Rainer, I have these artifacts also with Global 2010 Ultimate. Been searching for answers without success...

Is it possible to patch this?

 

With best regards

Rainer

 

Holy smokes! Yeah, that's patchable! Looks like there is a few bad pixels in the NASA source data there. I'll have to take a look when I get home!

Rainer, I have these artifacts also with Global 2010 Ultimate. Been searching for answers without success...

 

NASA must have missed this area in SRTM3 as well. Well, we'll clean it up. Adding it to my todo list for the next patch. There is somewhere around 300-400 tiles, each 36001 pixels by 36001 pixels, so there is about 500 billion data points in FreeMeshX. It's a lot of data to work with.

 

Even at a hypothetical 99.999% accuracy rate, that leaves around 1 million bad pixels scattered throughout the world.  Now the real accuracy rate is probably even higher, but we'll work to find anomalies and correct them as we go along. Free of charge!

Daniel,

 

thank's for the quick and positiv answer!

 

regards

Rainer

but we'll work to find anomalies and correct them as we go along. Free of charge!

 

That's pretty bloody impressive and remarkable in this age of paid everything! :im Not Worthy:

Hi Daniel,

 

first, many thanks for your huge and  generous effort. It adds a lot to most regions.

 

Sadly, there are some more or less strong artifacts that seem to have different reasons:

 

(1) "no data" cells in the SRTM source that is coded as -32768 m altitude. I found several small ones in N Poland in the N50E010 tile causing deeep holes that can be surrounded by high spikes when the mesh resolution in FSX is set to less than 38 m (which comes from the way FSX interpolates the altitude data when using a higher mesh resolution than the actual bgl files has - they seem to use some kind of bezier function which overshoots at very steep cliffs). These should be easily detectible and can be replaced by the value of surrounding cells. I hope this can be automated with your geo tools?

 

(2) perfectly linear ridges of some meters altitude in north-south direction along the boundary of the one degree source tiles. They seem to become prominent mainly in the flat lowlands - there are some in N poland near the baltic sea that are very easily visible. The cure for these problems that can be found in other of your bgl files too is not so obvious to me as it depends on your workflow. I would suggest to open each 10x10 degree bgl file in TmfViewer and inspect them with a medium zoom factor. These lines and also data holes (in a deep pink) should be easily visible.

 

(3) very narrow plateaus of 500 m altitude near the Oder river (already reported by Rainer) for which I have no idea how to detect them easily and what is their cause.

 

I will see if I find tomorrow the time to check all bgl files of the Europe package which is the only one I downloaded. If such problems occur in most tiles I suggest it might be better to disable the torrent and other download links for now to prevent unneccessary traffic before these faults are patched...

Hi Daniel,

 

first, many thanks for your huge and  generous effort. It adds a lot to most regions.

 

Sadly, there are some more or less strong artifacts that seem to have different reasons:

 

(1) "no data" cells in the SRTM source that is coded as -32768 m altitude. I found several small ones in N Poland in the N50E010 tile causing deeep holes that can be surrounded by high spikes when the mesh resolution in FSX is set to less than 38 m (which comes from the way FSX interpolates the altitude data when using a higher mesh resolution than the actual bgl files has - they seem to use some kind of bezier function which overshoots at very steep cliffs). These should be easily detectible and can be replaced by the value of surrounding cells. I hope this can be automated with your geo tools?

 

(2) perfectly linear ridges of some meters altitude in north-south direction along the boundary of the one degree source tiles. They seem to become prominent mainly in the flat lowlands - there are some in N poland near the baltic sea that are very easily visible. The cure for these problems that can be found in other of your bgl files too is not so obvious to me as it depends on your workflow. I would suggest to open each 10x10 degree bgl file in TmfViewer and inspect them with a medium zoom factor. These lines and also data holes (in a deep pink) should be easily visible.

 

(3) very narrow plateaus of 500 m altitude near the Oder river (already reported by Rainer) for which I have no idea how to detect them easily and what is their cause.

 

I will see if I find tomorrow the time to check all bgl files of the Europe package which is the only one I downloaded. If such problems occur in most tiles I suggest it might be better to disable the torrent and other download links for now to prevent unneccessary traffic before these faults are patched...

 

You're welcome!

 

Good feedback! I can address some now before I take off for home.

 

1) No data cells. It may be that we overlooked some tiles that have no data cells inside. The only time I encountered these though were in the CDED datasets for Canada, in which we manually filled in. I've encountered a few spikes before, but never a concentrated area in our testing. All no data values should be filled in by NASA, but perhaps they overlooked some areas. These can be filled in easily though.

 

2) That I have not seen whatsoever. I'll have to examine this carefully later tonight, because that would be quite obvious. The mosaics were made with GDAL, and they take into account the geotransformation systems and georeference systems of each tile when they do the merging process. I've doublechecked to make sure the data is contiguous between tiles in my tests. I check the flat lowlands you described though.

 

3) Yeah, unfortunately artifacts like these are still present in the SRTM source data, although they have improved from v2. We'll try to get as much as we can.

N50E10:

 

Ah, I see that weird thin line now.

 

Oh, I see now. These holes are not NASA related. I had used a few of Jonathan Ferrenti's data tiles (terrain connoisseur) that were 30-m resolution of the N50E10 and N50E20 tiles, and it turns out (surprisingly) that his terrain tiles do contain some data holes, and are probably the source of spikes and voids in Poland. I had used his tiles because I was very impressed with his Norway tiles (which are not SRTM based; I think these are), and had opted to use his data for N50E10 and N50E20 tiles thinking the quality would be quite good. I had also used a few of tiles for certain Alp areas. I may have to revisit those. Well, after looking at the NASA SRTM 3.0 data directly instead, the voids go away. I believe the plateaus and spikes near the river will be solved as well. Lesson learned. Should have stuck with NASA for this area.

 

Another patch will be issued soon to solve the holes. The lines though. I never had noticed them until actually zooming in in Tmfviewer. I wonder if it's related to Jonathan's data.

 

 

Edit: Well, while there are lines in TMFviewer, but there is nothing to indicate that in the sim, after a cursory look. Here I am in the Baltic lowlands, right on that supposed line. Interesting.

 

 

Guys, fantastic product. Just had to do a complete reinstall of my sim and being in P3D I believe the order of items in Scenery Library is opposite to FSX. I installed Innsbruck and had artifacts floating in mid-air. I moved the mesh to the top (priority 1) in Scenery library and the scenery was fixed, and looked fantastic.

 

Is this the recommended setting?  ie move the mesh to the very top of priority?  Would this have any effect on VAS?  Thanks in advance

As I suspected, the artifacts in the Poland and Baltic tiles are a result of erroneous Ferrenti data. Replaced them with corrected NASA versions. No data zones and artifacts removed. Relatively isolated problem.

 

Before:

 

 

After:

 

 

 

Patch 1.02 coming soon!

Guys, fantastic product. Just had to do a complete reinstall of my sim and being in P3D I believe the order of items in Scenery Library is opposite to FSX. I installed Innsbruck and had artifacts floating in mid-air. I moved the mesh to the top (priority 1) in Scenery library and the scenery was fixed, and looked fantastic.

 

Is this the recommended setting?  ie move the mesh to the very top of priority?  Would this have any effect on VAS?  Thanks in advance

 

It doesn't have to be at the very top, but at least move it above other lower LOD meshes, such as the default terrain for sure! It shouldn't affect your VAS any differently than let's say the stock USA mesh.

Hi Daniel,

 

I found another "no data" hole in the N50E020 tile at N57,03 E29,28.

 

Concerning the ridges following the degree boundaries, I can assure that they are visible in FSX in some places - please see the linked image. In this case the ridge is some 50 m higher than the surrounding terrain. It though may depend on your FSX terrain mesh settings (I have mesh_resolution=22).

They are often more prominent in TmfViewer due to the simulated oblique lighting in the viewer. I suppose that they are more visible in FSX at low sun angle in spot view, when even small hills or ditches cast shadows. Another case where it could be visible is along the 28 and 29° boundary in the N50E020 tile. Sometimes they are ridges, sometimes trenches of some 40 m depth.

 

Those linear faults seem to come from the way your software stitches the 1 degree SRTM tiles together. Maybe some interpolation parameter ca be changed?

 

I'd suggest to check the other tiles for faults before offering a new patch.

 

https://drive.google.com/open?id=0Bw8Pa2ZosQcwMTkzYWlIY04zWmc&authuser=0

Hi Daniel,

 

I found another "no data" hole in the N50E020 tile at N57,03 E29,28.

 

Concerning the ridges following the degree boundaries, I can assure that they are visible in FSX in some places - please see the linked image. In this case the ridge is some 50 m higher than the surrounding terrain. It though may depend on your FSX terrain mesh settings (I have mesh_resolution=22).

They are often more prominent in TmfViewer due to the simulated oblique lighting in the viewer. I suppose that they are more visible in FSX at low sun angle in spot view, when even small hills or ditches cast shadows. Another case where it could be visible is along the 28 and 29° boundary in the N50E020 tile. Sometimes they are ridges, sometimes trenches of some 40 m depth.a

 

Those linear faults seem to come from the way your software stitches the 1 degree SRTM tiles together. Maybe some interpolation parameter ca be changed?

 

Yes, Meerkat, I did come across one of those degree boundaries! I must have flown along the wrong meridian before. This is an artifact of Jonathan Ferrenti's terrain data not "meshing" well with the NASA SRTM 3.0 data. Perhaps the mosaic was trying to interpolate something screwy at that tile.

 

The new patch 1.02 for this area with the NASA 3.0 data fixes all of the river artifacts, no data zones, and these weird ridges. I'm not sure why Jonathan's data is messed up in this area, but works fantastic for Norway.

 

I'm checking other areas in Europe outside of these two tiles, but I'm not finding any similar anomalies. It looks to be an isolated problem with an easy fix.

Want to thank you for providing us with an outstanding Central/South America mesh.  After installation checked out a few places in Colombia which I know very well in real life and was very pleasantly surprised by the accuracy of the mesh, something I never experienced before in this continent with previous payware mesh.

 

Regards

Patch 1.02 coming soon!

 

What a tempo ..............

Very good news.........thank's.

 

Rainer

Very nice product thank you very much !!!!  Do you wish to know about things that don’t look quite right?

 

If you fly from Papua New Guinea from Jacksons AYKP runway 320, turn heading about 325,  after about 30 seconds you come across a lake that’s elevated.  Not sure what is causing this, all I have installed for this area is FTX Global.  I have tried to upload picture but failed miserably . Regards

Steve

 

Very nice product thank you very much !!!!  Do you wish to know about things that don’t look quite right?

 

If you fly from Papua New Guinea from Jacksons AYKP runway 320, turn heading about 325,  after about 30 seconds you come across a lake that’s elevated.  Not sure what is causing this, all I have installed for this area is FTX Global.  I have tried to upload picture but failed miserably . Regards

Steve

 

 

I took a look but I didn't see anything except a river, and it looks right to me. Do you have FTX Vectors? It corrects the elevations for a lot of water bodies so that they work better with more accurate meshes like FreeMeshX or FS Global. This is probably why I don't see any problems.