Marching triangles is a method for producing a polygon mesh surface approximation composed of triangular facets which are approximately equilateral. This paper presents an algorithm for improved triangulation when the inputs are range images of architectural scenes containing perpendicular edges. In particular, we detect fold edges (C^1 discontinuities) and use these to constrain the final triangulation. This increases the accuracy of the mesh at sharp corners and decreases the number of triangles with a poor aspect ratio.
