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bjparch
09-20-2007, 05:35 PM
I am using Shape Instance to create newspaper headlines flying away from the camera. I will have over 100 total headlines coming on in 20 seconds, starting slow then coming on more rapidly. How can I speed up the birth rate over time? Changing the Speed operator only changes their speed after the birth.

Bobo
09-20-2007, 05:49 PM
I am using Shape Instance to create newspaper headlines flying away from the camera. I will have over 100 total headlines coming on in 20 seconds, starting slow then coming on more rapidly. How can I speed up the birth rate over time? Changing the Speed operator only changes their speed after the birth.

The Birth Rate is animatable, just enable Auto Key and enter the particle birth rate you want at any given time. Then open TrackView and play with the function curve to fine-tune.

bjparch
09-20-2007, 07:57 PM
Thanks, that worked great. Another question, how can I get each particle to fade on instead of just appear? I would like a 5-10 frame fade on each particle birth. I don't know how to script but can it be done with a script?

Bobo
09-20-2007, 07:59 PM
Thanks, that worked great. Another question, how can I get each particle to fade on instead of just appear? I would like a 5-10 frame fade on each particle birth. I don't know how to script but can it be done with a script?

Define "Fade on".

Do you want the particle to scale from 0 to 100% size, or to change opacity from 0 to 100%, or something else?
Most things can be done with clever wiring of operators and events, for the rest there is scripting.

bjparch
09-20-2007, 08:03 PM
I want to change the opacity from 0% - 100% in 5-10 frames.

Bobo
09-20-2007, 09:55 PM
I want to change the opacity from 0% - 100% in 5-10 frames.

There are several ways to do this without using PFlow Tools Box #3 or Scripting.


Add a Send Out test to the initial event.
Drag a Material Dynamic operator to the view to create a new Event, wire the Send Out with it. Add a Standard Material with a Vertex Color map in its Opacity Map slot to the Mat.Dynamic operator.
Add a Mapping operator to the second event, set it to Sync by Event Duration, go to frame 10, enable Auto Key and change the values from 0.0 to 1.0.
Add an Age test with age of 7 +/- 3 to the second event.
Wire the Age test to another event where the final opaque material of the objects is defined in a Static or Dynamic material, without the Vertex Color map.

This setup will normalize the animation of the mapping operator to the time a particle will spend in the event (between 4 and 10 frames) and assign the corresponding mapping value to the color channel which will control the opacity.

I would prefer this method.


Another method:


For 5-10 frames, you can simply create a Multi/Sub Material with 10 copies of your material, each copy with a different Opacity - 10,20,30..80,90,100%.

Add a Send Out test and wire to a new event containing Material Dynamic with the above Multi-Sub. Enable Sub-Material Rotoscoping > Cycle, enter the FPS (default is 30) and set Sync By to "Event Duration".

Add an Age Test and set it to 7 +/-3, giving you ages between 4 and 10.

Wire this test to a new event where you can place a material static with the final material, best a copy of the 10th sub-material from the previous event.

Now particles will get born and move immediately to the second event where they will get an Event Duration based on the Age Test and the material will assign a new sub-material to each particle based on how long it will stay in the event. Once the Age is reached, the particle will move on to the third event.

You can add all the forces and other operators instanced to both the second and third event to get the right motion...

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As alternative, you can also use a Material Dynamic with a Standard material using a Particle Age Map to control the opacity, but you will have to specify life expectation for the particles using a Delete operator and work in normalized time instead of frames, which might not be that intuitive.

Also, you can synchronize bitmap sequences to particle age, so you could use a black>gray>white bitmap IFL sequence in the opacity map slot of a standard material and tell the bitmap to synch to the time of the particle.

bjparch
09-20-2007, 10:20 PM
WOW, thanks. The only problem I see with this is my particles are a group of standard planes. Each plane has a seperate texture on it. Would I have to make one Multi-Sub object texture with all the headlines I am using?

I am attaching the Max file for you to see exactly what I am looking to do.

entrancea
09-25-2007, 03:13 PM
Hope this helps.Check the Max File.

http://download.yousendit.com/FDFF8D5E698B218A (http://download.yousendit.com/FDFF8D5E698B218A)

Cheers.

entrancea
09-25-2007, 03:14 PM
What I changed was:-I ticked all the options in Shape Instance Parameter.

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