Lights following splines

[tricky]

Any tips on how to animate lights (or glowing geometry) along splines to simulate car headlights?

I have a motorway and I want to have light streaks going up and down it as you would get with a timelapse video. I had a go by creating a spline and using Pflow to get a system flowing down the spline using squares aligned to the camera with a simple bitmap applied to the squares. The result is ‘ok’, but I am an absolute novice with pflow. With that simple system I have pretty much exhausted my knowledge!

This looks ok for one streak, but how would you randomly repeat that along either the same, or a different spline so there is a constant ‘pulse’ of car headlights zipping around?

Is pflow the best solution?

Opinions/tips appreciated.

And is vray capable of rendering something like this? Using scanline with a self illuminating material took about a second. On vray, it took about 20.

[hoppergrass]

have the spline be renderable and self illuminating, then animate a mask to run down the path. you could randomly offset the mask key frames to simulate many cars

[fixeighted]

Here is a script

Vehicle light trails script | Lucas Milner

There is another plugin I used called Ghost Trails http://www.ghosttrails.net/

[_Lele]

@tricky

And is vray capable of rendering something like this? Using scanline with a self illuminating material took about a second. On vray, it took about 20.

If you aren’t interested in those headlights lighting the environment around them, you could put their materials into a vrayMtlWrapper, and turn off GI generation.
That will speed the render up noticeably; possibly not as quick as scanline, but close enough provided they aren’t a million float in intensity.

[tricky]

Thanks guys. Useful ideas to explore…