FSX Slime lights (formation lights) in FSX and P3D.

I would think this has come up before but I couldn’t find a reference to it, so apologies if I’ve missed it.

What I‘m interested in is making slime lights (green formation strip lights) in Gmax for FSX and P3D military AI aircraft. I would imagine that they would work in the same way as logo lights and cabin lights.

In FS9 it’s easy – a light map (.L) is assigned as a texture and hey presto, the lights come on as the aircraft leaves the runway hold to line up for take-off. It partially works in FSX too but the lights remain on the whole duration of dusk, night and dawn which is unrealistic.

I’ve managed to do it by placing narrow planes with the slime light texture on it (day and night) in position over the fuselage and fin polygons. Leaving a small gap and turning off shadows in the material settings to avoid co-planar flickering. The planes are linked to a tiny hidden polygon that has some visibility xml code assigned to it so the night texture only appears when the Nav light is on. It works very well but it’s very fiddly and time consuming to do.

I just wanted to check whether there is in fact a way of making the lights work with FSX material settings, firstly by allocating a texture in one of the slots (which slot?) and then setting the emission properties. I tried Multiply Blend and user Multiply Blend with the night texture in the self illumination slot but that didn’t work.

Is there a way of doing it please with materials instead of polygons?

John
 

n4gix

Resource contributor
I make my slime lights using two polygons with <slime_off> and <slime_on> visibility tags. I can then control on/off via a switch, or any other logic as I desire. Since your use case is for AI, just set your visibility conditions for not-daytime. This way they will only show dawn/dusk/night. You could also add a condition for off-ground for even more restrictive control.

The "off" polys have the unlighted material applied.
The "on" polys have the lighted material applied. The lighted material uses a 'lighted' version of the off bitmap in the diffuse and self-illumination slots, and using the Additive Mode. Note also that I use SrcAlpha as origin, and InvSrcAlpha as the destination blend. This simply allows me to control the transparency via the Alpha channel for unused areas of the texture, such as placing a round light on a square polygon if needed:


 
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Thanks Bill. I used a similar polygon method and it does work well. It's quite fiddly though to get the polygons as close as possible to the underlying airframe polygons without causing flickering so it's not quite as precise or as quick as using a lightmap in FS9. I'm quite happy to stick with the polygon method but I'm just curious as to why a lightmap won't work in FSX and P3Dv4. The default B737 aircraft in FSX has a night texture (._LM) for cabin lights. Does that work in the same way as an FS9 ( ._L) lightmap because it's controlled from a panel switch but doesn't in an AI aircraft because there is no human control?

John
 

n4gix

Resource contributor
AI don't have switches of course, so you have to resort to embedding some logic into the <Visibility> script to turn slimes on/off based on several conditions. Here are scripts I use to control a Decision Height light using multiple conditions for the on/off state:
Code:
  <PartInfo>
    <Name>B350i_DH_Lighted</Name>
    <Visibility>
      <Parameter>
        <Code>
          (A:RADIO HEIGHT,Feet) (A:DECISION HEIGHT,Feet) &lt;
          (A:SIM ON GROUND,bool) ! and
          (L:ANNUN_TEST,bool) or
          (A:ELECTRICAL MASTER BATTERY,bool) and
        </Code>
      </Parameter>
    </Visibility>
  </PartInfo>

  <PartInfo>
    <Name>B350i_DH_Unlighted</Name>
    <Visibility>
      <Parameter>
        <Code>
          (A:RADIO HEIGHT,Feet) (A:DECISION HEIGHT,Feet) &gt;
          (A:SIM ON GROUND,bool) or
          (L:ANNUN_TEST,bool) ! or
        </Code>
      </Parameter>
    </Visibility>
  </PartInfo>
To eliminate flickering, I cut out the fuselage mesh where the light polys are placed.
 
I'm probably keeping it a bit more simple than that Bill by just using a Nav light condition in the <code> block. When the Nav lights are on, the slimes are on too from about 15 minutes before AI departure to shutdown at destination. Alternatively a strobe condition will switch on the slimes at the runway hold and switch them off again as the AI leaves the runway at the destination..

That's a good tip about cutting out the slime polygons. I'll do that next time.

Thanks for your help as always.

John
 
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