How to pick up and drop an object in Blender
Oct 23rd, 2009 by admin
As I’ve answered this question a number of times on the forums recently, I’m going to put up a definitive post here. Hopefully anyone who searches for something like “how to pick up and put down an object in Blender” will find this and save everyone the trouble of asking again.
It’s a common situation in animation — a character needs to pick something up, carry it around, then sit is down. There are a number of ways to do it, but here’s the most reliable way I’ve come across. There are a lot of steps, each one critical. Follow this recipe and you’ll be able to do it:
Setup
1. Place your object in its starting position.
2. Add a Child Of constraint to the object, targeting the main hand bone of your character.
3. Your object will “jump” when you attach it to the hand with this constraint, so press the Set Offset button on the constraint panel to fix it.
4. Set a LocRot key on the object. This fixes its starting position.
5. On the Constraint panel, set the Influence slider to 0.0 and press the Key button to record it.
The Grab
1. Animate the hand into place around the object
2. Back up one frame
3. On the Object’s Constraint panel, press the Key button to once again record an Influence 0.0 keyframe.
4. Advance one frame
5. Change the Influence slider to 1.0, and set another Key for it
6. The object jumps out of position. First press Clear Offset then Set Offset on the Constraint panel to fix it
7. The hand now has full control of the object. Animate the hand/body/etc. to do whatever you like.
If a pick up is all that is in your shot, you’re done. However, if you need to sit the object down…
The Drop
1. Animate the hand so that the object appears in it’s resting position, i.e. on the desk, shelf, etc.
2. Back up one frame
3. Set another Key for the Constraint Influence at 1.0
4. Set a LocRot key on the object
5. Advance one frame
6. Set a VisualLocRot key on the object
7. Move the Constraint Influence slider to 0.0 and set a Key
At this point, the display screws up. It shows the object moving back to its initial position. This is an animation display bug. Advance and Reverse the frame counter once and you’ll see that it is where it is supposed to be.
The hand and object are now free to move about independently. Congratulations — you can now do something in 3D in nineteens steps that even a one year old can do in real life!
Wow… I wish I’d seen something like this a month ago. I struggled with this for quite a while before figuring out the right recipe. And the bug threw me for a loop for a while, too, thinking that it wasn’t working properly.
Thanks for putting it up somewhere where Google can find it so others can benefit.
This is an excellent tip sir! I actually just used it to solve a problem with an animation that I have been struggling with for days!
Thank you, this is an awesome tip, help me a lot…!!!