Road / River redraw - FSX

[pierrot1951]

Hello

After success (difficult, but done!) in changing an airport (place and elevation) to GE place, my new airport is crossed by default river and road...

With SBuilder, it's easy to draw a new river and road, going along the airport.
I compiled with all airport polygons, and new road and river can be seen.

Now, to remove old default road and river, I draw 2 small polygons, with Exclude roads, and Exclude rivers.

It works, but those 2 exclusions extend to a too large area; I read that it was extended to a whole cell? Which size? Now, in this way, I'll have to redraw default roads and rivers for nearly the whole cell!
Is there an other possibility?
If no, I think it would be easier, even if not quite exact, to slightly move the airport, and avoid crossing!

Pierrot - FMEP

 

[Luis_Sá]

Hello,

I will try to explain the concept of bounding boxes which is crucial for exclusions.

For every polygon or line you can imagine a bounding box as the minimal rectangle that totally encompasses that polygon or line. The polygon or line is contained in that box and the box is minimal. If you decrease either the width or the height of the box even by a small quantity, then a part of the polygon or of the line will intersect the box.

Now say that you have polygon A in your default scenery and you want to exclude it. Say that polygon A is of type TA (an airport background, a faltten, a lake, ...). You make a polygon B and give it the type of "exclude polygons of type TA".

The question is: Will this polygon B exclude polygon A? and will it exclude more polygons than polygon A?

In order to know the answser you need to imagine the bounding boxes that contain A and B. If they intersect, then polygon A is indeed excluded. What is causing your problem is, may be, an exclude polygon with a bounding box that is too large.

But take note that there are situations where you can not exclude just one polygon because it is impossible to make a bounding box that just intersects the bounding box of your target polygon.

Regards, Luis

 

[DougMatthews]

Hello,

I will try to explain the concept of bounding boxes which is crucial for exclusions.

For every polygon or line you can imagine a bounding box as the minimal rectangle that totally encompasses that polygon or line. The polygon or line is contained in that box and the box is minimal. If you decrease either the width or the height of the box even by a small quantity, then a part of the polygon or of the line will intersect the box.

Now say that you have polygon A in your default scenery and you want to exclude it. Say that polygon A is of type TA (an airport background, a faltten, a lake, ...). You make a polygon B and give it the type of "exclude polygons of type TA".

The question is: Will this polygon B exclude polygon A? and will it exclude more polygons than polygon A?

In order to know the answser you need to imagine the bounding boxes that contain A and B. If they intersect, then polygon A is indeed excluded. What is causing your problem is, may be, an exclude polygon with a bounding box that is too large.

A minor clarification: while the word intersect is technically accurate, the word overlap might be more clear.

But take note that there are situations where you can not exclude just one polygon because it is impossible to make a bounding box that just intersects the bounding box of your target polygon.

Regards, Luis

Making your exclude extremely small and carefully placing it within the bounding box of the desired target can help. But, yes, there are cases (i.e. a larger water polygon that wraps around a smaller coastal poly the user might desire to exclude) where it is not possible to avoid excluding more than you wish.

A great explanation, Luis!

-Doug

 

[pierrot1951]

Thanks for help!

I didn't take in consideration the concept of box, and I worked in thinking of polygons only.
I'll begin with a very small exclusion, and test result; then increase.

So, it's possible to exclude even a small part of a road of river?

Pierrot - FMEP

 

[DougMatthews]

Thanks for help!

I didn't take in consideration the concept of box, and I worked in thinking of polygons only.
I'll begin with a very small exclusion, and test result; then increase.

So, it's possible to exclude even a small part of a road of river?

Pierrot - FMEP

The most granular you can get is one vector object (in it's entirety).

A couple of other things:

1) the TmfViewer SDK application is a very useful tool for looking at vector (and raster) bgl files. The information from the Identify context option can be very helpful for targeting exclusions.

2) Shp2Vec has a command line option (-ADDTOCELLS) that causes your vector data to be added to the lower priority data from other BGLs. The absence of this option will result in all lower priority vector data of the type(s) you author being excluded from any QMID11 your new data touches.

-Doug

 

[pierrot1951]

Hello

Maybe it will be more explicit with pics:

1/ XSBuilder project

2/ Details of pics from TMF:

North: default FMND airport
A- 1 yellow polygon: (AB) in cvx6137
B- 1 cyan polygon: Exclude_All_Airport_Boundaries

South: new FMND
C- 1 yellow polygon: Airport_Backgrounds_Flatten_MaskMap_ExcludeAutogen
D- 1 inner green polygon: LandClassPoly_Grass_Skirting_2

3/ Details for Road and River
Default road cuts the new airport, and default river cuts in the down-right corner

E- 1 road line (black): new road along the SE corner of airport
F- 1 river line (blue "S" shape): new river

2 new cyan exlude rectangular boxes
G- 1 (left) to exclude old "diagonal" default road of cvx6137
H- 1 (right) to exclude old default river of cvx6137

>>>In XSBuilder
I compile together B-C-D-E-F: file1.bgl
I compile together G-H: file2.bgl

file1 installed in a scenery folder, file2 in an other folder, declared under.
Old airport correctly deleted, new one, new road and river work too, but default road / river exclusions extend to a very larger area (less than QMID11).

Maybe I make a mistake in groups for compiling?
I read your remarks about -addtocells parameter, but I don't know how to rebuild my project so it can to be used with shp2vec.

Thanks for help. Pierrot - FMEP

 

[Luis_Sá]

Hello,

All seems OK to me. Note that both your exclusions G and H could be made much smaller. Your default river bounding box totally contains (so it seems) the bounding box H and your default road totally contains the bounding box G. And they could be located far from the airport if useful (but in the same quad - all they need is to overlapp the bounding boxes of the river and road).

Note that the complete river and road are excluded. That you can not circumvect! The probelm is if you are excluding other rivers and other roads (with the same GUIDS = of the same type) whose bounding boxes overlapp the bounding boxes G and H. If that is the case, try to make G and H smaller and try to locate them in a more "quiet" place.

So, at least, you need to reconstruct the part of river and the part of the road that sit on your particular quad.

SBuilder uses the -ADDTOCELLS, so do not be worried about that.

Regards, Luis

 

[pierrot1951]

Thanks for reply.

Step by step, I think I begin to understand how it works!

1/ Here's the TMF QMID11 for roads + airport area

In aerial view, the 2 legs of road between nodes 1 et 2 are destroyed.

2/ Here's the TMF QMID11 for rivers + airport area

In aerial view, the leg of river between nodes 1 et 2 is destroyed.

That seems absolutely conform with your surrounding box "principle".
So, if I've correctly understood, I can't avoid to redraw that parts, 2 roads between road nodes 1 and 2, river between river nodes 1 and 2?

Now, concerning grouping polys and/or lines to compile:
G and H can be drawn even smaller, just G must be cut by default road vector, and H by default river vector?
BCDEFGH all together?
BCDEF in one, GH in an other?
How to place them?

Thanks for help. Pierrot - FMEP

 

[pierrot1951]

Hello

Exclusion problems for river and roads seem to be solved!
I compiled all polys and lines in same projerct, and it works perfectly.
I easily added some LC polys to figure main cities, and added an important missing road.
Thanks for very nice tool!

A suggestion: would it be possible to select and "copy" a vector object shown in TMF, and paste it in XSB; it would be very easy to apply modifications, just move some points, or change an asphalt road to an other texture. I tried to use a TMF screenshot as background (in SGX), but TMF is only a viewer, and the ratio vert/horiz seems not to be exact, and I couldn't calibrate in SGX.

Pierrot - FMEP