Rendering Light trails?

[Randolph]

Maybe an animated NURBS circle extrude along a curve (partial curve length) could be worth testing.

[lightcache]

if you have after effects ide throughly recommend trapcodes' 3D stroke

http://www.trapcode.com/movies/organic.mov



we used this some time ago for the effect you're after and it worked a treat.

[chuckie7413]

It would take ages to render this effect using maya and particles and motion blur. I would also definately recommend using Trapcode plugin for after effects to get this effect.

http://www.videocopilot.net/tutorials.html?id=42

great tutorials for everything after effects.

[qrichardson]

Though if you did a simple particle stream you could get a nice effect of the trails slightly drifting and I'm betting you could create the effect without using too much motion blure (so as not to crank up the render time)
I've been thinking of creating a similar effect lately.

Good luck

[altruizine]

I once brute forced it - trapcode wasn't panning out the way we wanted it to. We were flying thru the city and wanted the light trails - which means proper occlusion from behind buildings and other objects in the scene.

So, what we did was animate little spheres w/ full white or full red incandescence running on the car light paths w/ the timing we needed, then rendered those out using the hardware buffer at like 600 frames per second (I think we just did a *=200 on all of the keyframes in the scene) then used time echo & remap in aftereffects to get the streak look. It's a bit more work but you can get really nice results and proper occlusion if you camera is in motion...


jf

[Bitter]

The hardware render seems an interesting solution. I am aware of a plug-in for Lightwave that does that. But for Maya, neither mental ray nor Renderman can achieve that effect. It is generally done in post only. There are a few previous posts asking the same thing, and attempts to use motion blur fail in the render.

[i-d]

I must add this, in Houdini such an effect is about five minutes work

(including rendering), long exposure is all that it takes.
It is constant source of bevilderment how such trivial tasks
can be almost impossible to do in maya.

[jude3d]

you can do this effect in 3d with renderman and a custom accumulation shader on a path and opacity. it's not as easy as in compositing to do so create it in compositing this is the best solution to me.

[Bombata]

Thanks for all the suggestions guys, I was hoping to get something going straight out of Maya but after reading all yr comments I may have to rethink.

I agree particles with motion blur may be a expensive way to go...

[berniebernie]

render a matted sequence of the light (illuminated object/light on black background), making sure you render subframes or use mblur, then import all these images to layers in a photoshop file using the screen blending mode


okay, lots of work for a still image, I agree that we need a mi_long_exposure lense or something

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