Rotate with Wind - can't make it work


I have been trying this for a couple of hours and it doesn't work for me.

I am back to FS9 to make sure.

I make a simple object, with gmax, a box. I export it and generate an mdl.

Then I tweak it with MDL Tweaker latest version, and add the condition "Rotate with wind".

Then I save the mdl, which is saved with the name xxxxx_tweaked.mdl.

I, then, place it in two places somewhere in FS9, using Ob Placer, the objects side by side to make sure the two are visible at the same time, oriented to 000 degrees.

Then I change the wind to a number of directions, but the things do not move at all, are always turned North, the way I placed them.

It it more complicated than this?


Hi Fern,

Can you try a hand edit of the ASM file ? The code below is how I did mine... I highlighted the line in RED...

Here is the one I used - I forget where I got the line - maybe Arno posted it for me... It wasn't too long ago...

; This file was automatically generated from E:\My Desktop\MSFS Scenery\Model Work\WindTee\WindTee.X
; using the MakeMDL tool.  Do not edit by hand, re-run the
; tool instead.
; generated on 02/23/13 23:05:04
; BGL model for E:\My Desktop\MSFS Scenery\Model Work\WindTee\WindTee.X
; $Header:$
; Final Status:   48 polys
; Alpha Status:   0 polys
; Light Status:   0 polys
; Library Status: 0 polys
; Start Time: 02/23/13 23:05:04
; Stop Time : 02/23/13 23:05:04
; Modeling units = 1.0000
; Radius = 5.9635
; Radius in meters = 5.9635
; Radius in modeling units = 6
WindTee_top label BGLCODE
texture_riff_start_WindTee	label	word
    db  'T','E','X','T'   
    dd  texture_riff_end_WindTee - $ - 4  
    TEXTURE_DEF TEXTURE_BUILDING    , <255,255,255,255>, 2.416854, "YELLOWWOOD.BMP"	; 0
texture_riff_end_WindTee label word       

material_riff_start_WindTee	label	word
    db  'M','A','T','E'   
    dd  material_riff_end_WindTee - $ - 4  
    MATERIAL_DEF 1.000000,1.000000,1.000000,1.000000,  0.392157,0.392157,0.392157,  0.000000,0.000000,0.000000,  0.000000,0.000000,0.000000,  0.000000 ; 0
material_riff_end_WindTee label word       

vertex_riff_start_WindTee	label	word
    db  'V','E','R','T'   
    dd  vertex_riff_end_WindTee - $ - 4  
    VERTEX_DEF    -5.396000,    2.540000,    0.076000,  
vertex_riff_end_WindTee label word       

bgl_riff_start_WindTee	label	BGLCODE
    db	'B','G','L',' '
    dd	bgl_riff_end_WindTee - $ - 4
LOD_0_WindTee	label	BGLCODE

; NonAlpha
WindTee_NonAlpha label BGLCODE
[COLOR="Red"][B]   POINT_VICALL WindTee_Main_1, 0, 0, 0, 0, 0, 0, 0, 0, global_winds_surface_direction    ; Node 1 - Main[/B][/COLOR]

WindTee_Main_1 label BGLCODE
    MATERIAL 0,0 ; <255,255,255,255> YELLOWWOOD.BMP;;;
    DRAW_TRI_BEGIN 0, 92
    DRAW_TRI   80,  20,  15 ; poly=1 part=1
    DRAW_TRI   72,  80,  15 ; poly=2 part=1
    DRAW_TRI   17,  77,  69 ; poly=3 part=1
    DRAW_TRI   12,  17,  69 ; poly=4 part=1
    DRAW_TRI   79,  82,  73 ; poly=5 part=1
    DRAW_TRI   70,  79,  73 ; poly=6 part=1
    DRAW_TRI   19,  16,  10 ; poly=7 part=1
    DRAW_TRI   13,  19,  10 ; poly=8 part=1
    DRAW_TRI   78,  18,  21 ; poly=9 part=1
    DRAW_TRI   81,  78,  21 ; poly=10 part=1
    DRAW_TRI   11,  68,  71 ; poly=11 part=1
    DRAW_TRI   14,  11,  71 ; poly=12 part=1
    DRAW_TRI   89,  66,  61 ; poly=13 part=1
    DRAW_TRI   84,  89,  61 ; poly=14 part=1
    DRAW_TRI   63,  86,  75 ; poly=15 part=1
    DRAW_TRI   58,  63,  75 ; poly=16 part=1
    DRAW_TRI   88,  91,  85 ; poly=17 part=1
    DRAW_TRI   76,  88,  85 ; poly=18 part=1
    DRAW_TRI   65,  62,  56 ; poly=19 part=1
    DRAW_TRI   59,  65,  56 ; poly=20 part=1
    DRAW_TRI   87,  64,  67 ; poly=21 part=1
    DRAW_TRI   90,  87,  67 ; poly=22 part=1
    DRAW_TRI   57,  74,  83 ; poly=23 part=1
    DRAW_TRI   60,  57,  83 ; poly=24 part=1
    DRAW_TRI    8,   4,  25 ; poly=25 part=1
    DRAW_TRI   30,   8,  25 ; poly=26 part=1
    DRAW_TRI    1,   6,  27 ; poly=27 part=1
    DRAW_TRI   23,   1,  27 ; poly=28 part=1
    DRAW_TRI    7,   9,  31 ; poly=29 part=1
    DRAW_TRI   28,   7,  31 ; poly=30 part=1
    DRAW_TRI    3,   0,  22 ; poly=31 part=1
    DRAW_TRI   24,   3,  22 ; poly=32 part=1
    DRAW_TRI    7,   2,   5 ; poly=33 part=1
    DRAW_TRI    9,   7,   5 ; poly=34 part=1
    DRAW_TRI   22,  26,  29 ; poly=35 part=1
    DRAW_TRI   24,  22,  29 ; poly=36 part=1
    DRAW_TRI   53,  42,  37 ; poly=37 part=1
    DRAW_TRI   48,  53,  37 ; poly=38 part=1
    DRAW_TRI   39,  50,  45 ; poly=39 part=1
    DRAW_TRI   34,  39,  45 ; poly=40 part=1
    DRAW_TRI   52,  55,  49 ; poly=41 part=1
    DRAW_TRI   46,  52,  49 ; poly=42 part=1
    DRAW_TRI   41,  38,  32 ; poly=43 part=1
    DRAW_TRI   35,  41,  32 ; poly=44 part=1
    DRAW_TRI   51,  40,  43 ; poly=45 part=1
    DRAW_TRI   54,  51,  43 ; poly=46 part=1
    DRAW_TRI   33,  44,  47 ; poly=47 part=1
    DRAW_TRI   36,  33,  47 ; poly=48 part=1

bgl_riff_end_WindTee	label	BGLCODE

; This file was automatically generated from E:\My Desktop\MSFS Scenery\Model Work\WindTee\WindTee.X
; using the MakeMDL tool.  Do not edit by hand, re-run the
; tool instead.
; generated on 02/23/13 23:05:04
Hi Fern,

Oh - one other thought - did you exit MSFS after you placed the objects - - - then restart MSFS before trying to see if the animation worked ??? The animations don't kick in until a restart...

Re-starting and editing asm

Hi, Scott

Yes in both cases: I can edit the asm, and I have re-started FS several times, still no go.

I was hoping that MDL Tweaker would do it for me, but I am prepared to edit the asm file.

Gosh, this is tiring sometimes :D

Thanks. If you can think of why the xxxxx_tweaked.mdl isn't rotating (just a simple box), let me know.



Resource contributor
I used MDLTweaker and it works for me, so I know it does indeed create an object that will rotate into the wind.

The only difference for me was I placed the object into a library BGL and used Instant Scenery to place the object twice.
xxxxx_0.asm edit didn't work

Hi, Scott

Well, editingn the xxxxx_0.asm file didn't work, because bglc didn't like it. I can't compile it. It gives me an error

BGLC_9.exe gets excited with "POINT_VICALL".

I copied from your file and pasted in mine, changing the name of your object to mine, of course.

Hmmm... Glad if you have more ideas. I really wished MDL Tweaker did the trick...


Here are my files

OK, fellows, if you can, have a look at my files:

1. The object, gmax file.

2. The mdl file after exporting from gmax.

3. The tweaked mdl

(Note: I tried tweaking with all my MDL Tweaker versions...)

4. The bgl file that locates the object in the Kamarang airport SYKM.

What I did for testing is to go into Weather, customize it, give it some wind and change the direction.

If you have the time...





Resource contributor
Not sure about FS9, but in FSX with these objects you must place 2 instances or they will not rotate with the wind.
Hi Fern,

Sorry - I don't know what to tell you - attached is my source file (X) for my wind tee and my hand tweaked (ASM) code that produces a working wind tee - maybe you can reverse engineer it ??? FS9 requires two objects as well...



Last edited:


Resource contributor
OK, here are my results. They are totally weird, and I don't know what to make of them.

1. Added your tweaked MDL file to a library BGL and placed two of them at SYKM with Instant Scenery. No turning with wind direction.

2. Added my own wind vane MDL file to the library BGL and also placed two of those at SYKM. No turning.

3. Placed two of my own wind vanes at KOAK, into the same placement BGL file. They respond fine.

4. Placed two of YOUR wind vanes at KOAK. They respond fine. CONCLUSION: your tweaked MDL file is fine.

5. Went to SYKM and looked at the existing 4 objects. Now they turn just fine with the wind.

6. Removed the 4 wind vanes at KOAK. The vanes at SYKM still turn fine.

7. Removed MY 2 wind vanes at SYKM. Your two vanes still turn fine.

8. Removed my MDL file from the Library BGL file. Your two vanes still turn fine.

So I ended up with the correct situation (two of your vanes at SYKM turn fine with the wind), but I had to go through a tortuous path to get there! I have no idea why this should be happening.

Hope this helps (but I'm not sure how),


Resource contributor
I have also done one more thing

I've now removed the placement BGL file and created a new one just with two of your objects at SYKM using the working library BGL file , and they rotate fine right from the start.

Then I deleted my library BGL file, and re-created it. I then placed two of them at SYKM using a brand new placement BGL. They rotate just fine. Very odd.
One step closer

Hi, Scott

OK, I got your three files:


Also found the editing, which you had shown before.

Question 1:
Did you use gmax with gamepack for FS2002 to create these files?

Question 2:
Did you export it as a bgl?

Question 3:
Once you edit it, how to you complile the new bgl if the three files do not contain lat / lon?

Thanks, Scott

Last edited:
Hi Fern,

I don't use GMax - I use another modeling software package called 3D Canvas - it's big over on the MSTS side of the house... It exports to the "Direct X" file format (or just about any other format I can think of) which MakeMDL will accept as input... You can run the X files I sent through MakeMDL - select "keep files" and it will generate unaltered (no rotate with wind) ASM code that you can compare to my modded ones... If you want to compile the altered ASM files - you'll need that BGL9C compiler... I never position the models up front - well except for ground polys - I use Arno's Library Maker to make a library BGL for Instant Scenery and position the models that way...

Hope it helps...

Last edited:
Not this time

Hi, Scott

This time it didn't help much, but I thank you.

This is far more capricious than I though. I was expecting "tweak it with MDL Tweaker, add "rotate with wind, and that will be it". No such luck. That condition doesn't seem to work much.

However, I am testing another way of doing it, which is to condition several objects (10, in my case), each to appear only under wind speed and wind direction designated to it. So, it it is windy, the calm-wind one disapperars, and one of the other 9 appears, depending on which direction the wind is coming.

Yes, very complicated to control something that is hardly visible. My object is just an arrow less than a metre long, black, on top of a 4-metre pole.

This is further complicated by the fact that, according to the numbers in Arno's MDL Tweaker, the 0-to-360 degrees of wind direction are entered in a scale of 0 to 65535, not 0 to 360. This means that 40 degrees would be around 7463 but that number turns out to be 48 degrees. And so on.

Another complication is de necessity to have at least another wind-conditioned tweaked object in the scene at the same time and, as I found out,it works better with TWO extra objects.

Anyway, I continue to try. FS is very different from Train Simulator, I think.

If anyone else has other ideas, please let me know.