FS2004-Aircraft brakes not stopping on ground.

I am working on a country airfield where you need to get off the taxi way.
The aircraft brakes work fine on the runway and taxi way but when you get on the surrounding ground they do not stop the aircraft. I know this is possible to have the breaks work on the ground areas, I must have forgotten something.

I have checked the altitudes in AFCD2 and SBuilders FLATTEN poly, they are all the same.
* I have noticed that where I used FSflatten to flatten the area the brakes work on the ground, where I used SBuilders flatten they do not.
Is this an issue with SBuilders flatten? or am I missing another setting in SBuilder?

Thanks, you all have been very helpful.
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I think I made some headway.

1) AFCAD2 layer – set elevation at 942 meters.

2) SBuilder ground VTP2 poly layer points – set elevation points were at 0.

3) SBuilder FLATTEN layer - set elevation at 942 meters.

I tinkered with the VTP2 ground poly and was able to set one of the points to 942 meters.
Saved – and recompiled. Now the aircraft brakes work on the ground.
Is this the solution?

My second question is how to reset all the points elevations in one batch?
Not one at a time, in the “Poly Properties” – “Points” it will not let me reset the elevation.


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Hi Jay:


IIUC, the process you are presently working on is comparable to that addressed in Scott Smart's tutorial:

"Modifying Default Airport Terrain with Sbuilder"


In SB205 - To create a level 'flat' Flatten for terrain surfaces underneath airport BGLComp objects such as RWY / Taxiway / Aprons:

1.) Select the Flatten Polygon so all polygon vertex points are GREEN

2.) Right-click > Properties < "Scenery Builder - Polygon Properties" dialog opens >

> In "Scenery Builder - Polygon Properties" dialog > {General} tab > tick "LWM" > {LWM} tab > tick "Flatten"

3.) In "Scenery Builder - Polygon Properties" dialog > {Points} tab > Set Altitude - All Points Meters (AMSL) > type 942, click [Change] button, [OK]

NOTE: You may- or may not- need to also exclude and replace ...the local default FS9 LWM vector flatten.

(More to come...)


Hope this helps. :)

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Thanks GaryGB, I was able to do this with the LWM Flatten but not with the VTP2 ground poly. It wont let me change elevation (grayed out).
I can change one point at a time though and that seemed to fix the aircraft brake problem.
See attachment.
Sorry, Jay but I was distracted by some inter-current matters as I was editing my post above, and consequently I did not (yet) get to the point where I intended to address the VTP2-specific issue of changing multiple selected vertex points in a polygon all at once. :duck:


IIRC, in SB205 Luis had changed the VTP production methods from legacy SCASM methods used in "pre-SB205" versions of SBuilder to the FS9 SDK VTP2 methods ...to enable production of LWM3 'sloped' flattens, and the work-flow apparently requires a different way of processing Altitude for points:



I will research this further as I attempt to refresh my memory regarding whether there was an easier way to change the Altitude for multiple selected vertex points of VTP2 textured polygons (SB205 'flattens' are non-textured LWM3 polys), and will post here if I can find that info. :coffee:

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Hi Jay:

Before I proceed further researching the option in SBuilder for FS9 version 2.05 (aka "SB205") to change all vertex Altitudes in a single operation for a VTP2 vector textured polygon (aka "ground polygon" for the sake of this discussion), when considering use of such a vector object in conjunction with a:

* LWM3 flatten output by SB205

...versus what IIUC, was a:

* 'Flatten' polygon' output via "FSTFlatten" by Steve Greenwood

...I believe it would first be important to know which method you used in FSTFlatten to create the flattens in your tests above..

In the case where a VTP2 vector textured polygon "ground polygon" is used in conjunction with a 'Flatten' output via "FSTFlatten" by Steve Greenwood, we would need to know which of the (2) methods for producing a flatten ...were used with "FSTFlatten":

* LWM (internally compiled via FSTFlatten; otherwise externally compiled by SDK BGLC... or rhumbaflappy's BGLC_9 ? )


* Area16N (compiled by SCASM)

Thanks in advance for your reply to clarify which work-flow you used for FSTFlatten above. ;)

BTW: In the case where a VTP2 vector textured polygon "ground polygon" is used in conjunction with a separate LWM3 flatten, the VTP2 legacy format vector textured polygon output by SB205 does not require any explicit assigned Altitude in Meters, and is intended to be a terrain mesh-clinging object/

Unlike SBuilderX for FSX / P3D output CVX vector objects , the VTP2 Land / Water mask objects both may use a parameter value of "-9999" to make them follow the local terrain mesh altitudes, if vertex points are created with the correct Geographic coordinate 'winding' direction.

Thus, if one is making a 'sloped' flatten adjacent to flattened and 'level' RWYs and/or Taxiways / Aprons etc., one will be using individual faces in a TIN, which requires careful choice of assigned Altitudes for each individual point as the TIN is constructed with adjoining Edges in its component Faces while adhering to the required range of values allowed to increment- or decrement- the elevation and resulting slope of the adjoining Faces.


SB205 author Luis Sa' explains how to do this in his quoted post linked below:


"Tilted planes

by Luis Sa » Sat Mar 05, 2005 3:05 am


When I finish writing this post, I will upload:


a pre-version of SBuilder 2.05 that uses a new polygon format to support tilted planes. I made routines to convert old projects to version 2.05 but please be careful (now SB writes a backup file just in case). Before Sbuilder 2.05, LINES were sets of XYZ points defined by:

- longitude
- latitude
- width

and POLYS were sets of XY points defined by:

- longitude
- latitude

Now POLYS are sets of XYZ points defined by:

- longitude
- latitude
- altitude

Important Notes:

a) point altitudes in polygons are ignored in all cases except in polygons of type LWM.

b) LWM BGLs are now generated with "Poly3()" style commands. Therefore they will not work anymore in FS2002.

c) when you generate a LWM mask you need to press "Change" in the altitude box in order to set the altitude. "OK" is not sufficient. The idea is to make the working with "altitudes in polygons" very similar to the working with "widths in lines".

Here is a illustrated example to create a tilted plane. You can use this for tilted runways or for LWM rivers that approach the sea (altitude is 0 when the river reaches the sea but not 0 when the river is far from reaching the sea ocean).

In the example I have a polygon with 9 points. I want Point 9 to have an altitude of 20 meters and point 5 to have an altitude of 60 meters. The line that contains points 9 and 5 makes an angle of alpha with the horizontal plane. I want all the remaining points of the polygon to belong to the tilted plane that passes through 9 and 5 and that makes an angle of alpha with the horizontal plane. Here is what I have to do:

I start by drawing a polygon in the normal way (yellow). Then I enter the properties page and define the type of the polygon to be LWM WATER. I enter an altitude of 50 meters which will be applied to all points as soon as I press "Change". I used the value of 50 as it is a value between the extreme values of 20 and 60 that I want to define for the 2 important points - point 9 and point 5!. Then:

I enter the properties of point 9 and I declare its altitude to be 20 meters as in this picture:

And then I do the same for point 5:

I skip the picture where I declare the altitude of Point 5 to be 60 meters and I show the what I get if I reenter the properties of the polygon. I go for the "Points" window which looks very similar to the one you get when you are setting widths in VTP lines. The main difference is that you set altitudes instead of widths:

The window shows the highest and the lowest point which is in accordance to the previous settings. Now if I press "Change" in the Progressive window, points 1 2 3 4 6 7 and 8 will get the altitude that places them in the target tilted plane.

That is all. Do not press "Change" on the left as it would make all points at 40 meters! Just press OK and compile to see the result.

******** Remeshing? will it work? ********

You can set altitudes of individual points and force the mesh to your altitudes. I did not test this and will be glad to hear of any trials.

I also wish to receive feedback on this feature. I plan to use these tilted planes in conjunction with textured polygons to make photo scenery that "brakes" the 4.8 meter barrier.

Regards, Luis"

NOTE: An updated version of that post above is also found in the SB205 Help *.CHM file:

SB205 Menu > Help > {Search} Tab > query string: "VTP"> click [List Topic] button >Select Topic: "LWM Scenery"

AFAIK, the above SB205 method implemented by Luis Sa' was an attempt to simplify some complexity otherwise involved in creation of LWM3 'sloped' polygons using math to compute 'iHeight Fraction' in legacy SDK vector polygon creation methods ...as discussed here:




PS: IIRC, there is a way to set all VTP2 vertex altitudes at once, and I'll need to test a few things before I reply further on that question. :scratchch

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Hi Jay:

I may have found the SB205 GUI "Polygon Mode context only" work-flow for the question in your OP above: :idea:



Polygon Elevations?

"Post by boleyd » 19 Nov 2004 19:49

When importing a large number of water elements from ESRI (MP) all of the elements are set to an elevation zero/nil (sea level). Is there a way to "link" the polygons so that I can set just one to -9999(follow mesh) and have all set that way. I believe that Join requires them to be touching each other."

"Post by Luis Sa » 19 Nov 2004 21:06

Hi Dick,

See my post yesterday. You can now append polygons from a MP file. You will not bother about properties at appending time. They can turn whatever you have set in POLYS.TXT (or through the apending window).

You go to Poly mode. Select All Polys. Press SHIFT (and select one poly with the left mouse - I do not remember if you need this and I do not have Sbuilder at hand!) and right click one poly. The property window comes with the Name box disabled (Grayed). This means that the properties that you are going to set will aplly to all selected polygons.

I must correct one or more things but it is working for me. I even can make an "autocheck" for all selected polygons in one go. One thing that must be corrected is when the property window appears. As "many" polygons are in play, what properties to show? I think that you need to fill all the parameters. If, for example you want to make an overall change of the width of your roads, you need not only to specify the new width (and apply it!) but also the VTP texture and layer number, before pressing the final OK to close the window.

Regards, Luis"


IIUC, the latter post above described what one may do AFTER having 'Appended' a VTP2 polygon from a "Polish MP" vector data file.

However, if I delete a copy of a original VTP 'test' polygon I compiled as a BGL that I had Appended back into the SB205 work-space so that I am basically working ONLY with my original test VTP2 test polygon, the procedure Luis describes ...still works to assign Altitude to all selected vertex points in the polygon at one time. :wizard:

Apparently this functionality in SB205 is 'undocumented' (...to the extent that I have searched thus far).

I will be on the road today, and will have to defer my own additional testing until later this weekend.

I hope that this initial 'lead' might prove helpful for your own testing purposes. :)

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Thank you for your persistence and patience helping me with my questions.
I must apologize though for my awkward way of asking my questions. I think they lead to difficulty for the person trying to help me. I know very little of the nuts and bolts of SBuilder, so it is hard for me to be precise with my questions, sorry.

All the information you have presented here has been extremely helpful with my continued learning. The tutorial on “Airport-background” made me aware of some simple procurers I did not know, very helpful, thanks.

Let me recap where I am at now, now that I have done some trial and error experiments.

1) The aircraft braking seems to be fixed now. When I added the correct elevation to some of the ground poly (VTP2) points, this seems to have corrected the problem. I am building and adding custom ground poly through “Polygon Properties” – “VTP2” – “Named”, I didn’t think to set the elevation because it was grayed out I the “Named” procedure. I did find later that I could go back and assign elevation to its points. This so far seems to have fixed the problem.

2) My side question to “batch” assign to all points is only an easer way if possible, now that I can at least add elevation to individual points.

3) My comment about FSTflatten and SBuilders flatten as a possible key to the problem was unfounded, it only seemed to be a correlation. So this is a mute point. The problem was in the added VTP2 ground poly that I had the elevation at “0”.

*AFCAD2 makes you set the elevation.
*SBuilder’s - Poly – LWM – Flatten, makes you set the elevation.
*But SBuilder does not make it easy to set the elevation with “VTP2” – “Named” poly. So, I thought it was not necessary.

When one is learning this stuff - confusion abounds.

I guess my last question is a clarification that this conclusion is correct?
That not only the elevations of the AFCAD2 and the Flatten are extremely important to be an exact match; but also, if you add a VTP2 ground poly, it needs to be exact? If not problems can occur like aircraft brakes not stopping the aircraft when on a custom ground poly.

Thanks for all your help.

I guess my last question is a clarification that this conclusion is correct?

That not only the elevations of the AFCAD2 and the Flatten are extremely important to be an exact match; but also, if you add a VTP2 ground poly, it needs to be exact? If not problems can occur like aircraft brakes not stopping the aircraft when on a custom ground poly.

Thanks for all your help.
I would say that you are correct on all three of the latter above assertions. :)

At FS airports, for AI / Ground Vehicle Traffic / Approaches / ILS info to all 'work' properly, all these Altitudes must match:

* Airport Background / Boundary polygon

* Airport Reference Point (aka "ARP")

* Flatten (whether LWM3, SCASM, *.ASM ...or CVX vector-based as now used in FSX / Prepar3D)

* RWYs / Taxiways / Taxi-paths / Aprons

* G-Polys (whether LWM3, SCASM, *.ASM ...or MDL-based as now used in Prepar3D with Z-Bias Material Properties).