Use 1 object to affect an anim parameter of another?

I have an idea for an animation but am not sure how to go about it.

I’m going to have a large grid of cubes, let’s say 100x100 cubes. I’d like them all to scale up from 0% to 100%. However, I don’t want them to all scale at once. I’d like it to start at the center and then the scale would spead out.

Is there a way to do this. Is there a way to use the position of one shape to affect the scale parameter of another? Let’s say I scale up a sphere over time to fill the whole grid. Could I use the sphere so that if it touches an object, that object starts to scale, once the cube is completely covered by the sphere, it would be at 100% scale.

I know of the build modifier, which is what I will use if I can’t figure this one out. But I’d really like to use the scale of the cube.

Any help would be really appreciated.


I think this could be managed with either the Transform constraint or IPO Drivers (or even the Action constraint).

yes this is absolutly possible.
I would recommend the route via particles. Here is a mini tutorial on how to do it:
first insert a plane, then subdivide it so that the amount of verts matches the amount of cubes you later want to have.
Then add a cube (if you resize it, don’t forget to apply the size via ctrl a).
Add a particle system to the plane. Use the Cube as visualisation object. I’d recommend rendering the unborn, but if you are going from 0% size to 100% it doesnt matter i guess.

To the particle system:
Under Emit from, use Verts but don’t select random. Now do your math, and give the particlesystem the same amount of particles as the plane hast verts. (I tried to use the grid option there, but this oddly messes with my textural resize approach…don’t know why)
Now select the plane and UVmap it. Give the plane a nice texture…go for Blend type textures and there choose ‘Sphere’ or ‘halo’ … some people recommend painting your own, but these work fine.

Assign the texture to the plane -> press PAttr button in the map to tab.
And press time twice (so that its yellow/inverted). Check that “NoRGB” is selected and there you go.

but nothing happens yet.
With the plane selected go to the IPO editor. Select IPO type particle and add a new ipo.
Now CTRL-cklick to 0/0 and to somewhere else…for example x=60, y=1;
the second point defines how long it takes the cube to gain its size, once its activated (60 frames in my exapmple) and what size it should have at the end.(size 1 = 100% in my exaple).

now bake the particle simulation and there you go. :slight_smile:
i hope i have not forgotten any important steps…
If you like, i can post a blend file.