I've created a Seasons product but I've run into some limitations that end users were quick to pickup on and express their feedback. As I understand it, there is a planned "Seasons" update due out sometime in 2022 (great news).
I investigated using Polygon Objects as a means to control vegetation but soon realized that this is not a good approach to controlling vegetation for the entire planet. So I abandoned that route as it was going to accomplish my goals.
So I explored "Simple Biome" SDK process and discovered (mostly trial and error) this was the way forward to making world vegetation changes/enhancements.
I'll go over some of the limitations I've ran into (and user feedback) and my suggestions on how to open up the vegetation support via the SDK:
The files I've been working with for my community install are:
*_biomes.xml *_biomes_cities.xml *_species.xml
1. 17 Species supported, 3 of the 17 species don't render correctly in sim (Vineyard, orangetree, olivretree) ... fyi, spelling issue on "olivretree" should be "olivetree".
2. In the Species.xml file for Material name I'm unable to specify my own textures (seems to be hard coded to 17 materials/textures only)
3. For an EcoRegion defined only in the Biomes.xml file for a single BiomeRule, the sim will still use the Biomes_cities.xml entry for the BiomeRule even though the EcoRegion is NOT listed in the BiomeRule in Biomes_cities.xml?
4. Biomes_cities.xml will override Biomes.xml if an EcoRegion is listed in both files.
5. No ability to modify the leaf/flower colors separate from the tree branches
6. No ability to have leafless trees except "orangetree" or "olivretree" that renders some what leafless
7. There is no nothern/southern hemisphere support, BiomeRules are keyed based on EcoRegion within the sim. So it's not possible to show brown leaf winter trees in Southern hemisphere in July vs. green leaf summer trees in Northern hemisphere in July. Since Eco Regions do cross North/South hemispheres it wouldn't make sense to base a BiomeRule on an EcoRegion entry without ability to delineate North and South.
8. No ability to have vegetation changes (from the XML files) be reflected immediately in sim. I have to be at the main menu, make the changes to the XML files, then create or load a saved flight in order to see my vegetation changes.
9. vineyard material doesn't render correctly:
10. orangetree and olivretree render the same and leafless:
There are 391,000 or more vegetation species, unfortunately only 14 are being represented.
Since "Seasons" is on the MSFS roadmap for sometime 2022, and I don't know exactly what changes will be made to the vegetation XML files or if they will even persist, I thought I could add my request for SDK addition/enhancement in order to meet end user requirements:
1. Provide a vegetation material specification (i.e. a Photoshop, Blender, Substance, 3DSMax file) and allow us to create our own material and ability to reference that material in Species.xml and in our deployment package.
2. As part of the species vegetation file specification, add the following attributes (in the Species.xml):
a. Leafless (Yes/No)
b. Flowered (Yes/No)
c. Branch Color (RGB)
d. Leaf Color (RGB)
e. Flowered Color (RGB)
3. Add an Attribute to EcoRegion to identify Hemisphere (Northern/Southern) so when aircraft geo coordinates are in Northern hemisphere the EcoRegion with Northern attribute is used to determine which BiomeRule which can then have vegetation colors set appropriately and would allow for realistic transitions of flights from North to South and visa-versa.
4. In my Seasons product, I use RESOLVE EcoRegion data (846 regions) to map to BiomeRules which is a more current/accurate representation of the Biomes than default MSFS. However, there is far more accurate Level IV Eco Region data available which would help increase the accuracy of vegetation types and locations. Per SDK documentation we currently have no access to CGL for Biome information (which is where I assume the geo coordinate data would be defined for Eco Regions).
5. Add ability to "reload" vegetation (biomes.xml, species.xml, biomes_cities.xml) while in a flight in sim (make available a simple SimConnect command to refresh/reload).
Unfortunately I don't have access to the latest (300 person cap) MSFS Beta even though I was on the original MSFS Beta going back to Oct 2019, so I'm unable to see what changes might be happening to vegetation files and/or be able to provide feedback on those changes based on my experience and from my user feedback.
I think my Seaons product which includes my Seasons generator based on real world Eco Region data is certainly a benefit for MSFS and I would love to see some of these restrictions addressed or be able to help.
MS/Asobo feel free to PM me or contact me via firstname.lastname@example.org and I'd be happy to provide input and/or answer questions and ability to use my product so you can see some of issues I've run into and how to potentially solve them.