animating model interacting with another model

So I have this model of a character, and I would like to animate it drinking a glass of water. But I also have other animations on this model which do not require it to have a glass in its hand, if I child the glass to the model’s hand however it will be present in all other animations.

So how do I make sure that the glass is only present in that one action? I could split it up into two blend files one with the glass and another without but that seems like a lot of overhead for something so small. It would also be a pain in the ass working with this in Unity because I would need to change the models in code.

Can anyone help me with this?

So, you want a parent/child relationship that is sometimes active and sometimes not. To do this you add a Child Of constraint to the glass with the hand, or hand bone as the target. You keyframe the influence of the constraint to 1 when you want it active and 0 when you do not. Make sure you keyframe it to 1 for the whole of the animation sequence when you want the glass in the hand and on the next frame keyframe it back to 0. also keyframe 0 at the start of the animation (frame 1) and at the frame before the “glass” animation sections starts.

To enter a keyframe in the “Influence” box, simply go to the required frame in the Timeline, type in the value you require, then RMB-Click the box and select “Insert Single Keyframe” - you can do this for any text entry box.

Cheers, Clock.

(Abroad the MS Fram, somewhere off the coast of Iceland) :slight_smile:

Go to 48:50 in this movie. You need to make child of relations between two bones in two different armatures. Then change influence on bone constraint.

Thanks it works! So keyframing a constraint for those wondering you do by hovering over the constraint strength on the right panel and keying with “i”.