Gbx Light Bloom
Using the GbxLightBloom Effect
GbxLightBloom is a special type of light that inherits from the Unreal Light class. Typically you'll just use these for sun effects, but they could be used on anything. Currently, only 1 bloom is supported in the view at a time, but that could change if there is a need.
To add a bloom, just go into the 'Actor Classes Browser' and select Actor->Light->GbxLightBloom.
In the editor window, right click and select 'Add GbxLightBloom Here'. NOTE: For sun effects, make sure you place the bloom in the skybox.
After the Actor has been placed, there are some properties you'll want to edit before the light bloom will work clearly.
The most important of these is the light bloom texture located in the 'Bloom' section of the properties dialog. The 'Bloom' section defines two properties, 'LightBloomTexture' and 'RayLength'.
'LightBloomTexture' defines the shape of the bloom (circular, etc). If you find that your light bloom shows up as a big square, it's probably because you haven't set this property. This texture is typically some sort of gradient with the same data written to all 4 color channels (RGBA).
The next parameter is 'RayLength'. This is the number of rays eminating form the light bloom and directly affects performance. Each ray, is another rendering pass (in other words, one more time the geometry has to be drawn).
To define the color of the light bloom, use the 'LightColor' section and modify the 'LightHue', 'LightBrightness' and 'LightSaturation' parameters to your satisfaction.
Finally, to modify the overall size of the light bloom, you can edit the 'DrawScale' parameter in the 'Display' section.