variable resolution terrain?

[pilgrim]

Hi,

  I was wondering if Terragen or Terragen2 will be able to create a
terrain (in WAVEFRONT .obj format) where there is high resolution in
one area (smaller polygons) and low resolution in the rest of the
terrain (bigger polygons).  I'm doing a Mars descent landing demo and
I was hoping to generate a big piece of terrain that has high
resolution where I will land and low resolution elsewhere.

Thank you,

Linh
PS  I am still working with the SGI so my terrain polygon count can't be to huge.
     If Terragen can generate Mars like terrain, do you know of any nice Mars terrain
     on the internet I can use?  Thank you.

[bigben]

I've used multiple TER files for two projects now and it's a piece of cake if you can accurately create the TER files.  I use GlobalMapper to generate 2049x2049 TER files of increasing resolution with the same centre. My Tetons project uses terrains of 20, 40, 80, 160 and 320km wide... and my Grampians project has data to include NZ and New Guinea.  Once you have the terrains it's just a case of laoding them into Terragen from largest to smallest, with "Flatten surface first" checked in the displacement tab.

See this post for some extra info on blending at the borders of the terrains.
http://forums.planetside.co.uk/index.php?topic=1232.msg12367#msg12367

[Oshyan]

Good advice Ben, however I think he was more interested in variable resolution on export as geometry, for use in other applications. Unfortunately TG2 doesn't currently support any resolution adjustments for geometry export and only exports terrain in LWO format for now. i would suggest a decent workflow would involve using multiple resolution .ter (or other) terrain files and converting them to geometry in some other application, for example Daylon Graphics' Leveller. L3DT and World Machine will also offer geometry export in upcoming versions, although I'm unsure whether either will include geometry optimization.

- Oshyan

[ProjectX]

Theoretically you could do the animation in TG2.

The only problem would be if you needed to look at the sun in-animation, while in outer-space (it be seriously ugly), or if you needed particle effects.

Of course, you'd also have to purchase Deep + Animation, but then if you're planning on using these terrains commercially in any way, you'd need to purchase Deep anyway.

[bigben]

PS  I am still working with the SGI so my terrain polygon count can't be to huge.
     If Terragen can generate Mars like terrain, do you know of any nice Mars terrain
     on the internet I can use?  Thank you.

Forgot the PS.

3DEM will convert Mars Mola data which is available at:
http://pds-geosciences.wustl.edu/missions/mgs/megdr.html

These will look very Mars-like 

You could create multiple resolution files, load them into TG and then Export in LWO for subsequent conversion.  I'm not sure if that would use the actual resolution of the terrain or would have a fixed resolution for the entire file. If it's the latter you'd have to combine them some other way.

As a worst case scenario you could split your renders using multiple versions of the terrain with some overlap of frames and then fade between the segments or:

Theoretically you could do the animation in TG2.

The only problem would be if you needed to look at the sun in-animation, while in outer-space (it be seriously ugly)....

You could replace the sun with a sphere (with an image map or other surfacing) if this is a problem.