RC-SIM

Hans Wonner has created a workshop in which he explains, how you can modify the weather and the daytime in the 3D-sceneries of AFPD.

OK, let’s start with our “Weather God” seminar.

If you open the .geo file of the scenery you will find the following line, just below the start-position:

//               height  tiling ca      cb filename
CLOUDS 155       6       0.45  0.9 texture/cloud.tmt

This is our “Weather cockpit”

In the sceneries “eggeland” and “mountlake” this part is missing. Therefore there are no clouds in this sceneries. If you like to have clouds you can copy these lines and insert them into the .geo files (below the “Cube” line).

The first number “height” (155)
gives us the altitude of the clouds in meters. If you decrease the number from 155 to 55 the cloud level will be 100 meters lower. You must save the file first, otherwise you will not see any change (also backup your .geo file at first).


The second parameter is  “tiling” (6)

//              height  tiling   ca     cb filename
CLOUDS 155       6       0.45  0.9 texture/cloud.tmt

This number controls how often the same cloud texture will be replicated from one end of the sky to the other. With numbers around 5 this iteration does not catch the eye. With numbers above 10 it comes more and more obvious.
If you set the number to “0” you will get a diffuse cloud ceiling  without structure.


The third parameter is “ca” (0.45)

//              height  tiling   ca     cb filename
CLOUDS 155       6       0.45  0.9 texture/cloud.tmt

This value controls the  contrast of the clouds. With low values the cloud mist is very fine or not visible. The sky then looks less cloudy.
The higher the value the higher the contrast. The mist becomes more and more a thick cloud.
But because the cloud texture is quite rough there will appear more and more “saw-teeth”.


The last parameter is “cb” (0.9)

//              height  tiling   ca     cb filename
CLOUDS 155       6       0.45  0.9 texture/cloud.tmt


This value controls the contingent of clouds on the sky (inversely proportional).
The smaller the value, the higher the contingent of clouds.
Very small values (below 0.2) might look a little strange.



This is not the End, we also have the “Fog-function”.

This function extents the possibilities significantly (soft-focus, etc.) But you can also colour the fog.

Therefore we open the main folder of  Aerofly. In the sub-folder “Config” open the file “main”. At the bottom end of the file we find:

gl_fog 0
fog_density 0.00092
fog_color 0.60000 0.60000 0.60000


If you lower all three values of “fog_color” in the same way ( e.g. all to 0.30000), the fog will become darker and more grey (don’t forget to save!).

If you set the three numbers to 0.0000 you will get black fog that can be used for nice thunderstorms or evening moods.

This works fine because in the graphics menu the density can be adjusted in very small steps and also can be switched off or on with one click.

Now we will colour our fog.

Again, “config > main” and then look for the “fog” lines.

gl_fog 1
fog_density 0.00113
fog_color 0.60000 0.60000 0.60000

If the three numbers have the same value the fog willl be white (if 1), grey (below 1) or black (if 0). The three numbers are like the three sliders for the smoke in the graphics menu.

The first number controls the red contingent
The second number the green
and the third number the blue.

For a sunset we need a lot of red, a little green and no blue:

fog_color 0.50000 0.10000 0.00000


For a yellowish sunset we take the same amount of red and green. This gives us a yellow with a little orange touch.

fog_color 0.60000 0.60000 0.00000


For a „real“ sunset we must set the sun to a lower position and modify the sun- and ambient-light.
Let’s go to the next block of our “cockpit”, the “light-block” of the .geo file:

LIGHT_POSITION 0 0.20 -0.40 1.00 0
LIGHT_AMBIENT 0 0.70 0.70 0.70
LIGHT_DIFFUSE 0 1.00 1.00 1.00
LIGHT_SPECULAR 0 1.00 1.00 1.00

Now we modify the direction and height of the “Sunbeams”.

Therefore we need the line LIGHT-POSITION.

The first number does not have any meaning, it’s the same for the last one.
The three numbers in between are  setting from where the sun will send her beams.

The first number shifts the sun in north-south direction.
The second shifts it West (Plus) or East (Minus).
The third one modifies the height.

The values of the numbers don’t matter, the important thing is the proportion between them.

0.51.20.7 gives the same result as 1.02.41.4

A compass card is helpful for orientation. Place an aircraft in the direction where you like to have the sun. Now estimate the proportion of the orientation.

To adapt the sun exactly to the shadows of a panorama I normally take my “night-airship” from the AFP download. and mirror it.
Then I fly around near the position where the sun should be and analyze the reflections on the airship. If you fly in front of the “sun” and you don’t have any reflections on the airship, the direction and the height of the sunbeams are correct.
This needs a little practice, but after a while it works fine.

The solution in this case is: Set the sun to south-east in 45 degrees height:
LIGHT_POSITION 0 -1.0 -1.0 1.00 0


Now we come to the second line of the „light block“:

LIGHT_AMBIENT

With this value we control the strength and colour of the GENERAL AMBIENT LIGHT of the scenery.
The first zero doesn’t matter, but the 3 following numbers:

LIGHT_POSITION 0 0.20 -0.40 1.00 0
LIGHT_AMBIENT 0 0.70 0.70 0.70
LIGHT_DIFFUSE 0 1.00 1.00 1.00
LIGHT_SPECULAR 0 1.00 1.00 1.00

What we see here is a white midday light like in all IPACS sceneries.
The red contingent (1. number) is the same than the green (2. number) and the blue (3. number), always 0.70. This altogether gives us a white light, like with a closed cloud cover. But if a blue sky appears, the blue contingent of the ambient light increases significantly and also the green grass reflects the light. In that cases I always set the colour contingents in a graduated manner:

LIGHT_AMBIENT 0 0.5 0.55 0.6

Because midday is over, the ambient light has decreased in general, like shown in the example above.

Strength and colour of the sunbeams is another topic and will be explained next time.

The next to last line is LIGHT_DIFFUSE:

LIGHT_POSITION 0 0.20 -0.40 1.00 0
LIGHT_AMBIENT 0 0.70 0.70 0.70
LIGHT_DIFFUSE 0 1.00 1.00 1.00
LIGHT_SPECULAR 0 1.00 1.00 1.00


Unlike to its name, it is not responsible for diffuse or scattered light (that’s what LIGHT_AMBIENT is for), but for the aligned sunbeams. Their source we have set already with the first line.

The 3 numbers are again red-, green- and blue-contingent of the sunlight.

For morning sun decrease blue 20% and green 10% compared to red. This results in a yellowish light.

LIGHT_DIFFUSE 0 1.00 0.900 0.800


For the evening light we have to graduate even more and decrease the green contingent a little more to get a more reddish light.

LIGHT_DIFFUSE 0 1.00 0.65 0.500


If you prefer a loud evening sun you can double the values:

LIGHT_DIFFUSE 0 2.00 1.30 1.00


OK, that have been the most important “levers” of the weather machine.

The last line:
LIGHT_SPECULAR 0 1.00 1.00 1.00
has not too much effect and can be left untouched.

Most of the explained can also be done in Easyfly, but the “cockpit” has a different composition there.

Thank you for your attention

Hans