View Full Version : ParticleFX: Collisions

07 July 2003, 11:11 AM

Im having a problem with particle fx in LW7.5c and was wondering if anyone could cast any light on what I might be doing wrong:/
The setup is pretty simple. Im firing particles from an emitter against a sphere collision object. As these collide I need them to bounce off and create sparks from the collision.
In reading the manual, it sounds like all I need to do is create a seperate sparks emitter, parent it to the first firing emitter, and change the nozzle type to 'parent-collision', and hit start on the fx browser.

This isnt working for me however, and I get no spark particles as they collide :(. Any Ideas what I might be doing wrong?

If i change the collision object from bounce to erase, and change the nozzle type on the sparks to 'parent-end', they work, but obviously I dont get the extra bounce and the sparks erase too:/

Ive managed to find a couple of tutorials, but they're all of the 'erase' variety.

Thanks for any help.


07 July 2003, 11:32 AM
I'm not too sure about this as I've never attempted what you're doing but I think you need to set up groups for your emitters. Once the particle collides with the sphere, it should change groups to the bounce group. I hope this helps!

07 July 2003, 12:41 PM
Thanks for the reply oxygen_77.

Just tried that and yep creating a seperate group for the sparks stops them being erased by the erase collision object.
But...the only way I can trigger the sparks is by erasing the orignal parent particles at the moment, and if at all possible Id like to keep those AND create sparks:/
Thanks for the suggestion though:)

Does the 'parent-collision' work how i think it should, ie, if the particle hits a collision object, the child particles are spawned?

The easiest way to describe the effect im after is ricocheting bullets, creating sparks as they bounce around, and obivously if I have to erase them to create the sparks, I cant make them bounce:(


07 July 2003, 02:28 PM
Well, as I understand it the emitters are not random - so you should be able to clone the "bullets" to just make the sparks at impact. just an idea.

07 July 2003, 02:49 PM
Hi Cman.

If Im understanding what you mean, I could make a copy of the parent 'bullet' emitter, assign it a new group, let the original bounce, and the copy be erased to make the particles?
This is something I did think of, and should work, but for every bounce, youd need another copy of the emitter. The effect Im after is going to take place in an enclosed space, so theres gonna be a lot of bouncing and a lot of copies which is gonna make tweaking and editing a lot of work:(

Ive spent most of this morning trying to get this effect, which is something I assumed PFX did pretty easily. If you read the manual it sounds simple....

Create the emitters, parent one to the other, and set the childs nozzle type to 'parent-colide'. Create a colision object and press the start button. Easy.... I just cant get the bgger to work:)


07 July 2003, 03:52 PM
Basically u need to make second emitter (Sparks) child of the collision sphere, then u need to change nozzle type to Parent Collision and make generate by frame ...

Now make two groups - Sparks and say Bullets, make first emitter and Collision sphere - Bullets group and Sparks emitter Sparks group ... But it's not necessary think.

The last and important think is making ON
"Record CP" for collision object.

Obviously u need to play with various settings like motion , gravity , explosion ...

Here is the scene (Basikaly u need to make second emitter (Sparks) child of the collision sphere, then u need to change nozzle type to Parent Collision and make generate by frame ...) (pleas save target as)

Hope this help u :)

07 July 2003, 04:57 PM
the scene file at the bottom of this post may help you.

..but you want only sparks on collision not always right?

send us a scene so we can check it out.
its always tough with PFX or MD to describe what youre trying to do....

07 July 2003, 06:41 PM
Sorry for the delay in a reply, im back home now, but ill try that out at work tomorrow.

That break down sounds excellent Eugeny. I didnt think of parenting the sparks to the collision object:0 doh. I clicked on the record CP box, but with the wrong settings on the rest it didnt help me before. I tried more of the generate by sec, frame etc, but again, it didnt help. Ill sort the scene tomorrow and let you know how it goes. thanks a bunch:D

Howard, thanks for the scene:), ill tear that apart tomorrow, and learn what I can from it. One thing this has shown me is how little I know about a lot of the newer features in LW. Ive been on 5.6 since it came out, and only recently managed to persuade the management that the upgrades were worth it. Ive used PFX before but mainly for simple stuff, like rain, tornados, dust etc, but hadnt really done much with interaction.

Thanks for all the help


ps eugeny, check the link to your scene:D. I think I can guess what happened there LOL. thanks anyway.

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