What about the .obj file?

Question

C++ / C#

I wrote my own 3d model parser, but did not take into account one thing, that all models are set differently, and the model that I tested was displayed normally, while those downloaded from the Internet were not displayed at all.
The question is, how can you set the connection between the vertices in a different way, if it reads only 3 connections
. For me, it reads only like this: f 338 339 340
In the file like this: f 343 342 344 337

Answer 1

f defines not a triangle, but a surface in triangle strip
mode f v1 v2 v3 v4 ... defines a surface of triangles v1 v2 v3, v2 v3
v4 ... ObjViewer