TransDEM Forum

Hi All,


I went through the process of making a DEM last night and while I was successful, I was not as happy as I was hoping to be with the final results of the WMS process and 2D Map Tiles. I found both too fuzzy. I'm hoping to have the most crispest images possible for both the ground textures and the tiles themselves. I know I do not run the most modern system, but I'd like to believe I could get something decent looking out of what I have.

Info that might be of use:
Hoping to port this to TANE. Use an AMD 6850 1 GB Vid Card (a dinosaur, yes I know), Win 7 64 8GB, AMD Phenom II X4 965 quad core |3.4 GHz CPU
I would like to use MS Virtual Earth, zoom of 20 (1:1100)
Using Toporama as my WMS source.

I know there are also limitations in terms of what I can do with this data in Trainz, but I feel like I do not know enough of transDEM to get the best out of it and would love to get the best possible results of course.

My question is, what fine tuning should/can I do to ensure I get the best looking ground textures/tiles when I export the route to TANE? I've looked through the manual and I see functions I can tweak, such as Map Size Width Height (pixels) for the WMS function and Map Size: Width and Pixels for Tiles but I am at a loss at what I could tweak, given what I have. I might also be tweaking things that have no effect or make things worse as well. :/

Advice is always appreciated!


Mr. Gisa

I get the best ground images so far from d/l actual maps off of the usgs site and then cropping and opening I had to crop my Cheyenne side of my Salt lake city to Cheyenne route more than I wanted to as tane didn't want to import the file size and in order to make sure I got all the area were the route was I ended up downloading 887 maps I also use dems from the usgs site that are 1 arc second found I get a lot crisper valleys/river/mountains

Thanks for your advice RoadWarrior104. The DEM I am making is in Canada so I don't think I could use the USGS stuff even if I wanted to...

There are many factors to consider. The following are just rules of thumb:

• Since ground textures are sharper on the 5m terrain grid, I nowadays create my entire route with the 5m grid.
• 1:24000 resp. 1:25000 is the maximum scale to fully resolve the maps on the 5 m grid. Anything larger should go to UTM tiles.
• Orthoimages as ground textures should always use the orthoimage texture set.
• For UTM tiles enable maximum texture size 4096 pixels. (Unfortunately, T:ANE compresses them which significantly reduces sharpness.)
• Zoom level 18 for orthoimages appears to be a reasonable compromise between detail and amount of data.

Thanks for your advice Dr. Ziegler. In the past, I used Toporama for the textures/WMS and MS Virtual Earth as my map tile provider. I can see that things have changed! Based on what I am reading here and based on what I am reading about Toporama (http://www.nrcan.gc.ca/earth-sciences/g ... maps/16842) am I correct in reading that their smallest scale is 1:50000? If so, does that mean that these textures should go to UTM tiles instead? In that case, do you know of an alternative to Toporama for a better quality (e..g 1:25000 scale WMS provider?). If I made the textures with tiles, could I also use the MS Virtual Earth data I have acquired on the tiles as well?

For orthoimages, is it like painting MS Virtual Earth/Google Map tile information onto the terrain itself?

Lastly, assuming data is not a concern, would zooming up to a higher level give a better result?

Thanks again for your advice.

Mr. Gisa

You mean 1:50000 being the largest scale? It's the quotient that matters. 1:50000 is greater than 1:250000. 1:50000 is fine for 10 m ground textures and shaper, of course, on 5m ground textures. 1:25000 or 1:24000 would be the limit for any ground texturing. Ortho-images, when used as a navigation aid, usually have a much larger scale, 1:5000 and up. That's why the need to go to UTM tiles. However, when their purpose is to serve as easy and convenient backdrop texturing, they can also go ground textures but would need the custom aerial image texture set, with no grid and much better colour matching at the expense of the number of textures involved.

I haven't seen a 1:25000 top map on the Geo-Gratis servers, so I can't give you advice here. Open Street Map may have much more detail in many areas, but lacking that detail elsewhere, and it's not a topo map.

Even with the custom textures in place, you still get the same resolution, 1 pixel per 5m or 1 pixel per 10m. The custom textures advantage is their colour accuracy which you don't need for maps, but they can do nothing for sharpness.

Map tile maps are usually limited. Zoom level 16 is maximum, I think, for OSM. Ortho-images may go much higher but have to examine them first, whether the data source is really up to the nominal scale available. A higher zoom level also increases the amount of data you deal with. Each level up quadruples the size. Due to the sheer masses of data you encounter at the higher zoom levels I would be rather careful here.

In the end, you have to run tests yourself to find out what works best for you. Take different map sources, play with ground textures/terrain grid and UTM tiles, preferably 3D, and compare the results.

Thanks for your reply Dr. Ziegler. I appreciate the guidance you have given. I have been playing around with some various settings as I'd like to get everything looking the best I can before I do any work on any route. I'm just glad it is not a big one...

Mr. Gisa ^^

Sorry to bother you again Dr. Ziegler, but I've tried numerous ways of exporting map tiles without what I was hoping for and I'm getting frustrated because I'm sure I can get better quality map tiles in TANE and I just cannot find out how. Sometimes, pictures are better than words. Here is what I can see through transDEM:



MS Virtual Earth, zoom 19 (I'd prefer 20 but I can live with this). This data is in a relatively urban area and should be consistent. I assume Map Size has no relevance here on the sharpness (just the size of the actual map itself).

When I get the data for these images and try to export them into TANE, I get something that looks like this:



I know there are limitations and that I might not get something that looks like the first picture but what settings should I use/can I use? to export those images to get closer/the closest to what I'm seeing in the transDEM preview window into TANE? I assume that the UTM tile Object size has no relevance in terms of sharpness. Would I get a sharper image by adjusting the Max. Texture size?

I apologize again for asking more questions, but I feel like I am going insane trying to get these images into TANE and I'm pretty sure it is possible, right?

Mr. Gisa

The maximum texture size plays a role indeed. With most graphics cards you can safely set it to 4096 these days. That's also the maximum Trainz supports. TransDEM will pick a suitable size dynamically, depending on image scale. For better quality you can also switch to 500m UTM tiles. That duplicates resolution (and quadruples size). Nominally, this allows 1 pixel per 10cm. However, you still may find the end result disappointing in T:ANE because T:ANE applies texture compression when importing the UTM tiles with Content Manager. And you cannot turn that off.

Thank you again for the reply.

I run an older card (AMD 6850) but I do know that when I put in 4096 textures, it did not crash in TANE, so it must be working. I think it came out the same in that sense, but I will try it out later on at that setting. I'll also definitely try the 500 m UTM tiles too. Thanks for the tip! No worries about TANE doing what it does (that's nothing we can control).

Take care!

Mr. Gisa