two .ter and two aerial images

Started by AlanR, December 05, 2015, 03:27:12 pm

Previous topic - Next topic

AlanR

I have looked, but cannot find a simple answer, at least I think its simple, have 2 terrain files from GM and 2 aerial images from GM one of an area 10*10kms and 1@ 1*1km at much higher resolution, and it is inside the larger area, I can combine the terrains fine, but struggling with the textures, so the higher rez texture  shows up over the top of the lower rez one, any pointers appreciated
cheers

Dune

It doesn't sound too complicated, and should work if you add the high res texture after the low res as child of a surface shader or new (masked) surface shader. So what is your setup like if it doesn't work, and what happens exactly?

AlanR

Im no terragen expert, so I may have gone about it all wrong, my experience in 3d tells me that I am doing something wrong,  the two terrains are all in correctly, one lying on top of the other in the correct position overall. what I cannot understand at the moment is the connection of each surface shader to the correct terrain and what tells terragen how to place the shaders, am missing something fundamental I think. I have tried just loading the textures, firstly, adding a surface layer and adding 2 children (image map shaders) I have also tried 2 surface shaders, none worked.
cheers

Dune

December 07, 2015, 03:02:20 am #3 Last Edit: December 07, 2015, 03:04:58 am by Dune
The image map shaders should have the same parameters as the terrains in principle. The image map shader should of course have plan Y checked, the right measurements, and then should appear over the hills.
It even works if you add the smaller under the first image map, then as child of a surface shader. You can use 2 displacement shaders or use the same and change color paramaters in the image map shaders. For a quick setup I used the same image maps for displacement, which is obviously not good with my 2 random chosen maps.
Here's the idea.
If you don't want the second image map displacements on top of the first (when using 2 displacement shaders), you may want to mask the area of the smaller map out of the first (by a simple shape the same size into the mask input), if you know what I mean. If you use one displacement shader for both maps, I guess the lower image map overrules the first anyway.

AlanR

Thanks for the info, I think one problem I am having is when trying to place terrains from osgb36,(flat) have converted to geographic but then get ugly artefacts on the edges, I understand that terragen is not written to understand all projections, but struggling to get a straight forward workflow for terrains we have surveyed, cleanly, I will have to carry on importing them with no geo reference (matching their relevant positions, but for a landscape viz software, this is an area that needs addressing, as not all of us use USGS data :)
cheers for all your help though :)

Oshyan

Texturing is generally handled as a layer stack applied over the entire planetary sphere, not (by default) as a *per terrain* process. So you do not literally apply one texture to one heightfield and another to the other. Instead you apply the one you want to show as your base layer first (higher in the Shader network), and the one you want to show on top second (lower in the Shader network).

For the GIS data issues, have you experimented with any of the border blending or smoothing options or anything? Can you show an image of the artifact you're seeing? What is the source of your data, is it publicly available for us to test ourselves?

- Oshyan

AlanR

Hi Oshyan
Yes tried nearly everything I can think off, image attached, also get terracing on the landscapes on nearly every format, but this has not happened all the time, so I think I have just done something different, but the edges are bad

Dune

That's obviously a matter of border blending (0.05 or so).

Oshyan

Indeed, Border Blending may help. Of course it does "lose" small (adjustable) amounts of data at the edges. The alternative is to display the edge of the data just as it is, basically, but triangulated in the render process so you get these very long triangles at the vertical edges. If you're seeing "spikes" or other issues with the data really being represented incorrectly, that would be something else.

We'd really want to see a data sample to test ourselves, ideally. If that's something you can provide (under NDA, etc. if necessary), you can send it to support AT planetside.co.uk

- Oshyan