reactor.....groups of objects?

[jbOS]

hi,

 

i have a scene with a model of a xmas present that has 2 parts. a lid, and the main box.

 

i am trying to drop this in from the sky so it bounces around a little, settles, and then the lid is blown off as as confetti explodes from the box.

 

i have got it working exactly as i want if the box is one mesh with the lid and box combined, however i want it as 2 parts. So how can i get the lid and box to fall together and bounce around and then seperate into 2 parts that reactor can control?

 

i tried grouping the 2 parts but then reactor doesn't allow you to change the mass properties etc so it obviously doesnt work with groups.

 

any help would be most appreciated as i'm totally stuck on this....

 

cheers,

 

jb

[Stephen Thomas]

You should look into using the fracture feature in reactor. Objects component parts will hold together until they hit another object with sufficient force to break them apart. I used it before to animate a mirror ball smashing into the ground.

 

[Claudio Branch]

There is no need to use grouping. I got this to work quite easily by splitting the simulation into two parts. The entire simulation is 300 frames. I created a gift box with a lid and placed another box inside.

 

The first half of the simulation is simply dropping these three items onto a plane and letting them settle. The second half of the simulation involves using the box inside the gift box to push the lid off.

 

In the Reactor dialogue window you can specify the start and end frame. I used 1-150 and 150-300. To get the lid to fly off, I changed the properties of the inner box to "Unyielding" and created a keyframe for it's elevation change. I also rotated the inner box so it would push the box over while the lid flung away.

 

Hide the inner box while rendering and it's a done deal...

[Claudio Branch]

Bonus tip...link your camera target to the lid and you get some nice built-in camera shake!