htrdr-obj(5)
NAME
htrdr-obj - file format of the ground geometry in htrdr(1)
DESCRIPTION
A htrdr-obj file is a regular OBJ [1] composed only of triangular meshes. Each triangle must be included in a material group as defined by the 'usemtl' directive. The name of the material group must be of the form "<front-mtl-name>:[<interface-mtl-name>:]<back-mtl-name>", where <front-mtl-name>, <interface-mtl-name> and <back-mtl-name> are strings separated by a colon (:) defining the name of the front, interface, and back facing materials, respectively. The interface material name is optionnal: it is used for thin geometries, i.e. geometries with no thickness. Material names can be composed of any characters expected for spaces and tabulations. Note that regarding the htrdr(1) convention, a triangle side is said "front facing" when its vertices are clock-wise ordered.
Note that to be a valid htrdr-obj(5) file for htrdr(1), the front and the back facing names must reference a material listed in htrdr-materials(5) file submitted to the htrdr(1) command line.
The grammar of a htrdr-obj file is thus a subset of the OBJ file format [1] with only a specific convention regarding the material name. As a consequence, any software supporting the OBJ file format can be used to create or visualise an htrdr-obj file.
EXAMPLES
Define a quad at the interface between the air medium and the concrete material.
-
v -5.0 -5.0 0 v -5.0 5.0 0 v 5.0 -5.0 0 v 5.0 5.0 0 usemtl air:concrete f 1 2 3 f 3 2 4
Define a wooden cube whose Z-aligned faces are against a brick material. The remaining faces are in contact with the air.
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v 0 0 0 v 1 0 0 v 0 1 0 v 1 1 0 v 0 0 1 v 1 0 1 v 0 1 1 v 1 1 1 usemtl wood:air f 1 3 2 f 2 3 4 f 1 5 3 f 3 5 7 f 5 6 7 f 7 6 8 f 4 8 2 f 2 8 6 usemtl wood:brick f 3 7 4 f 4 7 8 f 1 2 5 f 5 2 6
SEE ALSO
- 1.
- OBJ file format - <http://www.martinreddy.net/gfx/3d/OBJ.spec>
htrdr(1)