### The brep object

Brep stands for boundary representation. You define a solid describing its boundary surface.

You use polygon to make the surface. Every object with a boundary surface is contained in a .brp file.

The .brp file is a text editor, but this can be very complex and boring to write. You can use other program like 3D Studio for creating a model, save it like a .dxf file and convert it with program dxf2rt. Remember : dxf2rt convert only object formed by polyline not from 3dface.

Look at his declaration in a .rt file :

{ object

name breptest;

...

model {

name mm1;

constr 1.2;

interp 0;

}

}

This includes a brep object with name "breptest". It looks for model in the file "mm1.brp". First it look in the current directory, then, if RT haven' t find it, the program will look in the common model directory.

A particular subset are the brep formed only from triangles. They have particular possibility not allowed for general brep ( for now ).

The attribute interp create a smooted brep object, but you need that all the faces of the object are triangles.