within hills/into grass blocks, a potential fix would be to introduce an override option for leaf blocks to not replace ground blocks.

   * Some trees will technically spawn on grass blocks, but the stump will still float over air (usually messy hill generation), I am still unsure if structure block placement is important here as I've put the structure block directly underneath the stump, thinking it would spawn in place of the structure block.

- Trees are spawning within each other, this is frequent when group sizes per chunk are increased, the spread of trees is also quite strange; rather than spawning equal distance apart, the world generator spawns them in clusters, resulting in this bug. I highly doubt this is a fixable issue as it messes with world generation

Suggestions for Future Updates

- Adding different vanilla tree schematics as options for *custom tree blocks* / current default is the base oak/birch tree schematic.

- Migrating a custom schematic option into the biome tab, allowing for custom schematics instead of "custom blocks" option. In addition, support for multiple structures at once would        be great.

   * I am not accepting a "just add another structure element" as this doesn't strike me as efficient, I don't entirely know how vanilla biomes are coded but I doubt they have individual trees as generated structures per 1 million blocks, and I think this structure element being cranked to maximum is making the world generation a lot more buggy.

- For "custom block" trees, a "max stem height" option would also work well with the "min. stem height" option already implemented.

- Removing the requirement to specify custom "vines" and "fruits" blocks.

If you made it this far, thanks  for reading! I am totally open to a discussion/brainstorming on these issues!