Expression help

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# 1 24-10-2003 , 07:57 PM

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Join Date: Feb 2003

Location: Los Angeles

Posts: 695

OK gang, this is what I'm trying to do...

I have a particle system of instanced geometry, and I want each instance to face the camera similar to what a sprite would do. However I can't use sprites because of the geometry instancing. I've tried writing an expression, but to no avail. (I'm still new tro writing expressions)

Can anyone help me and tell me what type of expression to write?

Thanks muchly,
-dann

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# 2 24-10-2003 , 08:34 PM

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Join Date: Sep 2002

Location: London, UK

Posts: 3,198

Hmm... tricky one...

Maybe instead of instancing you write expressions to duplicate the geometry for each particle which already had aim constraints to the camera. Just an idea...

Here's how I used this idea in the blood cell animation I did few months ago: https://forum.simplymaya.com/showthre...&threadid=6495

Kari
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Do a lot, Fail a lot and Learn a lot!

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# 3 25-10-2003 , 03:00 AM

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Location: Los Angeles

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Thanks for the idea, but I know there is a way to script what I'm looking for, I'll just have to keep looking.

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# 4 08-11-2003 , 03:57 AM

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Join Date: Sep 2002

Location: Minnesota, USA

Posts: 3,709

Have you had any luck yet?

Israel "Izzy" Long
Motion and Title Design for Broadcast-Film-DS
izzylong.com

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# 5 08-11-2003 , 04:38 AM

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Posts: 695

No, I gave up. Actually I figured out a hack around this. I placed the center point of the particle object at the same location as my camera and linked the particle to the camera. Now when the camera loves, the particle object follows it right? Well since the particles themselves emit int the world, they don't actually care where the particle node goes. Then I asssigned the Aim Direction to be Position and they aim themselves at the position of the particle node's center point.

Not the cleanest method, but it works.

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# 6 09-11-2003 , 07:15 AM

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Join Date: Sep 2002

Location: Minnesota, USA

Posts: 3,709

Cool

Sometimes a hack is the easiest way to pull off the shot.

Good goin!

Israel "Izzy" Long
Motion and Title Design for Broadcast-Film-DS
izzylong.com

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# 7 14-11-2003 , 12:36 AM

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Join Date: Feb 2003

Location: Los Angeles

Posts: 695

Ugh! I just realized the stupid simple solution. Just give the object being instanced an aim constriant, and aim it at the camera. After that, every instance in the particle system will aim at the camera.

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