Heightfield basics (Tiles & Bulging)

[Tudor]

Hello
I've gone through the tutorials and they don't seem to touch on a few items that I'm personally struggling with regards to heightfields.

1. When I add a height field it is always added above the surface below it vs. merged with it.  This causes a 'bump/bulge' to occur which makes adding a flat water surface to certain lake basins within the affected area impossible.  Is there a solution to that?

2. I had a 0.5GB shape file with topo data within it that I had to export as a 4x4 set of tiles as my computer could generate a single file without crashing the software.  When I pull those into Terragen 3 I have tried checking off Georeference as well as Auto Georeference from file.  Neither one does what I would expect which is to retrieve the geo coordinates from the file and place them in the appropriate 4x4 grid.  Manually placing them is practically impossible with the number of updates I'll be adding not feasible.

Would someone mind helping struggle through one or both of the above listed issues?

I've included two of the GeoTIFFs I'm using in the hopes that someone can see if I've screwed things up.

As always I expect it to be user error and will be pleasantly surprised if it just requires a tweak or two. 

Regards,
Tudor

ps. Forums can't handle the files so I pushed them up to Google Drive
https://drive.google.com/folderview?id=0B1ajUHaaZm_Galg2RXAwU2htWGM&usp=drive_web#grid

[Dune]

In the heightfield shader node there's a 'flatten surface first' check, did you apply that? Or you can mask the heightfield by an inverted (simple) shape for the masking of the procedural terrain.

[Tudor]

Yes I have that checked off.
It seems to be connected to the fact that the heightfield object is trying to blend with the environment around it ... which makes sense. 

What I'm noticing is that if I generate a terrain and then add the 4x4 tiles they are not all set to the same height and I can't seem to adjust their vertical position (which makes sense but would be nice to be able to do)
Maybe what I need to do is generate a single unique flat area that I can place all of the heightfields on top of so that are all at the same height.

I think I might also need to generate a ring of fake land that goes around my 4x4 which is allowed to 'blend' into the generated landscape around it.  The streaking that occurs when I try and blend the current tiles sticks out like a sore thumb.

Tudor

[RArcher]

The files you've uploaded work fine here.  Try these steps:

1. Add Terrain > Heightfield (load DEM) or Add Terrain > Heightfield (load multiple DEMs)
2. Choose the four files either one at a time or add them all at once
3. Change the Apex at lat/long field in the Planet 01 node to be approximately where your georeference co-ordinates are located ( 65.4, -96.8 )
4. Change the Border Blending in each heightfield shader to be 0 instead of the default of 0.1

You should end up with something like the attached image if you move your camera around a little bit.

[Tudor]

In your example the files seem to be overlapping.
Is that you doing that or is that the tiles getting positioned that way?
Do you set all of the files to the same georeference point?

[bobbystahr]

In your example the files seem to be overlapping.
Is that you doing that or is that the tiles getting positioned that way?
Do you set all of the files to the same georeference point?

Not good with this stuff myself but I'd assume that's the way they load following RArcher's explanation

[bobbystahr]

In your example the files seem to be overlapping.
Is that you doing that or is that the tiles getting positioned that way?
Do you set all of the files to the same georeference point?

It might be better if you uploaded your failed .tgd to the forum which would allow close inspection of your method for errors by the high foreheads in this area to examine.

[RArcher]

Terragen will read the co-ordinates embedded within the geotiff files and align the tiles properly to line up.  You should not be changing any of the geo-referencing information within Terragen.

[Tudor]

Terragen will read the co-ordinates embedded within the geotiff files and align the tiles properly to line up.  You should not be changing any of the geo-referencing information within Terragen.

I tried importing "Multiple DEMs" and the below screen shows the screen I used to do that.
When I hit Load Files the program just returned to a blank original setup and showed no sign the files had been loaded into the main view.

They are appearing in the Network view but I'm unclear how to make them appear.

Any help would be appreciated.
The files are quite large (35 at about 5-6MB each) so I'd rather not have to upload unless there is no other choice.

Tudor

[Oshyan]

If Georeferencing is enabled, then the files are probably displaying in an area that is far from your current camera view. You can either disable georeferencing (if you don't need the terrains to be all located at the right location on the planet), or move your camera to where they are shifted to by the georeferencing. You can start to move the camera to the general area by right-clicking in the 3D preview and choosing Center on Object or Shader and select one of the DEMs you have loaded. Depending on where on the planet they are georeferenced to, the camera may end up inside the planet, so you may have to work a bit to get it onto the surface, but it will certainly help get you to the right general area.

- Oshyan

[Tudor]

So I just can't seem to get this to work.

The files if pulled in on their own seem to work if I use the height multiplier but when pulled in as a set of tiles they don't appear to be visible.
I've tried disabling the default terrain and warp shader in the hopes of seeing the tiles.
I'm not convinced the copied coordinates I took off the tile and attached to the camera was correct but I'm not seeing anything.
Any help would be greatly appreciated.

I've uploaded a subset of the tiles as well as the Terragen file.
https://drive.google.com/file/d/0B1ajUHaaZm_GNERjMWw4OWVRLTg/view?usp=sharing

If you could take a look and let me know what I've messed up I'd really appreciate it.
Tudor

[Tudor]

Has anyone had a chance to look at the file?
Is there something odd or obvious I'm doing in there?
Tudor

[Oshyan]

To find the terrains I right-clicked and selected "center on" and picked one of the terrains. The angle was a bit odd, but easy enough to rotate to get a decent position. Then I disabled "Flatten surface first" in all of the heightfield nodes and they appear to stitch properly to me. This setting should maybe be disabled by default when importing tiles...

So try this attached TGD and see if that's doing what you want.

- Oshyan