You can easily create lens flares with any renderer as a post lighting effect. However, there is a lot to be said for using a lens flare rig, sight within the 3D viewport, giving you the flexibility of seeing the effect in real time.
how to create a lens flare RIG from image mapped planes
Here, Atomic Perception shows how you can create a lens flare rig in Houdini, using a line-based plane system. The idea is to place different sprites or image textures that will compose the lens flare rig along each plane.
The file names for the image maps are generated by Houdini VEX code and stored on the attributes for each plane. The material style sheet will link the actual attributes to texture file name fields passing them to Houdini’s Mantra shader. The result is a simple multi-stacked lens flare when you look down the length of the line.
The assets for the tutorial have been made available, and can be found on Odforce here: Create a Lens Flare from Image Mapped Planes in Houdini.