Importing Maps from Google/USGS/Live.com, etc.

[thinkstorm]

Dear all,
I found some tutorials how to import USGS maps with microDEM and HOG. However, HOG does produce the right height maps, but does not produce any lines on the map itself as a drawing guide.

Is there a trick? am I missing something? Do I need to add a custom texture in the creator?

Cheers, T.

 

[geophil]

Hi thinkstorm,

if you are planning a US route and want to use HOG go for TIGER data. That's presumably the easiest way. Some of the online map services - not USGS topop maps but the vector based road maps - are difficult to use because you have to find proper coordinates.

And you cannot use Google Earth imagery with HOG. It has coordinates but would yield a totally blurred ground texture. The ground texture is limited to a resolution of 1 pixel per 10 meters which is not good enough for GE images.

If you want to stick with HOG look for "Base Maps" or "Basemap" to find texture carrier objects as ordinary 3D assets. You can apply Google Earth images to them but you are responsible for correct scale and proper georeferencing. There is also MapMaker but I haven't heard of anybody using Google Earth with it (and it's limited to 3 arc sec SRTM DEMs). And there is TransDEM which is payware.

geophil

 

[Jerker]

G'day thinkstorm,

Geophil has failed to mention my preferred option in this area - Global Mapper (http://www.globalmapper.com). Like TransDEM, however, it too is (ahem) payware but well worth the expense.

Jerker {}

 

[geophil]

Yes, I didn't mention Global Mapper. As far as I know it has powerful georeferencing capabilities. So do some of the GPS mapping tools which gained popularity over the past couple of years. However, I am not aware that any of these tools has a Trainz back end. So, while these tools will provide valuable aid at a certain stage in the process they only partly alleviate the task of feeding HOG manually.

More important than the tools, however, are proper coordinates right from the beginning. As said before, many of the road map web sites do not not forward them to the end user.

geophil

 

[thinkstorm]

Ok, I will look into that. I thought one could create a topology map with HOG using microDEM or other tools. Then I would use something like gmax to produce a (ok, huge) mesh, project google earth images on it (or microsoft live or whatever), and have that mesh half transparent over the baseboard (it actually has the exact same shape as the baseboard). I can then lay down my tracks and later delete the mesh again.

I don't know gmax at all - is there a limit in terms of size TRAINZ can deal with - or texture size? The HOG data is just not very accurate, though it does give a rough sense...

ON that note: do you actually survey the tracks in order to get the heights of bridges or trestles right? The Richmond, VA system has lots of higher trestles along the river, and I am looking forward to design the highway bridges (switch to "Bird's Eye View" on the Junction of 195 and 95 South)


Thanks for your input, cheers, T.

 

[geophil]

Ok, I will look into that. I thought one could create a topology map with HOG using microDEM or other tools. Then I would use something like gmax to produce a (ok, huge) mesh, project google earth images on it (or microsoft live or whatever), and have that mesh half transparent over the baseboard (it actually has the exact same shape as the baseboard). I can then lay down my tracks and later delete the mesh again.

Those meshes already exist. One instance is called "Base Maps". You provide the texture, i.e aerial image. You also have to provide proper georeferencing and scale.

I don't know gmax at all - is there a limit in terms of size TRAINZ can deal with - or texture size? The HOG data is just not very accurate, though it does give a rough sense...

I apply either 1024 x 1024 pixel textures or, depending on scale, 2048 x 2048 pixels. The latter my not work on all graphics cards.

HOG created terrain can be quite accurate, if you use the HOG-private 24bit format. It depends on the original DEM. I would go for 1/3 arc sec NED and download in GeoTiff or another format which supports floating point elevations.

ON that note: do you actually survey the tracks in order to get the heights of bridges or trestles right?

With 1/3 arc sec DEMs (10m) you won't normally need additional surveying.

geophil

 

[thinkstorm]

Thanks for the pointers, I didn't find the right Base Maps with my first quick Googling

With 1/3 arc sec DEMs (10m) you won't normally need additional surveying.

I actually meant the height of bridges / trustles over ground. I went around with a laser distance meter today and took some measurements - and I almost got arrested! Homeland Security keeps watch, they declared me nuts on the spot when I pulled out my laptop and showed them my preliminary data model.

The police officer was pretty interested in MicroDEM, though.... at this point I knew I should've made a Donut & Coffee shaped route.

Anyway, there is no law against surveying bridges (as long as you don't step onto the tracks), however, HS doesn't really care (Win a free vacation at Guantanamo Bay - no thanks!).


T.

 

[leeferr]

You're really lucky that they didn't confiscate your laptop to investigate. In today's post 9/11 world, depending on what part of the country that you're in, you have to be really mindful of what you're photographing, sketching or surveying. I assure you that some authorities can get really uptight about it, especially around critical infrastructure such as bridges.