EMAIL: leibnitz@rcn.com NAME: Edward A. Leibnitz TOPIC: Journey COPYRIGHT: I SUBMIT TO THE STANDARD RAYTRACING COMPETITION COPYRIGHT. TITLE: SolarTransit COUNTRY: USA RENDERER USED: POV-Ray 3.5 TOOLS USED: Dave's Targa Animator, avi2mpg CREATION TIME: less than an hour for all the animation loops including ad-hoc re-programming of the utility. HARDWARE USED: Pentium 4 2 GHz 512 M RAM VIEWING RECOMMENDATIONS: I used RealOne Player - freeware version. Any MPEG player will probably work well. ANIMATION DESCRIPTION: The Topic is Journey: The act of traveling from one place to the other. Going from here to there, with meaning. Your chance to prove that it's not the destination that matters, but the journey itself. I hope this satifies: I realized recently that renders can benefit from shadows that reflect the actual position of the sun rather than guesswork (my original method). THIS ANIMATION IS NOT REALLY "ARTWORK": it is just a demonstration of a utility called SolarTransit.inc. This utility will place the sun "approximately" in the correct location given the date, the number of days in the year (i.e., leap year or not), time of day (standard am/pm, 24 Hour or elapsed minutes of the day) and the latitude. Southern hemisphere latitudes are represented as negative values. Optional information for more sophisticated calculations include: 1] Daylight savings time settings. 2] The location of a city in a time zone (a shift from -30 to 30 minutes to reflect the location of a city on a specific time zone). Sunrise is 4 minutes earlier per degree of longitude East of the imaginary time zone center line. User's note: This utility provides an approximation. It will be off (until further notice) by certain factors: 1] Issues related to the exact elliptical orbit of the earth around the sun as governed by Kepler's Law, or the heliocentric progression as governed by General Relativity. This is very difficult to calculate. It would require astronomical data that changes annually. Could be noticably different. 2] Factors not resolvable to within a given day such as the EXACT point of equinoxes and solstices. Most likely a negligible factor. 3] Factors related to infinite plane horizons versus real planetary curved horizons that have slightly different values for sunrises and sunsets. Most likely a negligible factor. 4] Factors related to the observed disc-size of the "true" sun ... i.e., in this setting it is rendered as a point-light and not an area light so sunrises and sunsets will be different. NOTE: A user can easily change this feature and implement a more sophisticated light source. Could be noticably different. User's may experiment with disc-shaped light-sources. 5] issues related to an exact longitude are being dis-missed for now. They can involve political issues related to what time zone you are in and whether or not daylight savings time is in effect globally. Additional note: Issues related to atmospheric-induced spectrum at a given time-of-day that are coded and/or rendered for display purposes are considered "test-studies" and DO NOT reflect any serious commitment on the part of the developer. These may change at any time. Second-party development is openly invited. DESCRIPTION OF HOW THIS ANIMATION WAS CREATED: The animation was performed with several animation loops with care to keep the endpoints continuous. 1] Place the statement #include "SolarTransit.inc" at the top of your code. 2] Place the statement TheSun in the appropriate location for your code. 3] goto SolarTransit.inc and set the features needed. 4] Over-ride the default sun point-light if desired. 5] Render. User's Note: This makes the positive x-axis to be due North. There are additional code sections in the utility used for this competition, such as potential animation loops and other #includes that can be removed if desired. It uses only POV-Ray. The resulting *.tga files were converted into an *.avi file using Dave's Targa Animator and the end-product mpg was created using avi2mpg. I am deeply disappointed with the quality of the final product in terms of compression artifacts. This looks nothing like the individual frames.