These statements say how the elements after them are drawn. Like grouping statements, each sets a state that lasts until another of the same kind changes it.
Materials and maps
| Statement | Meaning |
|---|---|
mtllib file1 [file2 …] | The material library files to read, searched in order. |
usemtl material_name | The material of the following elements. It can be changed, but not cleared. Elements before any usemtl are white. |
maplib file1 [file2 …] | Texture map library files, searched in order. |
usemap map_name or usemap off | The texture map of the following faces. The default is off, and it is ignored on faces with no texture vertices. |
A material statement names a material; it does not describe one. The description is
in the .mtl file, which is separate from the model.
Polygon display attributes
| Statement | Meaning |
|---|---|
bevel on|off | Bevel interpolation of polygon edges. Off by default. |
c_interp on|off | Colour interpolation. Off by default. |
d_interp on|off | Dissolve interpolation. Off by default. |
Level of detail and proxies
| Statement | Meaning |
|---|---|
lod level | Level of detail, from 0 to 100. 0, or no statement at all, shows everything. |
shadow_obj filename | Another model that casts this one’s shadows. Only the last one in a file is used. |
trace_obj filename | Another model used in reflections. Only the last one in a file is used. |
Curve and surface approximation
These apply to free-form curves and surfaces only. The surface’s settings, not a curve’s, control trimming and special curves.
| Statement | Meaning |
|---|---|
ctech cparm res | Constant parametric subdivision: each segment is split res × degree times. 0 gives one line per segment. |
ctech cspace maxlength | Constant spatial subdivision, with segments at most maxlength long. |
ctech curv maxdist maxangle | Curvature-based subdivision, limited by a distance and by the angle in degrees between tangents. |
stech cparma ures vres | Constant parametric subdivision in each direction. Both 0 gives two triangles a patch. |
stech cparmb uvres | A refined triangulation from one resolution value. |
stech cspace maxlength | Subdivision until edges are at most maxlength long. |
stech curv maxdist maxangle | Curvature-based subdivision, limited by a distance and by the angle in degrees between normals. |