Falling Leaves simulation

[sacslacker]

You could add a turbulence field to them. I guess it depends on how realistic you want things.

[baran]

U can add a random rotation for the planes. Also try with some conserve and turbulance. this will give a nice stay for a moment and then pickup the speed of the flow.

[Fess]

Hey sacslacker, baran

Thanks for the info, I'll give it a shot. :beer:


-Fess

[Ge-ZUS]

If you want the leaves to be able spin on every axis, try to write a runtime expression that contains a randomizing vector that changes very slowly

ie:

rotateX = rand(<<-1,-1,-1>>,<<1,1,1>>);
rotateY = rand(<<-1,-1,-1>>,<<1,1,1>>);
rotateZ = rand(<<-1,-1,-1>>,<<1,1,1>>);

actually, the problem with my expression is, that the vector would change waaaay too sudden (value and direction) :-(

but look at it as a hint ;-)

---> but i'm gonna have a look at it at home...bb

[plug3]

To get smooth rotation increment the rotation on each axis by a small random number:
rotX = rotX + randomNumber

And to get more realistic increase it depending on the velocity
rotX = rotX + (randomNumber*velocityFactor)

[5parts]

To get smooth rotation increment the rotation on each axis by a small random number:
rotX = rotX + randomNumber

And to get more realistic increase it depending on the velocity
rotX = rotX + (randomNumber*velocityFactor)

So whats velocityFactor? did i just miss it as an attribute you have to add, or is it a custom attribute which, at runtime, calculates the mag (partShape.velocity)? Or am i totally off here?

[plug3]

So whats velocityFactor? did i just miss it as an attribute you have to add, or is it a custom attribute which, at runtime, calculates the mag (partShape.velocity)? Or am i totally off here?

You're right it's an added attribute (float) I was just writting 'pseudo' code.

in mel the runtime expression is:
leafParticlesShape.velocityFactor = (mag(leafParticlesShape.velocity)/10);

In the project I did I only used this velocityFactor to increment the rotation (no random number) and got a nice rotation motion.

[Fess]

thougth this thread was dead...

To add rotation to the instanced particles here's what I did:
1. select the particles
2. attribute editor>particleShape>Instancer (Geometry Replacemet)>Rotations Options>Rotation
-set to "Velocity" will give a very fast rotation
-set to "WorldVelocity" will give a very natural relaxed rotation

playblast (http://www.mohan-conceptual.com/maya/leaves_final.mpg) (using WorldVelocity)



_d1

I'm curious about your runtime expression.
the "velocityFactor" is a added attribute from the particleShape1>Add Dynamic Attributes>General>Particle Tab?
I could not find that attribute.....

Any advice on this?
Thanks
-F

[Aikiman]

heres a good leaf tut..

http://www.learningmaya.com/t_leaves.php

[Fess]

Aikiman,


That was just the right tutorial. Thanks buddy :thumbsup:

-Fess

[plug3]

thougth this thread was dead...

To add rotation to the instanced particles here's what I did:
1. select the particles
2. attribute editor>particleShape>Instancer (Geometry Replacemet)>Rotations Options>Rotation
-set to "Velocity" will give a very fast rotation
-set to "WorldVelocity" will give a very natural relaxed rotation

playblast (http://www.mohan-conceptual.com/maya/leaves_final.mpg) (using WorldVelocity)



_d1

I'm curious about your runtime expression.
the "velocityFactor" is a added attribute from the particleShape1>Add Dynamic Attributes>General>Particle Tab?
I could not find that attribute.....

Any advice on this?
Thanks
-F

Yes it is an added attribute but you define it. Like in the tutorial Aikiman posted. Except it would be a float instead of vector.
The animation looks good. You should add a turbulence field, it does wonder and you don't need any scripting.

[HowardM]

You could also try softbodies if you want them to actually bend and curl :)
Check out this thread http://forums.cgsociety.org/showthread.php?t=350109

cheers

[Fess]

_d1Yeah I agree about the turb fields, just found the trick of using 2 turb fields with slightly different mag & phaseY settings will cause them to battle and produce some interesting effects.

Howard, great link buddy. I'll definately look into it.

Thanks
-Fess

[Fess]

Hey guys,

I was reading about particle looping. The instructions were to select your particles on the last frame of the sequence & choose Solvers>Initial State>Set for Selected. Now the first & last frames will match.

I tried it with my leaves but when I loop the animation, its not seamless. :banghead:
I also tried it was simple particles and its not seamless.

I did a search but the threads are the same as the instructions i read
http://forums.cgsociety.org/search.php?searchid=4866190

Can anyone do a simple demo or perhaps point a tutorial out cause it seems so simple but I'm not able to do it....fustrating.

Thanks
Fess

[Aikiman]

yeah Fess, I went to your link and tried Alexx recommendation as follows...

-create your particles.
-define the time you want them to cycle (e.g. 100 frames (pal 25fps))
-set the lifespan to "constant" and for the time set 100frames (=4 sec in this case)
-play the simulation to frame 100 and stop there.
-"set initial state" for the particle system

Im pretty sure that this is working for me, have a go

[Aikiman]

okay sorry, its not working for me.

[Fess]

okay sorry, its not working for me.

:)
I'll have some time tomorrow to play with it & problem solve this cause its annoying me.

[baran]

here is the simple scene with particle looping.

[Fess]

here is the simple scene with particle looping.

Thank you my friend...:beer:

I have looping particles now....

What I did:

-create a emitter.
-emit your particles.
-define the time you want them to cycle (e.g. Using (NTSC 30 fps) 120 frames equals 4 seconds of play). Go to Windows>Settings/Preferences>Settings
Time: NTSC (30 fps)

Go to Windows>Settings/Preferences>Timeline
Playback Start/End: 1.00 120.00 (remember this is 4 seconds of play)
Playback Speed: Play every frame

-go to Attribute Editor>particleShape1>Lifespan Attributes:
Lifespan Mode: Constant
Lifespan: 4 (4 seconds equals 120 frames @ NTSC 30 fps)

-play the simulation to frame 120 and stop there.
-select your particles, go to Solvers>Initial State>Set for Selected.

Fess

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