Why does Bryce slice up Terrains on export?

TapiocaTundraTapiocaTundra Posts: 268
edited December 1969 in Bryce Discussion

I was wondering why Bryce sliced up terrains on export to exactly 21845 polygon parts.
Discovered this from a thread over in the new users help forum.

Bryce Terrain to 3DS


  • HoroHoro Posts: 8,648
    edited December 1969

    From where do you export the terrain? In the Terrain Editor, you can set the resolution.

  • TapiocaTundraTapiocaTundra Posts: 268
    edited December 1969

    Hi Horo, thanks

    Yes I understand by setting the resolution in the terrain editor the mesh within Bryce becomes denser and more detailed, on export however in the export terrain window we will always be given a mesh with 7938 polygons to start of with no matter what resolution has been set.

    The noticeable difference is when we adjust the triangulation in the export window the mesh becomes denser at larger increments the higher the resolution setting "a sure way for me to crash Bryce on my machine by the way:)"

    What I really want to find out is why the exported 3DS file is always sliced into 21845 polygon sections and grouped.

  • HoroHoro Posts: 8,648
    edited December 1969

    I've tested this, using a default terrain and exporting with 99458 polygones as 3ds. When I open it in Wings3D, I see the slices you report. I get 5 slices with 21,846 polys, 33,041 edges and 11,197 vertices for 4 of the 5 slices. One slice is smaller.

    I've exported the same terrain with the same settings as Wavefront obj. Importing it in Wings3D I see only one object with 99459 polys, 149,633 edges and 50,176 vertices.

    This slicing up and grouping is probably due to the 3ds format or how it is implemented in Bryce. I've never noticed this because I usually export the terrain as image - 16-bit greyscale.

    If you can use the Wavefront obj format in whatever application you import the terrain, I suggest that you use obj. It has the benefit of saving either the mesh, the material applied to it, or both.

  • TapiocaTundraTapiocaTundra Posts: 268
    edited May 2012

    Hi Horro
    Thanks for taking the time.
    Maybe I should have done a little more research.

    .3ds file format

    the magic number of triangles is 65535 and not 21845 Bryce divides the mesh by 1/3 of maximum and groups so that it works.

    Post edited by TapiocaTundra on
  • HoroHoro Posts: 8,648
    edited December 1969

    @TapiocaTundra - thanks for your reply. I should have looked up that Wiki page myself.

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