Sky rendering improved

In a previous article I talked about a simple trick I used to make the clouds more vivid. Recently I added some more effects to the sky, namely : shadows.

Since I forgot to add a gif for the cloud-transparency trick here is one.

 

Simple alpha interpolation based on camera zoom

Since I use Box2d for physics I experimented a bit with box2dlights. I had some trouble finding an exact way to render shadows in 2.5. So I decided I didn’t need actual shadow on my objects, but I’d rather have some kind of crepuscular rays. (Out of pure lazyness)

The kind of rays I enjoy

To avoid having shadows cast from my world object I created a second Box2d world containing only clouds. I currently have 4 different textures for clouds, so when a new cloud is generated, a spherical box2d object is added at the center. To add some randomness, I also add a small amount of smaller circle shapes in the cloud.

Simple alpha interpolation based on camera zoom

To add some realism and a change the mood of the scene at night, the color of the light is changed to a “blue-er” tone at night.

private void updateAmbientColor(double timeOfTheDay) {
    final float blueRatio = 1 + (float) Math.sin(timeOfTheDay * (Math.PI) + Math.PI);
    float minColor = 0f;
    float maxColor = .25f;
    ambientColor.b = (maxColor - minColor) * blueRatio + minColor;
}

 

Finally, don’t forget to use the same trick for the shadows : the closer we are, the more transparent !

Simple alpha interpolation based on camera zoom

Thank you for reading so far ! Here is  a video of an accelerated day/night cycle for you to judge the end result.