advanced particle goal help?

[Aikiman]

Sounds possible with the colorAtPoint command. No sure of you setup but if you connect the particles to a closestPointOnSurface node then you can control the particles easier but it only works on planar surfaces and a floating particle grid above it.

[johnjoe]

Sounds like a good starting point. Do you know if there's any examples of colorAtPoint scripts floating around the net?

Thanks for your advice Aikiman, really appreciate it. :beer:

Joe

[Aikiman]

Here you go I wrote this...


float $pos[] = particleShape1.position;
setAttr closestPointOnSurface1.inPosition $pos[0] $pos[1] $pos[2];
float $u = `getAttr closestPointOnSurface1.parameterU`;
float $v = `getAttr closestPointOnSurface1.parameterV`;
float $goal[] = `colorAtPoint -u $u -v $v ramp1`;
particleShape1.goalPP=$goal[0]*0.8;
particleShape1.goalU=$u;
particleShape1.goalV=$v;


Basic setup as follows. Create a nurbs plane and a closestPointOnSurface node.
Write this in the command line...
connectAttr nurbsPlane1.worldSpace closestPointOnSurface1.inputSurface;
Draw a grid of particles above the plane and make a goal between the two, set the weight to 1. Create a goal U and V per particle attr. Now all you do is input ramp1 onto your plane and keyframe it, copy and paste the code as runtime and push play!

[pollart]

hi Aikiman (http://forums.cgsociety.org/member.php?u=174420)
when i write on command line it is giving this error

// Error: The destination attribute 'closestPointOnSurface1.inputSurface' cannot be found.


am i missing any step?

i created a plain and typed on command line > connectAttr nurbsPlane1.worldSpace closestPointOnSurface1.inputSurface;

thanks in advance

[Aikiman]

You need to create a cPOS node first by typing this in the command line...

createNode closestPointOnSurface;

now connect your nurbsPlane to the cPOS node

[pollart]

thanks Aikiman (http://forums.cgsociety.org/member.php?u=174420)

i am a bit new to this particles but i am managed to do most of the work by taking help from you guys. thanks to you and every one who is here

well i am really confuse with these nodes in connection editor. where can i see all the nodes before i create them from mel? so that i can decide which one should i create.

i am interested to learn more of it. could you please suggest me the way how to learn about all the nodes? i dont mind to buy if there is any DVD out there? or online tutorials would be great.

any help would be appreciated

thanks dude

[Aikiman]

Well the only node I mainly use that you "cant" see before you use it is the closestPointOnSurface node. Some other nodes are loaded when you load certain plugins, but the only ones you really need to worry about already exist in the Render Nodes in hypershade. If you want to learn about those ones, Digital Tutors has a DVD out on them.

[pollart]

hi do you know the title of the DVD?

thanks

[Aikiman]

hi do you know the title of the DVD?

thanks

Mastering Maya Render Nodes (http://www.digitaltutors.com/store/product.php?productid=91&cat=41&page=2)

[cosku]

Hey Jeremy,
I didn't try applying what you describe yet, but from intuition, I feel like doing that will just turn on the goal-behavior for the parts the ramp goes to.

I think what johnjoe is asking is how to control goalU & goalV depending on where the animated ramp goes, which is tricky indeed.

[Aikiman]

Hey Jeremy,
I didn't try applying what you describe yet, but from intuition, I feel like doing that will just turn on the goal-behavior for the parts the ramp goes to.

I think what johnjoe is asking is how to control goalU & goalV depending on where the animated ramp goes, which is tricky indeed.

Yes, my method is pretty basic I admit. Im not sure if johnjoe has had any success yet.

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