Thanks for the answers !
Oshyan wrote:
> What is the source of the data and what size of real world area does it cover? What is the size of the source file(s) in MB/GB?
original DEM data is about 2 billion samples at 32 bit floating point precisison (plus material/texture layers) so we are talking
about around at least 4 but up to maybe 20 gigabytes file size.
As most of the big 3D programs apparently are not yet 64 bit ready, I wrote my own 3D software tool suite in C++ for processing the DEM data on my 64 bit hardware (Windows Vista 64, 12 Gig RAM).
With this software I am able to do basic raycasting renders and geometric transformation of the large DEMs.
However, although my program already handles the basic 3D tasks, I really would like a specialized Program like Terragen for the final production visualization render/shader pat of the project to take advantage of the many advanced shader features and presets/plugins that I don't want to re-invent from scratch ;-)
So the idea is as follows: For each render I would first generate a view-dependent triangle mesh (TIN) that only contains the triangles necessary for the current view at the current level of detail: this would be "only" around 100 Million instaed of the original 2 Billion polygons.
So all I need would be a possibility of importing a (sufficiently large) *irregular* triangle mesh into Terragen.
I have already installed the free trial version and read through the manuals and Wiki but I only found the possibility to load a *regular*
DEM as the initial height field into Terragen.
But although I didn't find it in the docs yet I'm sure there must be a possibility to simply import an arbitrary triangle mesh into TG.
If so, what would be the maximum size of the triangle mesh ?
Would it be only limited by the available machine address space (i.e. 2-4GB on 32 bit platforms) ?
bigben: your work sounds very interesting and I'm certainly going to read through it in more detail.
However: from the first look at it it seems that you are using nested/tiled hierarchies of *regular* grids, right ?
Actually this is similar to the processing chain of my original DEM software (which also handles nested grid pyramids to cover
terrain from 200 kilometers down to sub-meter scale)
What I would like to do is to generate a s maller, temporary view dependend sub-model of the large grid hierarchy outside of terragen first, which could then be imported for rendering views in Terragen.
This sub-model would, however, not be aregular grid any more but rather a highly irregular spaced triangle network.
Thanks again everyone for any answers,
eps.
