Geometry Boost List: Re: [geometry] 3D box -> 3D multi_polygon conversion

Subject: Re: [geometry] 3D box -> 3D multi_polygon conversion
From: Adam Wulkiewicz (adam.wulkiewicz_at_[hidden])
Date: 2013-06-12 03:15:38

Hi,

2013/6/11 Mateusz Loskot <mateusz_at_[hidden]>

> On 11 June 2013 21:12, Adam Wulkiewicz <adam.wulkiewicz_at_[hidden]> wrote:
> > MultiPolygon concept to describe 3D mesh is a good idea. I'd rather
> provide
> > additional concept.
>
> I'm no expert of 3D, but isn't there a better concept for 3D mesh storage,
> without redundan vertices and edges, perhaps less topologically fragile
> than
> multipolygon? (I'm just curious).
>
>
Of course, typically 3D geometry may be stored in various ways. There can
be a set of points/normals/tex_coords but more often geometry is stored as
coordinates buffer + index buffer - indexes are defining polygons, which
typically are triangles. And in the case of triangles we have a few
possibilities. They can be defined as a seqence of triangles (3*N indexes
or just points to define triangles), strip (2 + 1*N indexes), fan (1 + 1*N
indexes).
And this may be a definition of a SubMesh which some number could be stored
together to form a Mesh. There even could be one points buffer for a Mesh
and SubMeshes could only store indexes + operation type. Idealy the concept
would define that.

Regards,
Adam