Fade2D is an easy to use Delaunay triangulation library for C++:

- Fastest multithreaded Delaunay algorithm.
- 2D Delaunay with Polygon support and Constraint Edges
- 2.5D Delaunay for Surfaces and Digital Elevation Models
- Grid Mesher, Delaunay Mesh Generator
- Polygon Clipping, Boolean Operations on Polygons
- Cut and Fill for Earthwork Volume Computations
- Free student license. Eval- and Commercial licenses with support are available

## Fade2.5D – Extension for Delaunay triangulations in 2.5D

A 2.5D Delaunay triangulation is a 2D Delaunay triangulation where each point (x,y) has a certain height: 2.5D allows exactly one height value z per (x,y) coordinate pair and that distinguishes it from 3D. It works for surfaces which have an intersection-free projection to the x,y-plane like a terrain while closed objects such as e.g., a ball do not have such surfaces. Applications for Fade2.5D are surface metrology and terrain triangulation from LiDAR data. The Fade 2.5D extension comes with a buch of additional algorithms:

- Fast computation of ISO lines
- Height queries for arbitrary (x,y)-coordinates
- EfficientModel-class to reduce a point cloud within a user specified tolerance
- SegmentChecker to compute segment intersections. Works even in the practical case where two line segments intersect in (x,y) but at different heights (both heights are reported then)
- 2.5 Mesh optimization: Fade2.5D does not only lift a 2D triangulation but can optimize a triangulation for the local slope

## Constrained and Conforming Delaunay

Constraint edges can be inserted. This works also in 2.5D.

## Delaunay mesh generator

The mesh generator creates high quality triangles inside a given area. The quality of the triangular output mesh can be controlled by specification of a minimal interior angle that will be kept by all triangles (as far as existing constraint edges allow). Additionally a target value for the length of the edges can be specified which is often required for simulation purposes. The mesh generator is available in 2D and 2.5D.

## Performance of Fade2D

Fade2D is multithreaded and very fast. One million points take 0.16 seconds on a Corei7 6800K. Have a look at this comparison of single- and multithreaded runs with large point-sets.

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