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Celshader
03-31-2003, 05:08 AM
An adaption of Adrian van der Park's "Trails of Light" technique; a.k.a. "Fun with Inertia." ;)
http://www.celshader.com/gallery/tests/trail02.mov

Capt Lightwave
03-31-2003, 06:53 AM
Cool. Could you post either some sort of tutorial of how you did it or at least the "van der Park" way of doing it?

Epita
04-01-2003, 12:58 PM
hey, thats really cool. could u show us how to do that, Also Akira is such a great film, but Metropolis might be better, (cmon it uses LW)

Epita

BarkingTreefrog
04-01-2003, 08:09 PM
Celshader, you rock! I would love to see how you did that as well. I am working on an animation that this technique would be perfect for. Any info would be great, and I would love you forever. :D

Mr_Q
04-01-2003, 08:14 PM
Yah, there was a short lived plugin that came out for LW 5.6 a couple years back that did that. But it died. I would love to know how you got that specific look.

I have a way to do it, but its not perfect.

Celshader
04-01-2003, 11:21 PM
Originally posted by Mr_Q
I would love to know how you got that specific look.

This animation came out of a discussion on the CGTalk board:
http://www.cgtalk.com/showthread.php?s=&threadid=53040

Someone wanted to know how to do Akira-style light trails in LightWave. Here's the posts I made in response to his question:

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Originally posted by Celshader
Adrian van der Park developed an excellent technique for this effect back in 1998, using geometry for the light trails and Lazy Points (now known as the "Inertia" plug-in in the Deformations tab in the Object Properties panel) to make the geometry stretch along the path of the object's motion.

I'll see if I can whip up a quick and dirty test...


Originally posted by Celshader
For what it's worth:

http://www.celshader.com/gallery/tests/light-trail.gif

You can see a bigger version here:
http://www.celshader.com/gallery/tests/trail02.mov

This is not the "guitar pick" object that Adrian van der Park used for his Trails of Light tutorial back in 1999, but it still uses his idea of applying LazyPoints/Inertia to geometry for a "light trail" effect. I took advantage of the modern LightWave's weight maps for this effect.

Trivia:
On each object, I used the same weight map to both surface the object and to control its animation in Inertia.
I used Glow on both light trails.
Each light trail is a box with a slightly tapered end, so that the trailing end appears reduced in size. Each light trail box has 100 segments along its Z axis, and has been tripled to reduce the chances of distortion.
These surfaces are not transparent. They have Additive Transparency cranked up to 100% instead.
Each light trail's surface has a Constant Value of 128 for its Alpha Channel. That way, the glow of objects behind the "light trail" can still be seen through the "light trail."
I put an envelope on Inertia's lag so that it has no lag at the beginning of the animation and its full lag rate by frame 12 -- that way its trailing end stays "soft" even at the beginning of the animation.


I hope this helps! :)


Originally posted by Celshader
...I used Align to Path for this animation. The box must be aligned along the Z axis in Modeler for this to work.

...

I started with a box that had 100 segments along the Z axis. I then created a new weight map with a value of 0, so that I had a "blank canvas" on which to paint my weights.

The secret to a gradient falloff of weights is the "Linear" option in the Weights tool's numeric panel. After activating the "Linear" option in the numeric panel, I used the right mouse button to click and drag out a falloff triangle (just like the falloff triangle for the Taper tool). When the falloff triangle looked the way I wanted it to look, I went back to the numeric panel and set "Change" to 100% and clicked on "Apply" to apply the weights. If the weights looked wrong, I typed u to Undo the Weights tool, adjusted the falloff triangle and tried again.

...

Capt Lightwave
04-02-2003, 12:38 AM
Thanks a lot, Jen !

Great use of the technique.

Epita
04-02-2003, 01:25 AM
well, that was helpfull... i dont know im ever going to use that, but its allways nice to see that everyone will share things with ppl here!yay

Epita

NeilNafus
04-04-2003, 08:30 AM
thanks for posting that, pretty usefull, simple and fast.

If you have more rendertime to spare you can also achieve a nice effect using particles.

http://www.nafii.com/neil/avi/Fire_Strings_Post.avi

This also has some soft glow added in post to it.

-Neil Nafus
http://www.nafii.com/neil

Neural Riptide
04-04-2003, 10:19 AM
I feel really lame asking this, but I've got the flow of the object working really well, but the pivot point of the object isn't staying where it should (curved red arrow on image)

I have Align to path on, and my inertia settings are visible.

Is this the way it's supposed to be?

evenflcw
04-04-2003, 08:10 PM
Wow, Celshader and Neil those look great!

Neil did you use lots of particles for that or did you use som trick to get such a nice long tail. I'd really like to see a tutorial on that one if possible. It looks soooo sweet!

NeilNafus
04-05-2003, 07:33 AM
The effect is pretty easy, I will make a more in depth tutorial soon but for the meantime I'll give a base explanation of it.

That particular scene I created an emitter with 25 or so particles, emitted on one frame and thats all that is emitted. Then I parented another emitter to it, now for the amount of particles emitted on this one you just kinda have to play with it along with your HV settings to make sure the string is solid. I set a wind to blow the first set of particles around and then made sure the others were not affected.

I'll work up a tutorial soon, however if you have any questions feel free to ask. I'll post a link to the tutorial as soon as I have it done.

-Neil

novadesigns
04-06-2003, 02:30 PM
Hey Jon, try turning off the Interia Pivot Object option, that fixed it for me :)

Meaty
04-06-2003, 10:11 PM
i have been wondering how to do this for the longest time, thanks!

toby
09-05-2005, 04:20 PM
Neil, that is so f***ing beautiful, please don't forget to do that tutorial! I don't think I could figure it out even knowing the basics you've supplied ;D

Julez4001
09-30-2008, 11:24 AM
Too bad none of this works on volumetric lights....

erikals
02-12-2019, 04:24 PM
a bump + a Self Reminder


https://youtu.be/8Ibb037pGd0

https://i.imgur.com/ycgfVzI.png