View Full Version : Can a Collision Event trigger an Animation???

08-24-2006, 01:25 PM

I have a wall of little evenly spaced squares. I want the squares to rotate around their individual Y axis 180 degrees in a cool ripple effect. I don't want to animate each square's rotation individually and offset them by hand.

It would be awesome if I could move a sphere through the wall of squares, and when the sphere touches a square, it makes the square rotate. If I had a setup like this, I could have all sorts of shapes trigger the squares to spin in cool patterns across the frame. Any thoughts?

Can a collision event trigger a .mdd file? Could an object or collision event trigger an object replacement with the spinning square? Thanks for your thoughts!

08-24-2006, 01:34 PM
I am no expert with .mdd but seems like you could edit the .mdd to the keyframe where the ball hits the blocks.


08-24-2006, 01:39 PM
How many squares are there in the animation?

Some times just offseting using the dope track in the scene editor is quicker if you have say 100. Otherwise you will probably have to create a time based expression to control them.

Its an interesting challenge though and I may just have a go myself to see if I can find an effective method...

08-24-2006, 02:25 PM
Off the top of my head : Expressions with Relativity.

1) Use the distance to object function. You can then trigger the rotation of each plane when the distance between sphere and plane gets to be the radius of the sphere. Ideally, you want to look at the radius of the sphere (as modelled) multipled by the scale. Compare that to the distance from the origin of your plane object. Pythagoras will give you this easily enough. If the two match, trigger your rotation. Set it up for one plane and then copy/paste to other planes, or clone the original object. Easy; should take all of 10 minutes.

2) Relativity can also provide expression controlled morphs. That may also do what you want, perhaps also with the MDD node *shrug* Not tried this, but seems reasonable depending on how you are working.

08-26-2006, 06:27 PM
Thanks guys! If there's time on this project, I'll go for more interesting shapes to trigger the rotations. Meanwhile, I got by with animating all the squares rotating in a straight wave. Then I separated the rows in After Effects with masks. Now I can offset layers in After Effects to make different shapes. Thanks again for the tips. Certainly something to play with.