Sampling Rain and falling Pixels blog - ZeppelinStudio

Posted in Engine Programming | Feb 26, 2013 | by Phil­ipp Schä­fer

Lately I’ve mainly been working on some secret “engine-endgame/-story stuff” (bos­ses, effects). I don’t want to reveal any spoi­lers or bore you to death with company-founding stuff howe­ver, so here are some things I did which are worth tel­ling…

Wea­t­her
I star­ted to add a small wea­t­her sys­tem to the game, which allows us to make it rain or even start a thun­der­storm in our dark environ­ment. The rain­drops are rea­li­zed with our par­ti­cle sys­tem and to simu­late motion blur they are drawn as lines. The dar­k­ness is imple­men­ted as a con­stant which has effect on our back­ground shader and the fluid fore­ground. The light­ning makes use of the same shader con­stant and algo­rithm, only with oppo­site effect. It is cal­cu­la­ted using two phase shif­ted sinus func­tions and a tan­gent func­tion (for the hard cut).

The wea­t­her will have dif­fe­rent pro­per­ties in each level to enhance the fee­ling of a large and diverse world. It will also fea­ture func­tions to create the right mood during our story parts and boss fights.

Anti-Aliasing
We had some ugly visual effects that were cau­sed by mul­tisam­pling, so for a long time we deve­l­o­ped on com­ple­tely wit­hout it. I am happy to announce that the sam­pling is up and run­ning again, so you won’t need to miss it in the next Dev-Demo update.
I also stum­bled over some papers dea­ling full­screen anti alia­sing – if you’d like to see it imple­men­ted, just leave me a com­ment and I will raise its prio­rity.

Post scrip­tum
Because my blog post tur­ned out to be kind of short this time… let’s end it with some shader bugs I cap­tu­red while crea­ting the red light effect.