Source reconstruction of a mock lens. Top-left: Lensed image. Top-middle: Model reconstruction with the white points showing the source modeling points. These white dots are the points that are mapped onto the source plane to form the Delaunay triangulation vertices as described in Sect. 2.7. Top-right: Residuals after the model reconstruction is subtracted from the image. Bottom left: True source that is used in creating the mock data image. Bottom-right: Source model reconstruction with the white lines showing the Delaunay triangulation. The vertices of the triangulation are the positions after the points in the top-middle subplot are mapped onto the source plane using the lens model.