Recent additions include several paintings and drawings plus

1) A 34 minute film presentation about a demolished Victorian iron railway bridge near Elvet station, Durham City -- a CGI study in industrial archaeology. The video is on Youtube, at this link.

2) A model of ultrasonic non-destructive testing -- signals from rough facetted cracks. Verbatim copy of a report describing a mathematical model of ultrasonic NDT which I I developed while working in the electricity generating industry many years ago.

3) A review of the modelling of trees by computer, including fractal trees, L-systems, biology-based models of growth, and CGI applications such as SpeedTree, UE5 and Houdini.

4) A simple account of photogrammetry -- the process of determining 3D information from 2D photographs. It covers the principles of calculating object positions in a scene from overlapping photos. Also stitching images together into a parorama, and other aspects of computer vision..

5) Drawing in perspective: How simple objects appear when drawn accurately. This includes a section on how computer graphics software rotates an object, plus an account of non-linear perspective using the map projections. A supporting article describes spherical triangles,

John Coffey, Cheshire, England, May 2026