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Emmanuel
11-24-2009, 09:47 AM
Hi,

I am trying to achieve the ffect you see sometimes on photos that were taken at night where the lights of cars draw a really surreal pattern because the exposure time was chosen so that those lights leave a trail in the night.
How do I achieve this in LW ? I am trying to have a puck fly by the camera and have this really long, winded trail behind him....thanks for any tip !

Lightwolf
11-24-2009, 09:51 AM
As a start... use photoreal motion blur and crank up the percentage way above 100% (100% is the duration of one frame).

Cheers,
Mike

Dexter2999
11-24-2009, 10:11 AM
Or if you have a program like After Effects you can do it and play with how long you want the motion trails without having to re-render the scene over and over.

cagey5
11-24-2009, 10:22 AM
Or you could use a particle emitter to leave a trail in it's wake similar to the attached.

dwburman
11-25-2009, 12:00 AM
You could use an object with the inertia deformer as mentioned in this thread:
http://forums.cgsociety.org/showthread.php?s=&threadid=53040

You can also make something trail in LW by setting the background or foreground image (compositing panel) to the output render sequence. You'll have to save at least one frame (or just an empty image with the correct file name) so you can select it in the image editor. You'll have to set the image to 'sequence' and set the Last Frame & Last fields to the length of your scene/shot. This probably won't work for your project, but it can be used for light streaks or other effects.

archijam
11-25-2009, 06:28 AM
Or you could use a particle emitter to leave a trail in it's wake similar to the attached.

I like that. Any tips?

Nangleator
11-25-2009, 06:59 AM
No gravity, no inherit parent motion, little or no jitter, long enough life span, very high resistance. Surface with normal surfacing or HV.

cagey5
11-25-2009, 08:17 AM
I like that. Any tips?

Let me see if I can find the original scene. I'll post it if I can.

DonJMyers
11-25-2009, 08:58 AM
Setting motion blur to 1000% or more as suggested is what I would do. But don't for get setting motion blur to -1000% and you get trails going the other way - motion blur for objects which haven't arrived yet.

tribbles
11-25-2009, 10:49 AM
I did a laser light effect in LW using motion blur. I documented it here:

http://www.tribbeck.com/lightwave/laser/

http://www.tribbeck.com/lightwave/laser/lissajous_50_20c.png

It uses a moving bright object to create trails - they don't turn corners or things like that, but I think it can do the basis of what you want.

cagey5
11-25-2009, 02:00 PM
Let me see if I can find the original scene. I'll post it if I can.

Not sure it's exactly the scene from above but hopefully similar.
I've also included a short avi to show it in action. note. IT IS NOT A ZIP FILE. CHANGE THE SUFFIX TO AVI TO PLAY IT.