Ticket #71 (closed defect: fixed)

Opened 4 years ago

Last modified 18 months ago

Terrain: Pan function looses Terrain resolution in XCM files

Reported by: rob@… Owned by: max
Priority: high Milestone: XCSoar 6.0.x
Component: Terrain Version:
Keywords: Cc: ziarko@…

Description (last modified by Turbo) (diff)

XCSoar 5.1.3 and 5.1.4

The new XCM file are great b/c there are fewer and smaller files. However,
there is a problem with the PAN function where the display loses terrain
resolution.

This can be demonstrated running on a PC in simulator mode, but also FLY Mode
and affects PocketPC3.0.1 on IPAQ Model 3995.

I created an XCM file w/ 6 arc-second resolution approximately 240 s miles wide
and 200 s miles high (XCM file is available if needed) for Allegheny Moutains
in NE USA.

When I start XCSoar (either Sim or Fly), and enter PAN ON mode, and then PAN
Left, after about 60 s miles west from "home", the terrain resolution drops
dramatically, and even if I zoom in, I can not see the details of the terrain.
I'm guessing that the resultion drops to about 100 arch seconds. It affects
north, south, east, west panning.

However, if instead of panning, I let the simulator to "fly" west for 60 s
miles from "home," it correctly shows the higher resolution terrain for the
same area, so it does not appear to be a data error.

Work-Around: If I concurrently load both the XCM file and the older style 6 arc
second .DAT terrain file of the same region, the problem with the degraded
terrain resolution in PAN MODE does not occur. This avoids the clutter of the
topology files, but requires more file space.

USE CASE: when a pilot would want to "look ahead" of where he is going to
examine the terrain options using PAN. In this scenario, he might not be able
to see very much terrain detail.

Attachments

Alps Map - resolution issue.png Download (77.5 KB) - added by ziarko 19 months ago.
Example of low & hight resolution mixed.
Alps Map - resolution issue 2.png Download (77.4 KB) - added by ziarko 19 months ago.
Example of low & hight resolution mixed ALSO IN FLIGHT

Change History

comment:1 Changed 4 years ago by jwharington@…

This is a known issue. Because at the higher resolution afforded by the xcm
files with jpg2000 compression, we can't have all the terrain loaded into memory
at full resolution; so a set of tiles around the glider at full resolution are used.

In the future I'll allow the screen center to also load its own tile so that
when the panned area is far away from the glider, the terrain will still display
at full resolution.

comment:2 Changed 2 years ago by Turbo

  • Owner changed from scottp@… to jwharington@…
  • Status changed from new to assigned
  • Version 5.0.9 Beta deleted
  • Type changed from defect to enhancement
  • Milestone set to Release 6.0 Alpha

comment:3 Changed 2 years ago by Turbo

  • Summary changed from Pan function looses Terrain resolution in XCM files to Terrain: Pan function looses Terrain resolution in XCM files

comment:4 Changed 2 years ago by Turbo

  • Component changed from Map to Terrain

comment:5 Changed 22 months ago by Turbo

  • Description modified (diff)
  • Milestone changed from XCSoar 6.0 to XCSoar 6.1 (wishlist)

Changed 19 months ago by ziarko

Example of low & hight resolution mixed.

comment:6 Changed 19 months ago by ziarko

  • Cc ziarko@… added

All,
it is not only in PAN mode. I am getting a mixture of high & low resolutions also during the fly. An important Alps area is impacted. See picture attached.

Tomek

Changed 19 months ago by ziarko

Example of low & hight resolution mixed ALSO IN FLIGHT

comment:7 Changed 19 months ago by ziarko

All,
My second screenshoot shows this issue being apparent also in flight and not only in PAN.
Observation:

  • depends where you start - the low resolution area is always the same. You can see it in PAN but if you fly there - it will be also broken.

An example:
If I start in Fuessen - area of Pinzgau is in low resolution.
If I start in Mayerhofen (that is in Pinzgau) that Pinzgau is OK but areas further to the east is broken

Hope it helps.

Tomek

comment:8 Changed 19 months ago by ziarko

  • Type changed from enhancement to defect
  • Milestone changed from XCSoar 6.1 (wishlist) to XCSoar 6.0

comment:9 Changed 18 months ago by max

  • Owner changed from jwharington@… to max
  • Status changed from assigned to accepted

comment:10 Changed 18 months ago by max

  • Status changed from accepted to closed
  • Resolution set to fixed

Fixed in a47f73466dc30addaa76f565fffab4a30fb1c2fd

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