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

Subject: Re: [geometry] 3D box -> 3D multi_polygon conversion
From: Mateusz Loskot (mateusz_at_[hidden])
Date: 2013-06-12 05:13:54

On 12 June 2013 08:15, Adam Wulkiewicz <adam.wulkiewicz_at_[hidden]> wrote:
> 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.

Thanks Adam, that's whole lot of explanation for a 3D newbie.

Regards,
--
Mateusz Loskot, http://mateusz.loskot.net