Controlling a simple light visibility distance? I can't

I am puzzled by the way(s) to control the visibility range of a light source.

Taking the example of the simple fx_chanlbuoygre : let's say this effect is a bit over done, as the green light is visible from more than 7 km away which is not realistic. In harbours in real life, these lights are rather faint and visible from, say, 1000 m (always for the sake of demonstration).

Whatever the value I set to Radius, the buoy remains visible from these 7 km.

OK so let's try adding a LOD=1 parameter, hoping to see this buoy turned off when afar: no joy, this turns it off completely!

Well let's try something else, setting a lower particle color intensity (from 255 to 128 for example): no result, the light may look a bit smaller/darker but it remains visible from 7 km away.

Same thing when setting a smaller diameter (Scale parameter): visibility range stays the same.

Worse enough: some light effects have a particle type=19 instead of 25, and nevertheless behave like luminous souces!?

And what il the Light=0/1 made for since I can't see no difference?

So, will I have to use a controller to lower this distance? I can't believe all these parameters are useless!

I've read the SDK documentation over and over again, without success.

I must miss something, but what???


Just to say I came to the same conclusión, trying to make an effect, nothing fancy, just to make the light be turned off in a more extended time. just that. and give up. just had succes retarding the emitting light. in three seconds. with "delay" parameters, but nothing more. I know that scaling the light work too, it's all what i got after an entirely half day.really frustrating the effects subject. and we have just what the SDK say, no tutorials not even a trick.
You could try scaling the light but don't know if it affect the visibility, as all just conjectures.
According to what I have read in the time, you could focus on the "controllers" subject when working on effect, seen people use this much, though as usually very few information about this, some lose thread here and there.
Yes of course one can use a type 3 controller and add a distance value, it works. But it adds an effect to control another effect, so makes 2 effects running.
I wouild have preferred to keep just one. ;)

Effects are weird, and as you say: we just have this very summary SDK document written by a geek years ago with apparently not the smallest concern for noobs like me who'll try to understand something from what he wrote.
For sure everything was clear in his mind since he surely developed the code, but for us...

I wonder if someone EVER developed his own original effect since the launch of FS, or if all developers just simply try to tweak MS originals and basta!
I know people créate his own texures but no more . Yes that is my impression, Fsx people made things for his own, not for newby that had the weird idea of developing for the simulator sceneries. sometimes I don't understand very well all this. something important as is to deal with those effects, I would invest great part of my time but I can't even, no knowing the starting point. well at least we can tell off our frustration.
FWIW, I use effect controllers a lot. I created a FLAK package for use by the online group I fly with, flying the WWII missions of the 91st Bombardment Group. I created FLAK 'sites' that consist of 64 controllers, stacked in elevation and activated by proximity. I placed these 'sites' around targets throughout 'occupied Europe' with each site 'covering a 2 km area. I heavily defended areas there may be 8, 10, 12 or more 'sites', each with 64 controllers. Each controller activates 2, 3 or 4 effects...the FLAK explosions that occur at randomized distances and directions from the controller.

The point is, having 2 effects running has NO measurable impact on the FSX enviroment. The total number of controllers in my FLAK package is something in excess of 10,000.

As to the distance that a light is visible an elusive feature. I have placed lights on static ships along airway routes to be used in conjunction with a weathership gauge. In that application I wanted a maximum range but it seems that about 7 to 12 statute miles was the limit and I'm not really certain how I achieved that range.

The MS SDK's, as well as most other MSFS documentation is poorly written and terribly lacking in useful content. In most cases, all the documentation does is 'state the obvious' and not providing useful examples or insight into the subject at hand. Most of what I have learned in dealing with various aspects of FSX has been learned empirically or from reading the discoveries of others in forums such as this. My most recent 'exploration' of an MSFS utility is with the FS9 Weather SDK and the WMaker.exe program. The documentation for that program is probably the worst I have ever seen with respect to the interaction of elements such as cloud or wind layers and the extent that parameters in those layers are limited before they cause unexpected results due to interfering with another layer.

So, we are pretty much left to our own devices to explore and learn the ins and outs of the MSFS world.

Thanks for answering Paul.
I came to the same conclusions.

If we use a type 25 (light emitting effect) the visibility is out of proportions with the actual size of the source. Say a "small lamp" for a tiny harbour lighthouse only 8" in diameter will be visible miles away but when you fly by becomes nearly invisible due to its size. A work around is then to use lower RGB values, say 64,64,64 for a low glow white instead of 255,255,255. But the result is not perfect (far of).

If we use a type 19 (normal refelctive effect) then we have a better control, but the consequence is a much shorter visibility range. The workaround would then be to use a "huge map" for the light source in order to exetnd the distance. But the trouble then comes from close when this map is seen really huge compared to its environment. Thus the necessity to create a series of lights based on LODs, the closer ones having a relatively smaller map, the farther ones bigger maps.

It's getting a bit too complicated to remain fun to do! ;)
Hi folks,

I've been struggling with the visibility range of for some time too. I much appreciate the comments above, especially regarding type 19 vs 25 effects. I played with this parameter some time ago, but I should try again. I'm mostly working with P3D now, and so far all the light effects I've made, even huge test ones, turn off at a quite consistent distance, ~5800 meters. So until I find a work around for that, I'm stuck trying to get reasonable visibility ranges for marine lights. For what it's worth, I've been gradually annotating the ESP effects SDK; it's linked on my blog (linked in the sig line). Most of the annotations have to do with wake or smoke effects, but there might be something useful there. Maybe I can add the consensus view of what the effect type actually does. The cryptic notes in the SDK don't help that much. As to making effects from scratch, yes, people do it. It's sort'a fun once you know what the various parameters actually do in a quantitative sense.:)



Resource contributor
Hi Larry et al. I am curious about the visibility range you are able to achieve with your effects. I'm back working on a version of AFLT (Airfield Lights Toolbox) for P3D. I've managed to emulate every normal type of airfield light (omni, obstruction, split, VASI/PAPI, wigwag and strobe) using effects attached to simobjects - controlled with Simconnect. Unfortunately, I'm getting only about 1km of visibility. I'm using type 19 effects since Type 25 in P3Dv2 won't display against many backgrounds - including runways and taxiways - not helpful for airfield lights. Size of the effect doesn't seem to matter. The BBOX dimensions are 200 m/per side and RADI = 1000m - to ensure the model itself won't turn off prematurely.

Thoughts, anyone?

I have been working on other aspects of the FSX SDK for so long that I would have to allocate more time to refreshing my memory on FX coding.

But I have recently been intrigued about possible ways that LODs may play a role in attached Effect visibility distance, and whether there may be some correlation between the Fx numeric Type, display distance, and one's FS flight start location.

Although we are obviously herein discussing Fx and not terrain mesh, I am compelled to still be curious as to what extent this FX run time rendering engine display distance behavior may be 'comparable' to how the FS rendering engine "refuses" to display small, higher LOD resolution terrain mesh tiles (with smaller Geographic 'trigger areas" in their BGL file headers) when a flight is started outside the small higher LOD resolution terrain mesh tile located over a lower LOD mesh BGL covering a larger expanse of ground (outside the area of that higher LOD mesh BGL).

If, however, a flight is started inside the local small higher LOD resolution terrain mesh tile inset within- and above- a lower LOD mesh BGL, the FS rendering engine "allows" display of that small higher LOD resolution terrain mesh tile.

To "allow" display of that smaller, 'higher' LOD resolution terrain mesh tile, one must make its Geographic "trigger area" in the BGL file header ...larger, by expanding the range of LODs within its BGL output by FS SDK Resample to include lower LODs that cover a greater expanse on the ground. This effectively allows that BGL to achieve a greater display priority over the underlying BGL containing only the 'lower' LODs at run time via the FS rendering engine ...regardless of one's start location for a flight.

Because this behavior is somewhat comparable to reported display quirks of the Fx numeric "types", I'm curious as to whether there might be any functional commonalities affecting the FS rendering engine.

One might wonder whether there may be more that can be implemented in the way of "trigger" Radii, LODs and MIPMAPS for Effects (with- or without- being attached to SimObjects or MDLs) which might allow greater control over distance-based conditional display ? :scratchch

Just some well-intended observations and speculative ideation (...and I don't yet have P3D to test at this time, either).:duck:

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well after reading all that i didn't find the answer of my question ( i didn't post it yet )
i want a taxiway edge light effect
i want it to be visible from a distance of 3000m so pilots can find the taxiway
anyone can help me with a script ?
( i use my own texture 1024 x 1024 the light is in the middle )
thnx in advace


Resource contributor
Have you taken a look at my Airfield Lights Toolbox (AFLT) at Navigate to User Applications / AFLT and click the Development Release menu item. The new version, 3xxx, can give a range of up to 10 nm using 3-plane, LOD variable size lights and almost that far with effects using inverse mipmaps.

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