die a silent death

# 1 15-02-2004 , 06:25 AM

Registered User
Join Date: Feb 2003

Location: Los Angeles

Posts: 695

Hey gang,

I've got a very simple particle system using instanced geometry that has gravity and collides with a plane and comes to a stop.

What I want to do next is have each geometry object fade out when it comes to a stop. I've thought of trying to use a collision event, or just to script when the velocityPP = 0, but the thing is when I change the transparancy value for one, they all fade out since each instance uses the same shader.

Can anyone think of how to do this?

Quote

# 2 15-02-2004 , 11:04 AM

Registered User
Join Date: Oct 2003

Location: Cage #42 of the Asylum

Posts: 396

Try either assigning a ramp to the radiusPP, and tweak it until you like it, or try assigning an expressions to the Y position, age or velocity, and create a vertical asymptotus in it. user added image

If you want (on that) more info, just ask user added image

Quote

# 3 15-02-2004 , 11:51 PM

Registered User
Join Date: Feb 2003

Location: Los Angeles

Posts: 695

I can't shrink it, I need to fade it out. Thank anyway.

Quote

# 4 16-02-2004 , 12:20 AM

The Maya Mountain
Join Date: Aug 2002

Location: Seattle, WA

Posts: 8,245

add an opacity per particle array and map it with a ramp to control it.

-Mike
The Maya Toolbelt

Quote

# 5 16-02-2004 , 12:26 AM

Registered User
Join Date: Feb 2003

Location: Los Angeles

Posts: 695

But Mike, that doesn't work for instanced geometry, does it? I tried that.

Quote

# 6 16-02-2004 , 12:44 AM

The Maya Mountain
Join Date: Aug 2002

Location: Seattle, WA

Posts: 8,245

must've missed that part. I don't use instanced geometry much, but I'd have to guess that you could key the transparancy of the shader it uses.

-Mike
The Maya Toolbelt

Quote

# 7 16-02-2004 , 12:45 AM

Registered User
Join Date: Sep 2002

Location: Minnesota, USA

Posts: 3,709

It should because you're not fading out the original instances persay, more the actual "newly spawned" particle object(s) and its' contained instances via the opacityPP.

Understand? If not let us know user added image

Basicly, when you make the collision event, you now have a totaly new/separate set of instanced geometry.
It may be all coming from the same instanced object, but the new instances are separate from the original ones.

So you are not affecting the original instances with the opacityPP, just the new one(s) created by the collision event.

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

Quote

# 8 16-02-2004 , 01:00 AM

Registered User
Join Date: Feb 2003

Location: Los Angeles

Posts: 695

When I try using opacityPP nothing happens, it doesn't fade like i want it. My ramp does from black to white so shouldn't it fade? Also, how do I link the fade to collision or velocity?

Here's my file in case you want to take a look.

Attached Files

collide_v01.ma (73.1 KB, 241 views)

Quote

# 9 09-03-2004 , 08:36 PM

Registered User
Join Date: Dec 2002

Posts: 8

You can't animate the opacityPP of an instanced obj, you are "instancing " a single object. A work around is to create several duplicates of your original obj, replace the texture on each of them with a copy of the original, and have each one progressively more transparent. You would then create an instance library with all of these - in order- and have your particle instances cycle through the animation. you could script them to start the cycle at a certain velocity, or create a collision event and have the orig particle die and emit this new animated instance. etc...

Hope this helpful.

Quote