ryanbatcund

Is my overlay not working (see pic)?

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Looking at this image...  This is ZL16 with custom ZL18 3km perimeter around my home airports.  Is there a reason why some trees are all over the industrial areas that have buildings?  Some of the overlay seems to be working, the houses along roads are correct, and there is a neighborhood off in the distance (circled in green) that's normal etc.  Is there a problem using the mixed overall 16 then doing perimeters in higher ZL's?  Or is there another explanation?  The OSM data isn't present in those locations?

overlay.jpg

 

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It's a thing, with z16, Ryan.  On my first experiment with the entire Island of Cape Breton, I did it in z16, with overlay...and frankly...well...it looked like...well...frankly...

I then completely re-cut all the tiles and upgraded to z17/19...and had a wow moment, where all the forestry had a sort of '3D' texture, and yet I knew was 2D.  The problem with z16 and lower, is that the element resolution is very low...and that lends to blurrines, and non-well defined visual elements, not suitble for low VFR, to less than 12,000 feet.  Some would say it is good much lower, but...one has to totally respect that opinion, as always. For myself, my opinion, VFR and less than 12,000 feet operation is the domain of z17 and up.  

What z16 (again...personal opinion in play...) looks good with, where the mind can not see the blurriness of the texture (comparing it to z17 and up...), and then a crisp auto-gen sitting on top of it, that totally shows the lower detail as compared to z17 and up, is to NOT have an Overlay generated upon z16.  I have been doing 'filler' tiles in the U.S. of A. that sit between my well-traveled z17/z19 combo tiles, that look really good for that relaxed, in-between high level FL flight, whether commercial, or recreational.

Of course, I don't have night lighting, or XP active roadways, upon those tiles, but...in reality, I don't do night flights for hours upon end. I do night flights at 2,800-5,500 so I can enjoy the XP platform detail of those night roadways, streetlights and road traffic, head-lights and tail-lights.  So..that is not a problem. I fly those routes between late dawn, and early evening, before XP would kick into 'light' mode.  What is the result?  Looks great...the z16 saves generating time, and storage expense, and at FS180 up...looks world-plausible, real. I compared z16 at the start of the FL's...to real world photos...and it is at least 80 percent veritus, as it looks. So...that has been my M.O.  Looks good...on high level,  transcontinental flights, and as I come into my arrival and landing zones, I have two choices...I can keep my Z16 tiles that have Z19 2KM's airport surrounds, without XP overlay elements, OR...(and anybody can do this...Ortho4XP is such a powerful, well-though out program!) you can merely at a later date, yellow-highlight that particular tile that holds your destination, or departure airport...and take the 1 minute, that's all it takes, or less, to generate an overlay for that tile.  If you have a linked or short-cutted representation of your yOverlay Folder, inside your Custom Scenery Folder, you are good to go...XP10 or 11 will see that new Overlay for your z16 tile(s) that you just created, perhaps a week or ten, past the original generation date of that particular tile. Another little trick, if you want to fly over ANY tile without overlay, and just see the really nice and crisp z17/z19 (if you generated at that zoom factor) is to merely take out the yOverlay Folder 'short-cut' and place it onto your Desktop.  XP11 will then squawk at you, that there are no overlays for ANY of your tiles, and will not crash, but the Ortho will be the generated tile (that's what you want for this flight!) but with no XP roadways, lights, street-lights, road traffic) but..you WILL see roadways, highways, suburb roads, rural roads...but as 2D..part of the actual photo-to-conversion process, and they look good, quite frankly!  So Ryan, you have many choices of how you wish to work/manipulate visual ortho with Ortho4XP generations.

Bottom line, if you have stuck it out with me ....is that  if you want to enjoy the beautiful realism of orth-scenery...the captured picture-what's-really-there elements, that the mind has no problem defining and accepting as virtual, you need to generate at z17 and above.  If storage is a serious factor in any ortho decision, than z16 it totally satisfactory rather than NOT having ortho at all.  z17/z19 (two KM airport surrounds) is the absolute visual sweet spot.

Here's a recommendation.  Take a favorite area you fly over...and create FIRST, with a zoom factor of z16 with overlay.

Go fly over it...from rotate, to a VFR common range of 2,800 feet to 7,500 range, and eye-ball it.

Then....re-cut that same tile with z17/z19 (two KM's airport surround) and fly the same heights.  Ryan, you be the judge.  Fly over rural, suburban, forestry, infrastructure within the overlay, crispness of detail held, below the auto-gen that now matches it, and you be the final judge for your particular visual wants/needs/requirements.  I think you will see what I am talking about. z16 is great for the FL's..but not so, truly (can be used of course), but not so truly for VFR departure and arrivals. It can be 'there' for rapid ascent 1,500-1,800 FPM) climb-outs, as for commercial, you are not outside the aircraft, joy-riding, but inside where one should be...monitoring the flight progress IFR.

Hope any of this helps your enjoyment factor. :) Of course, anytime we post, it is through the lens of personal opinion and meet's/requirements. As always, any reader of such content, will, or will not necessarily agree with that content.  An important disclaimer, for all of us, reading upon forums.

Cheers,

Mitch 

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I get this all the time, specially around New Orleans.    It has something to do with the OSM data/Overlay import not meshing together properly.   The texture and mask part of the tile have no data on them, just the texture.    It doesn't know a building from a forest.  The OSM/Overlay Mesh data source have to be defined properly and fixing OSM data is beyond my abilities.   I would ask this question in the Ortho forum on the ORG as they have several experts, including the creator, chime in often on anomalies like this and how to fix them.

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This issue of misplaced trees is probably the biggest problem with using ortho scenery and autogen.  It's also a problem when using w2xp scenery - trees growing out of buildings.  The ZL of the tiles has no bearing on the problem.

I'm not an expert, but the fact is forest placement from X-plane's global scenery overlay or even the HD mesh overlays is not very accurate in relation to the real world.  It's approximate at best, although accuracy does vary in different areas depending on the OSM data.  Another issue is when Xplane generates residential autogen it also generates trees in and around the houses.  These trees  spill over into areas where there are no trees in the real world.  Even the residential autogen is not accurate sometimes being generated in industrial, commercial and rural areas.

Adding custom W2XP scenery (not from SimHeaven - you need to generate your own) with carefully defined smart exclusions does help to reduce this problem.  The only other solution, to my knowledge, is to add forest exclusion and in some cases residential exclusion zones using  overlay editor.  I have been improving some of the areas I frequently fly in by doing this, but it is time consuming.

If a developer could find a way to accurately place trees in Xplane on a large scale, I would be most willing to pay for the addon. A similar project is being worked on for FSX, Prepar3d and FWS that uses an algorithm to interpret the orthophotos and generate data to accurately placing trees and houses, right down to the color of the roof.  You can see more at https://forums.chrisbelldesigns.com/topic/268-secret-project-unveiling-vearth-virtual-earth/

Hopefully something similar will find its way into Xplane.

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Just to chime in here guys, the default scenery/HD mesh does not use OSM data for forests, if it did, the US would be mostly void of trees or anything else. The only thing that comes from OSM are the roads.

In most cases, the data has come from some other source, you can find a list here http://www.alpilotx.net/downloads/x-plane-10-hd-mesh-scenery-v3/#Data-Sources-Acknowledgments . 

The forest data is normally generated along with the mesh from raster images to generate landclass. This is an approximation as it isn't 100% accurate and mostly low resolution compared to a forest traced in OpenStreetMap or some other source. It looks fine when used with the default textures, but when used with photoimagery, the issue is evident, ie. You may see trees, but the outline won't be accurate.

Getting good data, especially for the US is a real challenge. For Massachussets, you can try Mass Pro: http://forums.x-plane.org/index.php?/files/file/32447-massachusetts-pro-vfr-scenery/. This will add accurate buildings and forests, but it may be too heavy on some systems, especially around Boston.

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.......but if you fancy flying in the UK just to see what can be achieved then Tony's GB Pro places all the forests and copses accurately (and every building, wind turbine etc). Still get the odd hiccup with trees in odd places but overall the difference is immediately and significantly noticeable.

I hadn't flown in the UK for a few months and just came back to it last week and it was one of those wow moments  - everything pretty much fits perfectly with the orthos. 

Tony - hats of again to what you provide for us!

 

cheers

Peter

 

PS Tony - I see UK2000 are starting to be converted for XP11

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Tony already gave the correct infos.

And I would like to repeat it - because it seems to be one of the most often repeated misconceptions:

  • Forests and most of all other landclass related data (in scientific terms landclass is almost never used, but rather "land cover" for natural stuff and / or "land use" for human based stuff) IS - mostly - NOT FROM OSM! Exactly for the reasons Tony noted ... because in this area OSM is lacking for a big percentage of the planet surface (but the global scenery - and similarly HD / UHD mesh - intend to cover big, contiguous areas).

What comes from OSM (to extend on Tonys point) is:

  • roads
  • railroads
  • power lines
  • all water features ... like rivers / lakes / coastlines (one exception is Canada, where I / we replace OSM data with data from CanVec .... because OSM has partially(!)  included CanVec , but is very patchy and makes some places look bad)
  • Building height information (where available) to induce high risers / sky scrapers in the right location in the autogen.
  • some, very special "land use" data, which is hard to come by (but this is only mostly stuff like industry areas, land fills, mining ... things like this .... oh and glacier infos too .... but really nothing of the "natural" stuff like forests etc)

The used forest data in the landcover is nevertheless more accurate than many might think (as this kind of data is available at relativel high res from many projects). It is easily available at the current overall resolution of the landcover data, which I put now around 60-70m resolution. Of course, this is still far away from the sub meter per pixel photo imagery, but nevertheless captures a bit larger forest patches accurately. Also, this forest data is usually not some "made up" data, but based on scientific projects which derive forest info from relatively high res sat imagery.

Finally, for forests the mesh resolution is relevant to (at least when we talk about default / HD / UHD Mesh). The reason is, that the scenery generator Laminar and I use is aligning the forest overlay with the mesh under it (to make forests align with the final textures nicely) ... So, if the mesh is lower res, then the forest overlay will be lower res too (even if the raw forest landclass was high) ... Thus, HD and even more so UHD Mesh can not only give better elevation detail but also (and very importantly) much more detailed landclass representation and this - in the end - much more detailed forest representation.

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By the way, for those who want to understand (and even more users are asking this same question around the net) the forest topic in X-Plane in more detail, I have wrote an in-depth post on this topic over at the ORG:

I hope it helps to clarify a few things :smile:

 

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