View Full Version : How do I distribute objects on a surface?

06 June 2008, 08:29 PM
I need to distribute a number of objects on a surface, but they cannot all appear at the same time.
I was thinking of using either PaintFx or instanced particles, but I have a few questions..

If I use PaintFx, I need to be able to change the geometry used by PaintFx to a custom model (my own object).
However I don't know how to change the geometry used by PaintFx (is it possible at all)??

If I go for the instanced particle solution, my problem is that I need the instances to be oriented according to the normals of the emitting object(s). How do I do that? Do I need scripting, and if yes, could somebody please help me? :-)

The reason why I want to use either PaintFx or instanced particles is that it is possible to control how they spread..

Thanx in advance,

07 July 2008, 10:19 PM
Hey, Peter

I think that Instancing is the way to go. I am doing the very same thing almost. I am trying to create a stylized forest with a particle system. I have built 23 tree's, emitted my particles from my ground surface. And then Instanced all 23 tree's as the instancer. I had to write a script so that the instance would randomly pick the tree's i setup for instance. If i didnt, they would all be the same tree. By default the tree's i emitted were oriented the same orientation as my normals. I will send u a render if u give me ur mail, I am new to the society, and don't know how to post pics in the forums,


07 July 2008, 12:42 AM
Hi Peter,

I agree with Tristan. What you need to do is create your models, and center them at origin. Then create your particle system, and instance your models. Create a custom per particle attribute called something like instIndex and give it a rand() expression. Then to orient your models to the normals, just set the aim to velocity under the instancer tab in your particleShape's attributes.
A tip for doing that is to orient your models pointing in the X axis and freezing their transforms.

Hope that was clear!


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07 July 2008, 12:42 AM
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