It seems that with the nav lights it is one step forward and two steps back!
To recap, FSX in DX10 mode does not show nav lights. What it does show is an effect of the (missing) nav light shining on the plane. As an oddity it does briefly show the nav lights during the engine start sequence.
The way that nav lights are implemented in FSX (DX9 or DX10) is that there is an effect which lights the plane and a separate drawcall that uses a light corona texture. It is the latter which makes the light visible from outside the plane and what is missing in DX10. This is seen clearly with the invisible beacon which lights the tail.
In DX10 all we see is the green glow on the wing
The effects are defined in the aircraft.cfg – here for example is the Mooney Bravo
//Types: 1=beacon, 2=strobe, 3=navigation, 4=cockpit, 5=landing
light.0 = 3, -2.65, -18.25, -0.18, fx_navred ,
light.1 = 3, -2.65, 18.25, -0.18, fx_navgre ,
light.2 = 7, -2.75, -18.25, -0.18, fx_recog ,
light.3 = 7, -2.75, 18.25, -0.18, fx_recog ,
light.4 = 1, -17.30, 0.00, -1.25, fx_beacon ,
light.5 = 4, -2.90, 0.00, -0.25, fx_vclight,
light.6 = 2, -5.40, -18.35, -0.13, fx_strobe ,
light.7 = 2, -5.40, 18.35, -0.13, fx_strobe ,
fx_navgre is the green glow and can be found in the effects directory.
What I found was that the behaviour of an effect used in plane lights depends on whether the Light=1 option is set inside the effect, and the location of the light in relationship to the centre of the plane.
A light illuminates the plane but is not visible as a light source – hence with DX10 all we see is the green glow. If I change the effect not to be a light effect it becomes visible but no longer illuminates the plane. Moreover FSX also imposes some constraint that the effects associated with nav lights cannot be seen from a viewing point outboard of the light itself. This can be seen by using the spotter plane view and moving around the place in DX10 looking at the strobes.
Here I have raised the red light by 1 foot – this from inboard – you can I hope see the red light above the wing.
This from outboard – no light!
Hence my faintly ridiculous approach of creating Nav light effects that have large offsets and are placed on the wrong side of the plane. A secondary problem is that effect that aren’t defined as lights (in the internal illuminating of the plane sense) are only displayed when the landing lights are on
The good news is that I am making progress! I have added vertical offsets to all the light components to make testing easier.
The best I have managed so far is the red,green nav lights, orange beacon and one strobe working. Adding the second strobe stops the beacon illuminating the tailplane!!