OBJ
Object format for meshes
What is a .obj file ?
- A file containing informations about the geometry of 3D objects
- It can support colors and additional informations
- Can be modelled in Blender for example
- Defined by polygon faces (and so vertexes / points), normals, curves, texture maps and surfaces
- .obj is a vector size meaning there is no maximum file size
Useful links
Vertex data
A vertex is a point where the corners of a face / polygon meet. Vertex statements begin with the letter v and contain the spatial variables x, y, z, one optional variable w and variable values from 0-1
UV
Defines how a 3D odel is mapped onto a 2D surface such as a computer display and deterine how to apply textures to the 3D object. They are sometimes called "texture vertexes". UV statements starts with "vt".
Vertex normal
Can be constructed using the cross product between two edges in a particular direction. Defines shading and brightness by indicating the direction of a light source. Statements starts with "vn" and contains the space variables x, y, z.
Parameter space vertexes
Free form surface control points. Statements begin with "vp".
Surface data
Element data
Other elements that you can include are points (p), lines (l), faces (f), curves and 2d curves.