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Le MenuJournal: Personal drivel
Schedule: Places I go Projects: Things I do Pics: Stuff I see Forum: Words people say Links: Places to go Sitemap: Everything Contact info:awilson AT cc DOT gatech DOT eduCollege of Computing Georgia Institute of Technology Atlanta, GA 30332-0280  |
Weathering Assignment PageThe Processing source code for the weathering can be found here: mesh.pde. The STL file for the knot used is here: 2.stl. Make sure that the stl file is in the working directory for Processing, and the stl file will be loaded when the program starts. The final version of the program uses a spherical 200x200 1+bounce gamma-ton implementaion. Press 'p' to start the weathering. It will print a message indicating its progress through the gamma-ton spawning points and indicate how many gamma-tons missed the model entirely. On my 1 GHz powerbook, this takes about 20 minutes to run.This is the original model used for all the weathering. It was found at: http://www.cs.duke.edu/~edels/Tubes/.  This is the first attempt at the gamma-ton weathering. Gamma-tons were emitted from random points on the hemisphere 1000 points from the center of the model. 200 random points were picked, and 200 gamma-tons were shot at the model in a cone about 40 degrees wide. As described in the paper, each gamma-ton hit had a 50% probability of bouncing. For this version, patina was deposited at each bounce.  This is the same hemi-spherical weather viewed from the top. Notice that because the patina is deposited on each bounce, the out- and upward-facing areas get severely weathered.  Same, viewed from the bottom. There is almost no weathering on the bottom, as should be expected given that no faces reflect towards it.  Here is the same emission as above, but a full sphere is used instead of a hemisphere. As expected the intensity of same areas is halved and spread to the rest of the model.  This is the weathering effect cause by the gamma-tons being emitted from a place directly above the model. The same 200 points by 200 gamma-tons was used, but each gamma-ton was only randomized slightly in its x and z directions. This should reduce the artificialness of having all completely vertical gamma-tons.  The weathering effect is very heavy on the top...  And light on the bottom. You can see the "splash effects" from the reflected gamma-tons on the bottom of some areas.  This is the effect when you only have the gamma-tons deposit patina when the stop bouncing. It almost eliminates weathering on the outward facing areas, but areas that are "internal" (meaning that they are accessible from bouncing off another area) are weathered. This gives the classic copper patina weathering when objects are in the sun or elements. Wind, people, and other things are likely to smooth the patina off the outside, while leaving it on the inside.    More complex models coming... Last modified 1 December 2005 at 11:19 pm by Adam Wilson | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||