source: GTP/trunk/App/Demos/Illum/Rain/Readme.txt @ 2222

This application demonstrates the integration of rain to an Ogre scene. Rain is animated through pixel shaders, and rendered with refraction from the background scene.
This demo needs Ogre Dagon (1.2.5) and an NVIDIA shader model 3.0 compliant graphics card (Geforce 6 or superior).
It runs fine under OpenGL, it currently DOES NOT run under DirectX. It will work after porting to Ogre eihort, which introduces vertex texture fetch support.


Usage :
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- Use mouse and arrow keys (or numpad arrow keys) to move the observer.
- Spacebar pauses the particles.
- + and - change the particles sizes
- Q and S change the particles speed
- W and shift+W introduce wind blowing on the particles
- O hides the fps overlay
- printScreen captures a screenshot to a file on disk.
- esc to quit the application


Run :
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Go to bin/debug or bin/release directory and launch the program 'rain'. You will most certainly need to  modify the 'resources.cfg' file in debug/release directory to reflect your Ogre installation.


Build :
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Run and build the solution (rain.sln)

If you wish to modify the application, the most important parameters are set in the file CommonRain.h.
There, you can modify the number of particles (there are BILLBOARD_POS_TEX_SIZE² particles in the system), the type of particles (comment/uncomment the #define STREAKS and #define SNOW directives), and witch on/off the interaction between particles and light sources).


Documentation :
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A 'doc' folder is included, containing Doxygen generated documentation of the application. It also includes a basic overview of the method.
The following link will give you access to some videos of the application :
http://www.msi.unilim.fr/~rousseau/rain.html


Contact :
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Pierre Rousseau, University of Limoges (rousseau@msi.unilim.fr)