HELP: Inverse build modifier

There is an object on which I want to put the build modifier but inverse. Like the object is ‘un-building’ up (if there is such word) :smiley: that also from the middle of the scene. Like at 40th frame. But the build modifier shows no object in 0th frame and starts building at 40 and finishes up. I want - there will be the object from 0 to 40th and from 40th, it will un-build up and disappear.
I tried to alter the keyframes in dopesheet, but didnt work. help please.

You can use a particle system with the explode modifier to ‘unbuild’ something.
See the attached blend file. Frames 1-50 use the build modifier to create the cube, then from frames 100-150 there is a particle system that the explode modifier uses to take it apart again. The particle lifetime is just 1 frame so the face just disappears.


build.blend (181 KB)

Build would be so much more conveniently useful with a simple “percentage of object” value to keyframe.
But you can achieve pretty much any result by keyframing the existing values.

Here’s an example for a 80 frame “unbuild”:
Length: 80
At frame 1: Keyframe Start at -80
At frame 80: Keyframe Start at 80
(you probabably want to switch the animation curve to linear)

I’m never really able to wrap my poor head around the time-logistics, but it’s not that hard to trial-and-error a satisfactory result.
Save often!