First of all I want to say that almost a year I am using OpusFSX and for me this is by far the best addon in its category. But only, I would say, irregularity occurs when there is reduced visibility reported on destination airport. Is that so often mentioned FSX limitation, my OPUS settings or something else. To be clearer, I attach screenshots and OPUS Weather file. I paused FSX, done screenshot and copied OPUS Weather file when screenshot is taken. My OPUS version is 3.34.0.

 

Take a note of distance from Destination Airport (in this case CYYC) and reported visibility. Same was on 20 miles from destination.

 

 

After couple of miles everything was as reported (Same weather file)

 

 

My Opus Settings

 

 

And OpusWeather file as attachment.

 

 

Thanks in advance!

Not sure what you are reporting here. The reported vis obviously applies to the surface layer and not necessarily the vis at your current altitude. As you descend you will enter that poorer vis layer and FSX will render it.

Is this a case of FSX not being able to take into account lower vis layers when rendering views?

Because that is what appears to be reported here. As you approached you were flying in an improved vis layer at a higher altitude. FSX will assume this vis applies everywhere, all the way to the ground and above it, that's because the sim has never been able to render or take into account vertical vis changes when rendering the scene.

As you got nearer you also descended no doubt until you entered the lower vis layer giving poorer vis and that's what FSX rendered, again assuming that vis setting extended everywhere.

This process would continue until on the ground which would match the surface vis layer.

Generally the vis is layered upwards and improves as you climb into better vis layers. Those boundaries have to occur someplace and they will normally be aligned at lower levels with cloud bases or inversions. I would advise you reduce your default surface vis down to say 48km, that would help give you poorer vis at lower levels and also help reduce the sudden changes slightly when climbing and descending.

Looking at your settings I would also advise you adopt more of the defaults and then always specify your Destination and Max Cruise Altitude (unless you do not wish to use GRIB data that is).

The Default Surface Visibility should be reduced though.

I will have a look at the vis layering see if I cannot raise the lower altitude boundaries, but just as in real life the boundaries are made to coincide with cloud layers and inversion layers so there may not be much leeway.

You should also refer to the Visibility Weather Map just in case you were flying into an area of poorer surface vis. That would also explain why the vis dropped as you approached your Destination.

Stephen

 

Please note, the visibility surrounding the aircraft cannot be controlled in real time or specified to FSX. The weather and all appropriate visibility layers are injected into the sim and FSX renders the vis in accordance with the targeted visibilities, again only taking into account the current visibility and not considering any poorer vis up ahead or at lower levels.

 

Nothing can be done about this, its not really possible to just extend the surface vis to much greater altitudes as the vis has to improve at some level so its best to try and match nature. The Surface Visibility Weather Map will show you how the surface vis is smoothed and interpolated. This smoothing will also improve or graduate less with a lower Default Surface Visibility setting.

 

Stephen

Thank You Stephen for fast and detailed answer. The thing that I reported here is that: "How can I see airport from 16-30km if vis on this airport is 14km?. In other words: How can I see you if you can't see me? But from your post I understood that is FSX vertical vis rendering problemm. Is it so hard or impossible to put some layer in 20miles ahead and 4000-6000 feets below if metar reports lower vis in this area (IF x < y THEN z)?

 

Thanks for tips about my settings. I allways set Destination ICAO an Max Cruise Alt, but I forgot that screenshot. I also tried Default Surface Vis set to 48km but in this case I don't liked "all that white around me" especially on high altitudes when CAVOK reported and expect to see far in distance.

 

Nermin

We are talking about FSX here which has never factored in any poorer vis layers beneath when considering the visibility slant range. As I said, FSX assumes the current visibility extends everywhere and does not consider the visibility up ahead or beneath you.

The 48km setting is far more realistic and yes it does reduce the visibility at lower levels, so you can't see forever when flying at low levels. We could barely see 20 miles at 3000 feet the other day and that is quite typical. But if you didn't like the reduced vis at 4000 feet when you set a default 'surface' vis of 48km (which probably meant you had a minimum of 64km at your altitude) then you would hardly like it if I created a duplicate surface vis layer of just 16km (10 miles) between 4000 and 6000 feet for your approach !

Once again, FSX has its limitations and these must be accepted. Its best to have realistic improving visibility layering at higher altitudes rather than to just extend the surface vis unrealistically all the way up to 6000 feet.

Don't get confused over statements such as CAVOK, or 9999, or 10SM in the METARs. These Vis OK indications do not mean unlimited visibility and they ALL refer to surface visibility. Unrestricted surface visibility indications of 9999 or 10SM really mean at least 10km at the surface, or at least 10 statute miles at the surface. Good enough for pilots not to be concerned over any reduced visibility. These and the CAVOK statement do not mean you can see forever at higher altitudes either. We had CAVOK last week but could still only see 20 miles at 4000 feet, probably improving to 30 miles at 8000 feet, hardly seeing forever, but it was still CAVOK.

Stephen

I think there was a misunderstanding. I would like to see (if it possible) reduced vis in lower levels, to be more precise,  to see in what I'm flying (descending) to - in this case to see low vis layer in front of me - in which later I will enter- like I see clouds ahead, without sudden occurrence. It such as we can see cloud only after we enter in, but not before.

 

Something like this (in our case we see all below until we cross the border of upper and lower vis)

 

 

 

 

I'm sorry if I bother you, and thanks for all help.

 

Nermin

Clouds yes you can see, hence we include fog and mist effects to make fog and mist layers beneath or ahead of you visible. Visibility layers up ahead or beneath you cannot be seen, FSX cannot render anything but the current visibility it is in and the visibility cannot be controlled in real time or in any fashion, only the visibility layers can be specified and left to FSX to render.

 

Stephen

 

The picture you show is a fog bank not a layer of 10 mile visibility. I'm sorry but you will have to accept FSX has limitations.

 

Stephen

OK. Thanks for your patience. And I have to say once again: Opus is the best for me and I recommend it whenever I can.

 

Cheers

Many thanks Nermin, I only wish FSX could handle such visibilities.

 

The new version of P3D does include volumetric fog effects but that again won't help render areas of lower vis up ahead or below you, it will only render fog (vis <= 1000m) and hopefully a bit of mist, depends when they use the volumetric effect.

 

Opus already injects all the vis layers coordinating them both horizontally and vertically across the 800 x 800 mile weather map. Its up to FSX or P3D to actually render the vis and neither are capable of handling true vis, considering areas of poorer vis, if they could you would see inversion layers just as in the RW.

 

Best Regards

Stephen :-)

I found an interesting screenshot (not mine) as well..

 

(screenshot from VATSIM fb page)

 

I find it relevant. That layer is not solid and does look like a fog. How could this be achieved in FSX? Just to add that i love Opus and i do find it revolutionary. I always mention this in my posts. It's my first post about Opus on avsim though. Just to make sure that i'm not whining or something.. Just wondering if i could help in making Opus even greater?

 

Best Regards,

Victor B

 

Edit ... This could most likely be Opus weather. Just enable the fog and mist effects, its always been there. Stephen.

OK. Thanks for your patience. And I have to say once again: Opus is the best for me and I recommend it whenever I can.

 

Same.

 

It isn't "just" the product, though. It's support like this (never condescending, always teaching) that makes it an extremely easy buy.

You will find plenty of shots like these on our SimForums Screenshots.

 

Even some on our website.

 

As I said this is fog or mist, NOT slightly reduced visibility areas. Just enable the fog and mist effects which tops all areas of fog and mist with a thin layer of stratus. In other words you are seeing cloud.

 

Stephen :-)

 

http://www.opussoftware.co.uk/opusfsi.htm

 

Just go to the bottom of the web page. You will find loads of OpusFSX weather pics like this all over the web. Opus has always been better and improved !

 

Opus has been renown for doing this sort of thing from day one !!!

 

I recommend the FEX soft and natural cloud textures as well.

 

Stephen

 

You will also find a section called,

 

OpusFSX Live Weather mist and fog effects

 

http://www.opussoftware.co.uk/opusfsi/gallery.htm

 

Just click on the screenshots to enlarge them. I believe there are also plenty of screenshots showing these OpusFSX weather effects on forums like OrbX etc.. As I said above there is no need to add this effect we have been doing it from day one !

 

Stephen

If I understand correctly we must have vis<1000m (fog) to see this stratus layer below. Can it be placed always (on the edge of lower and upper vis) when reduced vis reported below. (Again: IF vis < some_value THEN put_stratus_layer) You can make option for user to choose if he want to use this 'effect' or fake fog simulation. It does not matter how we call it: cloud or something else, point is that we don't see ground from above.

 

Are next scenarios correct:

 

We are in the plane at 6000 feet 12 miles from airport.

 

1. Airport  reported visibility is 900m -> stratus cloud layer appears and we don't see airport

2. Airport  reported visibility is 5000m -> no stratus cloud layer and we see airport with slightly reduced visibility

 

I understood when you said "Visibility layers up ahead or beneath you cannot be seen, FSX cannot render anything but the current visibility". I say: place stratus cloud above this area when you look in it from distance.(if reported visibility is smaller then distance). Let FSX to render cloud if it can't render "anything but the current visibility". 

 

Maybe it is not perfect, but for me is the worst when I see all from above and suddenly I don't se anything.

 

Tnx again!!!

 

Nermin

Once again you canot see visibility changes (this is a well known FSX limitation, FSX has never accommodated 'seeing' through or into areas of poorer visibility). You can see cloud though hence our Fog and Mist effects.

 

OpusFSX has always, right from the very start, provided options for Fog and Mist Effects, these are set within the Weather Preferences dialog. These options top layers of fog (surface vis <= 1000 metres) and mist (surface vis <= 6000 metres) with a thin layer of either overcast or broken stratus cloud, thereby making these areas visibible from above.

 

All the numerous screen shots you see depicting Opus mist and fog patches show how, with the right stratus cloud textures installed, how effective this can be within the sim.

 

But cloud rendering also has its limitations within FSX. No weather engine can alter or set the cloud transparencey, nor can any engine position individual clouds, nor can any engine select specific cloud textures (FSX does that using the limited cloud texures available). FSX also has limitations in the rendering of the clouds, minimum thickness, providing appropriate cloud coverage when requested etc..

 

So the bottom line, weather engines have no control over the exact postioning of these 'pseudo' clouds, and have limited control over the overall appearance of such cloud. Especially when trying to include a very thin and low lying layer of overcast stratus, something FSX has always stuggled with or not rendered correctly (hence the need for the Opus Low Overcast Effect).

 

Furthermore, a line has to be drawn somewhere and at present it has been drawn with surface visibilities of 6000m or less (i.e. mist). This is after all a 'pseudo' cloud, it is a cloud layer that has been added by the LWE, not a cloud layer that has been reported by the Met station, and with any visibilities greater than 1000m such a cloud WOULD most certainly be reported.

 

All cloud layers are significant. Topping fog and mist banks is one thing, it is quite handy to know or have an impression that they are there (even though the Destination Weather Report should tell you exactly what to expect) but just adding cloud to top areas of haze (surface vis <= 12000m) is another thing. Such cloud would most definitely be reported in any METAR statement and considering how FSX renders (or fails to render) low lying cloud might be be anything but realistic, and I question how useful it would be.

 

Fog and Mist are important to pilots, surface visibilities of 12km are not so important, and if you set a realistic Default Surface Visibility such false effects would not be necessary.

 

That said I will consider adding a 'Haze Effect' to the current Fog and Mist effects. This is not something that I would be particularly fond of myself, because it is moving away from realism and more into the realms of a game. Haze simply does not generally have a sharp edge, in summer months it can simply result in much reduced visibility up to higher elevations (something you do not like).

 

The reduced visibility is a far more realistic effect and is what the OpusFSX LWE already does ! But you have already indicated you do not like such realism in your sim flying, for example you did not like my suggestion of setting a 48km Default Surface Visibility (in Europe, at this time of the year, I actually set 32km). If you do not care for this natural reduced visibility, even though that is most likely to give you the most realistic effect and make you aware of the reduced (hazy) visibility that lies beneath and around you, I suppose an added haze effect may help.

 

But once again, my recommendation to everyone is to set the Default Surface Visibility to a more realistic 32km or 48km and accept that in the real world, especially at this time of the year in the northern hemisphere, you can and will encounter quite poor vis at heights of 4000 to 6000 feet.

 

As I said, I will consider adding the Haze Effect, but I will have to experiment and convince myself that FSX can render something that is both useful and different from the already more useful Fog and Mist effects. After all, 12km visibility means the Vis is OK as far as pilots are concerned. You are just making these commonplace surface visibility changes more severe and noticeable by setting a very high Default Surface Visibility giving you better than expected vis at 4000-6000 feet AGL.

 

Stephen

P.S.

 

The version 2 Prepar3D does include volumetric fog effects. I don't know if there is any user control over these effects, such as setting surface visibility limits for the effect. If there were then this would obviously provide the optimum solution as all areas of surface visibility less than the user specified limit would become visibile.

 

I will experiment with FSX and investigate whether a Haze Effect would add anything to the LWE.

 

Stephen

As of late I have had some fantastic low visibility and haze effects with OPUS. Last night coming into Denver with 0.7 miles and overcast at 300 feet looked about right. I think the cruise haze seems to be better now that the cirrus level has been adjusted to change altitudes. Looks 10 times better.