Virtual scenes, macros and animations I’ve created using the freeware raytracer, POV-Ray. Many of my illustrations can be found on my Wikimedia Commons user page. More POV-Ray-generated scenes can be found on my GearHead RPG page.
A tutorial describing how to record precise (to many decimal places) 2D screen positions of 3D POV-Ray objects so that you can then import them into other image editing programs.
An updated version of "screen.inc" with better support for different camera types. Also features the capability to retrieve the precise two-dimensional screen coordinates of any three-dimensional point in space. (For instance, for overlaying 2D elements on top of a 3D image in another application.)
An include file that renders a grid and axes onto your scene with options to select its overall size and detail, as well as to choose to hide or show a particular plane.
A macro that creates objects in the shape of a grid of longitudinal, latitudinal and radial lines. The objects can be used within CSG operations (e.g. intersections and differences), or as an object pattern (e.g. a pigment). An advantage over other techniques is that the thickness of the grid “lines” remains constant.
A collection of objects and scenes (initially created for GearHead RPG) and intended for use in 2D, isometric video games. The special effects “add-on” is available from this page as well. The “GearHead Game Sprites” on my GearHead RPG page are newer and better developed, but also include lots of stuff created by other people.
A collection of fractal objects including the Menger Sponge, the Sierpinski Pyramid and the Sierpinski Tetrahedron. All three objects can be used in CSG operations.
A mockup of the camera and lighting angles used in the video games Fallout and Fallout 2. These games use an unusual form of trimetric projection that is tileable in six directions.
A demonstration showing how adjusting a photographic camera’s distance and focal length, while keeping the target object in frame, can introduce geometric distortions (called foreshortening) into the image. The top number is the camera angle. The bottom number is the camera distance.
A demonstration showing the effect of changing a camera’s aperture over time. The distance of the camera from the focal point (i.e. the center of the scene) is a constant 16 units. Each gray tile is 0.25 by 0.25 units. The top value is the aperture valure (AV). The bottom number is the f-stop.
Different representations of the Earth’s latitudes.
Fig. a. A naive approach to specifying a surface of latitude would be to cut through the Earth in a straight line to form a plane.
Fig. b. However, it would be more accurate to say that on a spherical Earth, a circle of latitude forms a cone pointing toward the Earth’s center.
Fig. c. But the Earth deviates from a perfect sphere, and instead roughly forms the shape of an ellipsoid (greatly exaggerated in this image), causing this cone to become truncated. This representation corresponds to "geodetic latitude".
Fig. d. Ellipsoidal coordinates are used in the calculation of the Earth’s gravitational field. Within the confines of the reference ellipsoid the gravitational field lines very nearly form a truncated hyperboloid.