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FlightGear Newsletter April 2013: Difference between revisions
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== Development news == | == Development news == | ||
Note to all contributors: Please also copy your newsletter additions to the changelog for the upcoming release: [[Next Changelog]]. | Note to all contributors: Please also copy your newsletter additions to the changelog for the upcoming release: [[Next Changelog]]. | ||
=== Advanced Weather === | |||
Advanced Weather's cloud placement algorithms are currently receiving a major overhaul. In reality, many scattered cloud layers form rather complex patterns on the sky. One strategy is to simply take pictures of these and project them as 2d clouds layers into the scene, which looks fine from the ground, but fails from close-up. Advanced Weather has always preferred to model as 3d clouds whatever can be modelled in 3d. However, this means that the intricate patterns need to be created by a suitable algorithm. | |||
So far, the first generation of placement algorithms have utilized rather simple geometries like grid patterns and random clusters. While this is usually not a major issue from the ground, it is quite apparent from high altitude - here is an example of a cloud distribution based on multiple clusters: | |||
[[File:Clouddist old.jpg|300px|Old algorithm results from 80.000 ft]] | |||
Second generation placement algorithms are based on more intricate semi-random patterns. These distribute clouds just in a different way (i.e. the result does not require higher rendering performance) and the placement algorithms are not even significantly more expensive computationally (perhaps 10% - the advantage all comes from smarter design) - yet they work much better approximating real cloud distributions. | |||
Here are the results for the same weather situation from 'stick bundle' and 'domains' - two of the new placement methods: | |||
[[File:Clouddist new1.jpg|300px|New algorithm results from 80.000 ft]] | |||
[[File:Clouddist new2.jpg|300px|New algorithm results from the ground]] | |||
Cloud distributions appear much more natural and appealing, especially from high altitude. Work is in progress to replace 1st generation by 2nd generation algorithms in both the online and offline weather models of Advanced Weather. | |||
=== Random Buildings === | === Random Buildings === | ||