Houdini - Trails

The following images were created as I played around with trails in Houdini. 

The trails are curves that are advected through custom vector fields.   Some are basic vector fields using curl noise.   Others are controlled by a new HDA I made for manipulating vector fields with curves and mesh surfaces.

I created a few different super fast curve shaders based on this forum post and from this entagma video.  I also added to some of these shaders to get some custom results for random colours on curves, colour over length and for adding gradients across curves.