# Obj files
## Vertex data
- [x] geometric vertices (v)
- [x] texture vertices (vt)
- [x] vertex normals (vn)
- [x] parameter space vertices (vp) Free-form curve/surface attributes
## Curves and Surfaces
- [ ] rational or non-rational forms of curve or surface type: basis matrix, Bezier, B-spline, Cardinal, Taylor (cstype)
- [ ] degree (deg)
- [ ] basis matrix (bmat)
- [ ] step size (step)
## Elements
- [x] point (p)
- [x] line (l)
- [x] face (f)
## Curves and Surface Elements
- [ ] curve (curv)
- [ ] 2D curve (curv2)
- [ ] surface (surf)
## Free-form curve/surface body statements
- [ ] parameter values (parm)
- [ ] outer trimming loop (trim)
- [ ] inner trimming loop (hole)
- [ ] special curve (scrv)
- [ ] special point (sp)
- [ ] end statement (end)
## Connectivity between free-form surfaces
- [ ] connect (con)
## Grouping
- [x] group name (g)
- [x] smoothing group (s)
- [ ] merging group (mg)
- [x] object name (o)
## Display/render attributes
- [x] bevel interpolation (bevel)
- [x] color interpolation (c_interp)
- [x] dissolve interpolation (d_interp)
- [x] level of detail (lod)
- [x] material name (usemtl)
- [x] material library (mtllib)
- [x] shadow casting (shadow_obj)
- [x] ray tracing (trace_obj)
- [ ] curve approximation technique (ctech)
- [ ] surface approximation technique (stech)
# mtl files
- [ ] new material name (newmtl)
- [ ] ambient (Ka)
- [ ] diffuse (Kd)
- [ ] specular (Ks)
- [ ] non-transparency (d)
- [ ] transparency (Tr)
- [ ] transmission filter (Tf)
- [ ] shininess (Ns)
- [ ] illumination model (illum)
- [ ] ambient map (map_Ka)
- [ ] diffuse map (map_Kd)
- [ ] specular map (map_Ks)
- [ ] shininess map (map_Ns)
- [ ] non-transparency map (map_d)
- [ ] texture anti-aliasing (map_aat)
- [ ] displacement map (disp)
- [ ] decal map (decal)
- [ ] bump map (bump)
- [ ] reflection map (refl)