This is never actually used in practice, is it (by people who are familiar with the alternatives, at least)?
motoole2
@jfondrie Even though it might be strictly worse than other representations in terms of storage cost, ability to access neighboring polygons efficiency, etc., it is still the simplest representation of geometry.
To test out the representations used in current 3D modeling software, I created and exported a mesh with Blender and looked at the RAW file values. Several of the exported file formats (e.g., .OBJ, .DAE) define the mesh in terms of an adjacency list which saves a bit on storage requirements. Surprisingly, even though the .PLY files can also represent geometry in terms of an adjacency list, the .PLY file that Blender outputs is a polygon soup, where any particular vertex is listed multiple times.
So clearly, this format is at least sometimes used in practice. :-)
Tdog
Why are the triangles in the first rabbit gapped? Even with a polygon soup you should be able to store the vertex coordinates such that their edges are aligned.
elenagong
I think the first rabbit shows how it is divided into pieces by the triangle cloud...?
crabbage
I think it's really cool to be able to understand how meshes are encoded, because a few years ago I opened a 3d model file in sublime text and was blown away by how almost-readable it was. It's nice to learn more about the different methods and their tradeoffs!
motoole2
@Tdog @elenagong The gaps between triangles are more for illustrative purposes here. It shows that a polygon soup does not keep track of the connectivity between triangles. Every triangle in this mesh has a set of vertices that is independent from every other triangle.
This is never actually used in practice, is it (by people who are familiar with the alternatives, at least)?
@jfondrie Even though it might be strictly worse than other representations in terms of storage cost, ability to access neighboring polygons efficiency, etc., it is still the simplest representation of geometry.
To test out the representations used in current 3D modeling software, I created and exported a mesh with Blender and looked at the RAW file values. Several of the exported file formats (e.g., .OBJ, .DAE) define the mesh in terms of an adjacency list which saves a bit on storage requirements. Surprisingly, even though the .PLY files can also represent geometry in terms of an adjacency list, the .PLY file that Blender outputs is a polygon soup, where any particular vertex is listed multiple times.
So clearly, this format is at least sometimes used in practice. :-)
Why are the triangles in the first rabbit gapped? Even with a polygon soup you should be able to store the vertex coordinates such that their edges are aligned.
I think the first rabbit shows how it is divided into pieces by the triangle cloud...?
I think it's really cool to be able to understand how meshes are encoded, because a few years ago I opened a 3d model file in sublime text and was blown away by how almost-readable it was. It's nice to learn more about the different methods and their tradeoffs!
@Tdog @elenagong The gaps between triangles are more for illustrative purposes here. It shows that a polygon soup does not keep track of the connectivity between triangles. Every triangle in this mesh has a set of vertices that is independent from every other triangle.