split POP problem

[daniel.phillis]

evening Houdniks,

i have an interesting problem with the split POP..

i am making an exploding Hallogen light with ALOT of sparks flying around...

i made the initial 'explosion' / burst with a small amount of particles, and then used the split POP

to generate nice trails with some random motion added to the newly born 'child' particles.

problem is:

in the inherit attributes option for the split POP i have used set initial velocity

set to 0 with some variance which gives me the look im after - nice trails with some random motion on them,

very similar to fireworks...

( i know...sounds wrong - but the director loves it ! )

anyhow ive realised when rendering with motion blur cranked, the newly born particles

have random directions to their blur...so the split is removing all velocity

and randomising it on the new particles...which is correct according to parameters ive set...

I guess I need a way to force the vel from the 'leaders' onto the

new particles...and i tried this in SOPS by writing out the leaders to disk with trails

in sthe similar vicinity to the other particles...

and using transfer attributes....but only with limited success..

Now i see maybe i should'e used the 'add to inherited velocity' option in the split POP,

but this now totally destroys the look i have acheived so far...

any ideas ?

shouldi just be achieving this same kind of look in a more correct POP methodology ?

cheers

Daniel Phillis

www.houdiniadventures.blogspot.com

nice shape and motion

Edited March 27, 2010 by daniel.phillis

[daniel.phillis]

quiet around here lately

Edited March 30, 2010 by daniel.phillis

[Mario Marengo]

quiet around here lately

Please don't take this the wrong way, but I'm guessing that it's "quiet" because, unless you post a simplified example showing the problem, you're then asking someone to sit down and recreate it from scratch based on your description, then try to help you figure out a solution, which might be asking a little much, no?

So... a sample file is probably a good idea

[meshsmooth]

When a trail particle is spawned if you can store the velocity of the parent particle in a parameter called something like parent_v. Then in sops make a vopsop that lets you mix the parent velocity and the actual velocity. This will enable you to control the motion blur without changing the animation.

Try it and let us know how that works!

[daniel.phillis]

rob - that worked a treat - such a simple solution - thanx again !!!

in summary

add clone of v in a vb attribute before the split pop,

the spit pop passes the v attribute down to the 'kids'

out in SOPS, use a VOP SOP to make v the value of vb

(vb = the desired velocity / Motion Blur look from the head of the particle trail)

in the VOP SOP you can also use a mix to interactively mix between the old v and the new v (vb)

and by outputting vb into N as well, you can use display normals inthe view port for a visual guid to vb / v

nice one !!