Sorry for not answering earlier.
As you probably know light effects can be defined in the aircraft.cfg file of the airplane in question under the [lights] tag.
The FSX SDK tells us which kind of lights can be defined as shown in the picture below:
This is fine as long as the lights are positioned at static locations relative to the aircraft's body, but what happens if the
airplane has a retractable landing gear and we carefully position the lights where we think there should be?
Well I did this for the sake of the example and added a sixth light (light.5), of the landing kind, to the A321 NEO as follows:
[lights]
light.0=3, -77.90, -0.15, 4.80, fx_navwhih
light.1=2, -77.90, 0.15, 4.80, fx_strobeh
light.2=1, 6.80, 0.00, -5.80, fx_beaconh
light.3=1, 3.83, 0.00, 8.47, fx_beaconh
light.4=4, 47.0, 0.00, 4.1, fx_vclighth
light.5=5, 51.0, 0.00, -8.1, fx_landing
The result, after retracting the nose landing gear, is a hanging light spot beneath the cockpit at a constant distance from the
fuselage flying along with the airplane as long as the landing light switch is on:
In these cases aircraft designers attach these effects to the corresponding moving parts in the model so they move together when
a trigger, such as pressing the G key, initiates an animation such as a landing gear retraction.
So basically we need to tweak the aircraft model in order to fix the problem.
For this purpose I use a freely available tool called ModelConvertX (MCX) which has been around for more than 10 years.
The original intention of the tool was to preserve the work of freeware objects designers, who created plenty of
houses, bridges, trees, cars, airplanes and so forth models for FS9, by converting them to FSX compatible
format so they can be migrated to the, then, new simulator.
MCX allows, among other things, to visualize and change models objects and convert them between formats.
The tool is updated constantly. These days the author is working mostly on FSX to MSFS 2020/2024 conversions.
MCX can be found here:
https://www.scenerydesign.org/modelconverterx/The next picture is what we see after opening the aircraft model in MCX with the landing gear opened
Take a look a the blue,red and green lines around the gear strout, they can be better visualized if the model is
rendered as a wire frame:
The small red squares represent the position of the effect relative to the aircaft's body parts in 3D space.
Each such red square is the center of a kind of orthogonal 3D space coordinate system represented by the
red, blue and green lines.
The angular disposition of this coordinate system represents the rotation of the effect relative to the longitudinal,
lateral and vertical coordinates of the airplane itself.
The direction in which the 'light' particles of the light effect are emitted goes along the green axis and if we imagine an arrow,
then the red square is its head and the end of the green axis its tail.
If we follow the green line I marked in the picture above as the landing light effect, we can see it meets the ground very
close to the front landing gear wheels. This is why the landing light illuminates just a small triangle on the ground.
Don't ask me how I figured out which one of those many red dots on the front landing gear strout is the landing light effect, I leave
this to you as an exercise should you decide to play around with MCX.
So from this point on it is just a tedious trial and error process composed of little adjustements to the landing effect's position
and angle of incidence and testing the result in the sim until we are satisfied with the results.
This is what I ended up after several iterations
In the same fashion I adjusted the extra landing lights at each side of the airplane located at the wing's root.
These lights are also attached to retracting lamps.
The combined effect of all landing light sources can be seen in the 'After' picture of my previous post.
I'll release the revised PW and CFM models shortly.
Well, I believe I've answered your question
Cheers
