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Placing Seasonal Trees around my custom airport

I am using P3D V5.3 with latest fixes. I have an ADE custom-built fictional airport and I would like to add seasonal HD trees around the perimeter, between hangers etc to make the airport look more realistic. I have ORBX TrueEarth GB installed with my ADE airport over laying this.
I understand that in order to have textures for 3D vegetation objects change with the seasons, one must use placement of scenery library objects via Autogen-XML-type *an.agn files created via FS / P3D Autogen SDK compiler. I have had a brief run through the SDK Autogen documentation and have an idea how to complete the models and groups using the AutogenConfigEditor/AutogenEditor. However I am lost on how I can use the Annotator as I don't have the PhotoReal Scenery for object placement. All I have is the ADE airport layout.
Can anyone point me in the right direction? I am currently using SIMDIRECTOR (which LM have finally got working really well) to place HD Trees around the airport which is really easy to do - BUT NO SEASONALITY! Current thoughts are to produce 3 gbl files (summer, fall and winter) and activate one depending on the actual season before I start P3D but it would be good to have autogen seasonality/

To use autogen object you need a photoreal scenery indeed. But for P3D v5 you can also get seasonal objects in normal library objects, by adding visibility conditions. Did you make the tree models yourself?

To use autogen object you need a photoreal scenery indeed. But for P3D v5 you can also get seasonal objects in normal library objects, by adding visibility conditions. Did you make the tree models yourself?
Hi arno - long time since we spoke. Have used P3DV4.4 format in Modelx converter to pick out the 5 seasonal variations of a tree models. Would plan to see how I can place this group around the airport.
Hi Arno. Found your post re specifying seasonal for the model and getting LUA when exporting the model from ModelConverterX.
Using the latest development ModelX I don't get a LUA file along with the .mdl file (like I did with the latest "PRODUCTION" version of ModelX.
When importing back in to ModelX I see the five textures and the model looks like all 5 applied (as the 5 textures are loaded). The reason for trying the
development version was because the .mdl output from the production version could not be loaded into latest Library Manager (gave reason that the .mdl file
was not valid).
Thinking that maybe the development version now also included the LUA in the model. I went ahead and put the .mdl file in a library using Library Manager and then used P3D V5.3 SIMDIRECTOR to select, successfully display - as summer version, and place the new "seasonal" tree on the perimeter of the airport. However, when I export the SIMDIRECTOR session to get an SXML and BGL file I only get the SXML with nothing in it. If I go back into SIMDIRECTOR and add a "normal" tree to the group and export, I do get the bgl and sxml files but they only contain the "normal" tree.
I think he issue is the missing LUA file. Could you possibly tell me where I am going wrong. Many thanks. John
Arno, found the LUA was already specified in the material editor. Deleted the ref and then export included the LUA along with the mdl file. Added the mdl file to a library and again used SIMDIRECTOR to select the seasonal model and placement on the airport. Exporting the group (of one) from SIMDIRECTOR now successfully creates the bgl and sxml files. Put these in a scenery folder along with a copy of the LUA and fired up P3D. The seasonal tree is positioned correctly BUT NO SEASONAL CHANGE when I change from summer to fall to winter! Where am I going wrong? Is this the correct method or have I to use scripts (not very experienced with scripts!).

The script does not go in the scenery folder, it goes in the scripts folder. In your add-on.xml you can specify where it is.

I forgot about the script already, with visibility conditions in the model you can also do it without a script.
Hi Arno, my dog is threating to bite if we miss another walk! Having no joy here. Trying to use Visibility Conditions in the model. Here is what I am trying to do:
1) Create an HD tree model with visibility conditions
2) Put it in a model library manager
3) Use P3D V5 SIMDIERECTOR to make multiple selections and placements of this object which will seasonally change.
I have no problem with steps 2 & 3. Lost with trying step 1. Here is what I have done so far:
o Imported the 5 seasonal models of the ORBX Chestnut 44M to MCX and exported them as FX MDLs (P3D 4.4 not supported - correct?)
o Imported the SU model and then merged it with the other seasonal versions. Hierachy Editor now shows 5 model parts and material editor shows 5 textures. MCX shows all 5 models superimposed on each other.
UNSURE of next steps.
- Do I go into the material editor and select "seasonal changes" for all five textures?
- When doing this Visibility Conditions window of MCX is blank, also viewing the MODELDEF.XML of MCX shows its not using any of the seasonal part of the modeldef. Unticking "Show only Used" and I then see the complete modeldef file, so MCX is identifying but not using it. Define Seasons of MCX looks ok - I also select "Hard Winter".
- Exporting as FX MDL and then going thru Steps 2 & 3 and I end up with a lovely HD Summer Chestnut - - but for all seasons!
Can you point me int he right direction please? Many thanks.
Hi John,

It's a while ago I implemented the seasonal visiblity condition output, so I had to double check how it works. But this workflow should give you a correctly working MDL file:

  1. In the options make sure that "Use season material script" is set to false, this will force MCX to use visibility conditions instead of scripts.
  2. Load your model that should get the seasonal textures.
  3. Go to the material editor and set the "has seasonal textures" option to true.
  4. If needed, use the season editor to define the start and end days of each season.
  5. Export the model to P3D v4 or P3D v4.4 MDL file (if you use earlier versions that do not support visibility conditions for scenery objects the has seasonal textures option is ignored).
Now you should have a MDL file with the seasons in it. If you load it back into MCX you will see parts with the different textures. And the modeldef.xml editor will show the visibility conditions that have been created.
The dog and I are back from our walk! The MCX MDL file now looks to be good. The Hierarchy Editor shows the 4 model parts each with its correct Visibility Condition from the ModelDef file. The Material Editor show the for corresponding textures - one for each of the models with Has Seasonal Textures set. The Visibility Conditions window shows the correct 0-3 entries from the ModelDef file. The ModeDef editor shows the correct 4 Visibility entries being used.
However, when exported as P3D V4.4 MDL and put thru steps 2 and 3 above - I STILL GET A SUMMER CHESTNUT TREE FOR AL SEASONS!
What I have noticed, when the model is imported back into MCX, in the Material Editor for all 4 textures has the "Has Seasonal Textures" reset to false. Hierarchy Editor, Visibilty Conditions and Modeldef Editor remain as above showing seasons. Don't know if this is relevant.
Beginning to think SIMDIRECTOR maybe the issue here??

That the has seasonal textures option is reset to false on import in MCX is no problem. When you set that option to true again on the next export each of the textures would get their own seasonal textures again. That's not what you want.

Did you make the BGL file that places the object at your airport? If you load that BGL file in the sim the visibility conditions should work.
Hi Arno. I used the following xml to manually place the model into P3D:

<?xml version="1.0" encoding="ISO-8859-1"?>
<FSData version="9.0" xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance' xsi:noNamespaceSchemaLocation="bglcomp.xsd">
<SceneryObject instanceId="{ec14df7a-3d72-4c87-bd55-daa998b6908f}" lat="55 44.4456" lon="-2 22.053" alt="0" pitch="0" bank="0" heading="0" altitudeIsAgl="TRUE" imageComplexity="NORMAL">
<LibraryObject name="{110c03eb-d5e0-4f3a-b2ea-13c1e452b12a}" scale="1.0" />
<ModelData sourceFile="EGGV_Seasonal_CHESTNUT_44M_SU.mdl" />

The first attached jpeg shows:
Tree on left placed with the above xml and copies of the same tree placed on the right with SIMDIRECTOR. As you can see, no seasonality with both methods. So we can rule out SIMDIRECTOR being the issue.
Next thought, I am using ORB TrueEarth GB which has no seasonality, so I changed back to the ORBX Scotland Region and as you can see in the second jpeg, the background ORBX HD Trees have changed to winter season BUT my seasonal chestnut has not!
Could I possibly send you the MCX model output file with the 4 textures for you to inspect??????

Non-Seasonal Trees.jpg

Non-Seasonal Trees2.jpg
It sounds like you do everything right. Sure I can check the files.
Arno, very kind of you. Rar file uploaded (no password)- no rush, have a look at the mdl when you are free.
Many thanks. John


  • EGGV_Trees.rar
    4.9 MB · Views: 105

I don't have P3D v5 installed on my machine, so I tested in v4.4. I placed a single tree at N40 W40 and it works on my machine. The only thing I noticed is that while the sim is paused it won't switch, but as soon as it is unpaused the right texture will show depending on the season. I have attached the file I used to test.


  • tree_test.zip
    1.1 KB · Views: 112
Arno, that's great - at least (with your excellent help!) I am following the correct process. I have just tried the model with P3DV4.4 but get the same results, no seasonal changes.
I THINK this is good news - my model export, BGL files (manual & SIMDIRECTOR) were compiled using the latest V5 SDK MODELDEF, BGLCOMP.EXE.
I will start from scratch again but using the 4.4 SDK in ModCX, Library Mgr and compilations and try first with 4.4 and then with 5.3 to see where the issue is.
The good thing is I now know the ModCX exports are correct so I can now focus on P3D.
Many thanks for your assistance. Will let u know how it goes./ John
If you load my BGL in your sim, does it work then?
Hi Arno - sorry for the delay. We have had a 48 hr internet failure here - traffic accident rearranged BT's switching box , but all fixed now.
Yes , your BGL worked but only if I placed it in the main P3D WORLD folder - in my add-on folder, no switching. Discovered problem was my incorrect folder, lib, model structure. All fixed now and yours and my BLs work great. I have never been so happy to see leaves come off a tree! See pics.


One thing I noticed though - when I export the mdl with only the summer part defined to have Visibilty Condition (false for SP, FA, WI, HW) and then import the mdl again to MCX, all five of these model parts correctly now have Visibility Condition but there are an extra 4 model parts (SP, FA, WI, HW) without visibility condition. The hierarchy editor has to be used to delete these 4 extra model parts, then export and the resultant bgl from the mdl file is perfect.
I don't if this is quirk with MCX or (more likely) there is a setting I have not correctly set. No big deal as it is easily circumvented.
Cannot thank you enough for all your assistance. I am now off to decorate my airport.

If you set the seasonal textures to true on the summer part, while the other seasons are already there, MCX will add the other seasons again. So it is normal that you get the seasons twice then (once with and once without visibility condition).

You should only use the seasonal textures is true when the object only has one variant in it. MCX will add all the other seasons.

But happy to read you got it working.