Reproduce the correct elevation in Gazebo
Opened this issue · 3 comments
Hello,
I successfully followed the tutorial. I extracted from terrain.party an area with a good elevation
In their output, there is written:
The original elevation models for this area contained elevations ranging from
58 through 1508 meters.
These elevation values need to get transformed into a grayscale images. This
section describes how that translation was done in this particular case.
These heightmaps were adjusted such that 58m (actual) is equal to 40m in
game. All other elevations are relative to that.
Again, the lowest point in these height maps is now 40m in game; all other
terrain is even higher. You will likely want to adjust the water level as a
result.
One other gotcha -- the area selected for export here has an exceptionally large
range of elevations. These real-world elevations were compressed into the
available range of in-game elevations, which will makes things appear flatter
than they are in reality. This is unfortunate, but there aren't a lot of great
alternatives; C:S only supports 1024m of elevations in total.
I scaled the images as indicated.
Actually, even if I can see a difference, nothing seem a big difference such as 58 m vs 1058 m.
Moreover, if I try to put in the terrain a rover (estimated dimensions: around 1 metre max) it results as high as the highest hill! So, it is not realistic. I attached a picture
Can you help me, please?
Hello,
If you are following the tutorial in this repository, the terrain.party program is designed specifically for a video game, and isn't necessarily the best choice for generating accurate terrains in Gazebo. I just used it as an example in the tutorial because it was the most hassle-free way to get topographical data that I knew about. It may therefore lead to some weird results.
That being said, I haven't experienced any problems with it like what you are experiencing, so I'm interested in what's happening. Where in the world is this terrain data from?
Hello Matthew,
thank you for your return. It is possible a similar scenario, in fact.
The area of the picture comes from the south-east of haiti :-)
I tried the same with the Himalaya, including the Everest mountain area , but the result is similar.
I got the point, it is meaningful. Maybe other data sources (such as QGIS) can return more appropriate results for gazebo. I tell you updated!
Did you try this program?