A Beautiful Panorama

Started by dhavalmistry, October 17, 2007, 11:12:55 pm

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cyphyr

Can you get UK data, I've always found it next to impossible without paying an arm and a leg.
Richard
www.richardfraser.co.uk
https://www.facebook.com/RichardFraserVFX/
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Ryzen 9 3900X @3.79Ghz, 64Gb (TG4 benchmark 6:20)
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bigben

Quote from: RArcher on October 19, 2007, 11:55:08 am
I'm thinking that putting together an animation of the full 7 day canoe route (starts and ends in the top left corner of the map) might turn out rather well.  Of course that depends if I can manage to surface things to look nice enough.  The great thing is that there are plenty of reference photographs on the web to try and get the trees and lake sides correct.

I'm just loading all the data I have in GM now to see if I can figure out your export process.


For the lake mask all I do is set the shader to a slope shader (I think it ignores any lighting, but turn it off just in case) and then export a 24-bit RGB tiff with the same settings as your terrain. 

For the terrain there's a bit more planning of coordinates to give terrains of the right size and overlap. Technically it doesn't really matter, the only crucial piece of information is the coordinates of the centre or one corner of the terrain so that you can calculate the offset. Working with UTM projection (primarily to remove a lot of distortion) throws everything into metres by default which makes it very easy to get the units you need for TG.  I use a database to do all the brain work for me.  If you have the data I can attach a text file with the coordinates I use for the terrain set as an example. Then you don't have to download the TER files.

The matching landsat images are really helpful for distributing trees as well as lot's of other stuff. Some exmaples I've done include the NZ orbital renders I'm working on at the moment and the Tetons images.  The full resolution images are roughly the same res as this terrain data.

Quote from: cyphyr on October 19, 2007, 01:08:51 pm
Can you get UK data, I've always found it next to impossible without paying an arm and a leg.
Richard


I have the same problem here in Australia. Maximum free resolution is SRTM3. There's an election coming up in a few weeks.... maybe I could ask my local candidates??  :D

bigben

Damn.... left the files at home (forgot to transfer them to my USB drive).. will have to be tomorrow...

bigben

I've posted a provisional set of files. The canoe theme stuck with the filenames  ;)

http://www.path.unimelb.edu.au/~bernardk/terragen/terrains/canoe/files/

While I say they're provisional, that's only referring to the supporting images which are ridiculously large at the moment as they were just a quick export.  The base terrain will remain unchanged. It's a 4097x4097 terrain, the total width is included is the number in the filename.

Full resolution for this data set is set to 15mx15m. The landsat data is marginally higher, and the DEMs are around 14x23m metres with this projection. The slope map is at this resolution. I'll also release smaller versions for the other terrains but you can always use this to crop a region and calculate it's offset. There's also a small version of the landsat image scaled back to 4097x4097. Don't try inserting the images into TG at full resolution.. just to save you a bit of time.

File sizes are a bit big, but using other compression methods either don't gain that much, or reduce the quality which makes working with them much harder. My own files are all LZW compressed TIFF, but the max. quality JPEGs are much smaller and still work OK since the original data has JPEG artefacts in it anyway.

I would have added the other terrains but I made a booboo in the numbers and they don't overlap... duh.... There will be two side by side terrains providing roughly 100x60km at full resolution in the centre of this terrain.  Keep an eye on the URL for new files... or you'll see an announcement in the file sharing section when the set has been completed.

PS. I was also going to play with georeferencing the map... handy for reference and could be interesting blending from map to TG surfaces.

dhavalmistry

what is the use of slope map and how do I use it???...its pretty large for a map....
"His blood-terragen level is 99.99%...he is definitely drunk on Terragen!"

bigben

I use the slope map for 2 things.

1: Creating a mask for lake surfaces.  Magic wand in PSD, tolerance 1, no antialiasing. Lakes surfaces are white, anything not flat is not white.

2: Guide for drawing/selecting rivers.  Landsat images are not exactly aligned on the terrain and if you blindly trace over a river for creating a mask you can end you with rivers running up along the sides of gorges.

I'll probably throw a lake mask in with the high res panoramas anyway as these do compress a lot..

bigben

See... I told you they compressed a lot.  The zip contains a very quick lake selection and basic lake setup. 90x90km.  Once again very quick selections used and not verified as actually being lakes, but in 10 minutes that's a lot of lakes in a 90x90km area.... (and part of a river).

The screen grab is a good sample that shows how it is usfeul for drawing rivers.  As this is based on your actual terrain it's more accurate than using the landsat images.

Enjoy.

bigben

Fixed the other two terrains. I'll post them when I get back to work.  Apart from getting some interesting terrains and a *lot* of extra data to play with, setting up the TGD for this tiled terrains showed up a flaw in my function mask.  It worked as long as the terrains didn't overlap more than the blending margin. In this case they did, which resulted in a sharp differentce in altitude along one seam.

It took me a little while to figure out what went wrong, but in the end is was simply a negative value in the blending mask as the result of subtracting one mask from another. This was easily fixed by including a clamp 01 node after the subtract node.

So here are two sample renders. The first shows the extent of the full resolution terrain (and why this is such a popular canoe route.... that's one very big lap of the mountains  ;)

The second shows some alpine lakes near the northern edge of the lake mask I posted... Just testing out the resolution of the terrain and the mask accuracy. I'm going back to my New Zealand masks for a while. This should be enough to keep you busy for a while.  I'll post some more Canadian terrains later now that I have the full set of elevation data (some 12,000 files).

Enjoy

dhavalmistry

thank you Ben.........

just a question....can you not use a slope mask to distribute population.....more accurately???....
"His blood-terragen level is 99.99%...he is definitely drunk on Terragen!"

bigben

Quote from: dhavalmistry on October 23, 2007, 11:33:43 am
thank you Ben.........

just a question....can you not use a slope mask to distribute population.....more accurately???....


Yes..... and No.

My tree population masks can get relatively complex. It comes down to a process of combining a number of different components that make up the final distribution of trees.  From the landsat images I usually just create a boudary for the main tree population. This is then merged with other shaders to provide the variation in density within that region.

It's worth including this component as it provides a reasonably realistic distribution of trees based on the actual distribution taking other factors into account that cannot be derived from the terrain alone (geology, roads and man made features, agriculture, forestry etc...).  The USGS also provide canopy density data which, while low resolution, provides a useful starting point.

Other factors for masking include slope, altitude, direction of slope/sun, distance from camera, subtraction of other masks (e.g. lakes/rivers) and so on.  This is one reason why I normally end up with parallel node networks, 1 for surface shaders, 1 for mask components and 1 for mask combinations. You might look at a render and think "Why bother?" but when you look at a render of a region you know very well it's really amazing.

Now stop reading this and get the rest of the files I posted  ;).  (included a landsat image with increased compression to drop the file size, the 2 new terrains and a TGD linking all 3 terrains and the sample lake mask)

Enjoy  ;D

dhavalmistry

"His blood-terragen level is 99.99%...he is definitely drunk on Terragen!"

bigben

OK.. may be a weekend job. I think that side is only 25-30m, but that's still a lot better than SRTM3

dhavalmistry

ya sure....no hurry...take your time....
"His blood-terragen level is 99.99%...he is definitely drunk on Terragen!"

bigben

November 05, 2007, 04:49:38 am #43 Last Edit: November 05, 2007, 06:12:01 am by bigben
Melbourne Cup this week.... long weekend   :P

Posting the terrains when I get to work in the morning. I'm making a 15 and 30m version, although the 15m data stops along the ridge to the west of the valley  :(

Here's the coverage of the 30m terrain and a sample render with 15m data to the right of the ridge and 30m data to the left

bigben

Quick URL for now... tidying up later.

http://www.path.unimelb.edu.au/~bernardk/terragen/terrains/banff/files/

2 terrains, full res landsat and slope map, tgd merging terrains.

Enjoy  :)