particle emission along Bezier curve

Does anyone know whether it is possible to use the particle engine to get particles to trace a bezier curve. It looks as if something along these lines might be possible using the PSYS_SRC_TARGET_KEY, PSYS_SRC_ANGLE_BEGIN,PSYS_SRC_ANGLE_END constraints with the right parameters but if anyone has done this or knows a better option ( or that it simply won't work!!) then I'd love to hear.


Beq

I think you would have to move the source itself along the curve, and have it emit particles that don't go very far.

There is some feature to make the particles go to a target when they die. Maybe you could rez an invisible object, and make it follow the curve, and have the particles follow the object.

I think you'd need to use a prim for each bezier handle. The handle prims would shoot particles at the appropriate speed/direction and target the next handle in line. The curve would be generated by the combined effects of the push exerted on the particle, and the pull towards the target.

Seifart Surface has done some in-depth mathematics using particle systems to display a specific 3rd degree polynomial, and mark the derivative zeros with prims of those polynomials. He may be able to help you out with this, since it sounds like it will be a similar concept in execution.

I was going to say the same. I saw Seifert's particle-curves at "The Future" sim. You have multiple prims with each one referencing the next as it's PSYS_SRC_TARGET_KEY. Then fire off the particles on a timer.

The "PSYS_SRC_ANGLE_BEGIN,PSYS_SRC_ANGLE_END" parameters refer to the 3d space that particles are emitted as described by the particle pattern:


From http://www.nandnerd.info/particlesystem.php

Thanks guys for some useful responses.
I will investigate the work that Seifart Surface has done.

I'll let you know how I get on.

Beq

Along the same lines (pun intended): does anyone know the settings to get particles to emit along a straight line? I don't mean moving particles along a line using targeting, I mean that the particles should all appear randomly placed along a straight line - I can get an arc easily enough but a straight line eludes me.

I think I stumbled across the pattern and start/end angle settings to do this one evening while experimenting but I (typically) forgot to save the settings for future reference and now I can't remember them.

Or maybe I'm just remembering the effect wrong, altho' I'm sure I've seen this done inworld? Any ideas?

I've managed to construct some fun curved paths using various combinations of the following settings:

TARGET (some other prim, not self)

SPEED_MIN & SPEED_MAX (set to the same non-zero values)
ANGLE PATTERN, ANGLE_BEGIN & ANGLE_END both set to zero

ACCEL (pushing against the direction of particle spray and not directly towards the target)

You have a beam/spray of particles that curves as it is diverted by ACCEL, and then it curves again as it is diverted towards the target.

Requires some tricky balancing to put the curves where you want, and you'll have to play with the PSYS_PART_MAX_AGE value a fair bit too. (Burst rate should be low, like 0.01 & count set to 1)

Happy Tinkering! =)