Ray tracing

 

This picture created in 2005 is a synthetic (or "virtual") image I made on my Macintosh using Persistence Of Vision (POV) Ray-tracing. The image is built geometrically, using so-called "Constructive Spatial Geometry".

All the objects are created and assembled by geometrical programming using POV. A virtual camera and virtual light sources are then set, and the picture is created ("rendered") by "ray tracing". By moving the camera around, you can take any number of 3D pictures of the same scene (see the house project), including panoramic views. You can also make animated GIFs (see the moving train). Textures and patterns are programmed with POV. I am particularly proud of my "Orient Express" section.

The Mac fans will notice that the iMac G4 is a little simplified. The screen itself is a dump from my own Mac.

In this other picture, 4 items are imported in form of "Image Maps": these are the Tintin picture on the wall, the photo on the desk, the apple logo on the pencil holder and the "Happy New Year" text on the desk. The other items are all constructed geometrically.

I have borrowed some of the wooden textures from Dan Farmer and Paul Novak. These are supplied together with the (free of charge) ray tracing software of POV.

I created all the other objects: the column, the table, the paperweight, the pencil holder and the picture frames, and assembled them to this picture. It took me about three days (in 1999)...

On my MacBook Pro (2018) the desk picture is rendered in 9 seconds. On the previous MacBook (2011), it took 38 s, on my Macintosh G4 with biprocessor at 1 GHz (2002), it took 3 minutes 17 seconds in a 1024 x 768 pixel size. On my Mac 8500 (1998), it took one to two hours, and on my old Mac IIci (1993), rendering the same image could take as long as a full day... The desk image is a compressed jpeg of 1024 x 768 pixels. The plant and the tree are based on a file by Jean-Laurent Pradel (1998). There are 21 parameters to play with and change the style of the tree, its leaves and its branches. You may see six examples in this page with different settings. The result looks somewhat artificial, but the image renders quite fast, because the algorithm used to create it is very compact, which does not mean it is simple.

* Note: Some of the images are animated GIFs. They have been designed to loop only a few times (typically 3 to 8 times). However, this doesn't always work, and sometimes the image loops forever. Additionnally, you may have to re-load the page.

April 2021