llCloud

From Second Life Wiki
Revision as of 15:08, 26 January 2007 by Cid Jacobs (talk | contribs)
Jump to navigation Jump to search

   Outdated templated used

Please change the template from 'LSLFunctionAll' to 'LSL_Function' (just replace 'LSLFunctionAll' with 'LSL_Function', do this after fixing any other erorr messages.

  Either 'func_desc' or 'return_type' & 'return_text' must be defined

(Please use 'return_text' & 'return_type' or 'func_desc' to summarize the functions actions.)

Summary

Function: float llCloud( vector v );

Returns a float

• vector v

returns the cloud density at the object position + v

Examples

Notes

How clouds work:

   * SL features a cellular automata-based weather system.
   * There are 16x16 square cloud "cells" per sim (which means each is 16x16m in size).
   * The cloud density data is sent from the server to the client once every time the agent connects to a simulator via logging in or teleporting into a simulator.
   * The client attempts to render clouds from the cloud algorithm results sent from the server, which is why different clients can see different cloud formations and de-synchronises cloud view from the server over time.
   * The Z value in the vector is irrelevant (clouds are always between about 180-200m absolute height).
   * It returns a value between 0.0 and 1.0, with 0.0 being no clouds, and 1.0 very dense clouds.
   * Values returned above 1.0 - 2.0 indicate rainfall, but the option for rain is not currently implemented so values are capped at 1.0.
   * Clouds and wind are related. 


The cloud seed/growth/disipation algorithm uses a solenoidal vector field, which is a vector field with zero-divergence: nabla dot v = 0

This condition is satisfied whenever v has a vector potential, because if v = nabla times A then nabla dot v = nabla dot (nabla times A) = 0.

Deep Notes

Search JIRA for related Issues

Signature

function float llCloud( vector v );