{"id":22,"date":"2010-08-26T09:14:12","date_gmt":"2010-08-26T08:14:12","guid":{"rendered":"http:\/\/www.joesfer.com\/?p=22"},"modified":"2015-05-15T20:20:26","modified_gmt":"2015-05-15T19:20:26","slug":"surface-weathering","status":"publish","type":"post","link":"http:\/\/www.joesfer.com\/?p=22","title":{"rendered":"Surface Weathering"},"content":{"rendered":"
\"weathered\"<\/a>

resulting textured object combining dirt and rust<\/p><\/div>\n

Here is a project I’ve been working on lately: a surface weathering simulation<\/strong> prototype.<\/p>\n

Surface weathering is usually a type of texture synthesis<\/a> which aims to simulate the degradation of an object due to external agents -weather-. The textures are therefore tailor-made for the specific object the simulation is run upon, depending on its topology. Despite the results are seldom good enough on their own (it’s an automatic process after all), they are a good start for some further hand-tuning.<\/p>\n

The simulation method I have implemented is based on the paper called Visual Simulation of Weathering By \u00ce\u00b3-ton Tracing<\/a> which follows a process consisting on tracing particles carrying stuff <\/em>against the model, and simulate their interaction with the surface. The actual weathering simulation depends on what the particles carry – in my case<\/strong> I was interested on simulating dirt and rust over a metallic surface, but different kinds of degrading processes can be parametrized with this method<\/strong>, depending on the settings.<\/p>\n

Conceptually the simulation slightly resembles the photon mapping<\/a> algorithm, but instead of carrying light, we’re carrying dirt, rust, humidity, and so on…<\/p>\n

The implementation goes as follows:<\/p>\n