picking up stuff

how would i go about animating a hand on an arm in first person to walk over to a drink and pick it up?

I just made a simple (robotic?) arm rig.
Anyway, I hope you know how to use armatures. If not, you can probably find tutorials on blender3d.org or in the manual if you have one.

First:
http://www.nerdsofparadise.com/he1.jpg

  1. Make the object that you want to pick up… in this case the sphere. Then make an empty: this will be what the target armature that controls the arm/hand/whatever. In other words, it is what the arm actually follows.

  2. Select the Object Buttons (circled in green). Go to the constraints area, click add constraint and select Copy Location in the popup menu. Make the target the name of the object you want to grab (the sphere is called Mesh). Turn the influence down so the empty stays where it is.

  3. Click edit. This allows you to control the influence with an IPO curve.

  4. In the Ipo window, choose Constraint in the popup menu that is circled. This lets us control the constraint properties with curves.

  5. click on the inf (for influence) on the right of the windows (not circled … sorry). Then ctrl+LMB at 0,0: this is where the empty starts. Create another point at 1 on the y (makes the influence max out- the empty is at the center of the sphere) with the endframe in the x. This makes the empty go from where it is to the center of the sphere over the amount of frames that you want.

Another Pic:
http://www.nerdsofparadise.com/he2.jpg
6. Create the armature that controls you arm. At the end of the chain, add another bone (this will be used for IK calculation). Select this bone in Pose Mode (ctrl-tab).

  1. Go to the constraint settings, the same as before. Make a contraint, only this time choose IK Solver from the popup menu. Make the target the Empty and leave the influence at 1.

Another Pic:
http://www.nerdsofparadise.com/he3.jpg
8. This and step 9 are optional, they are just used to make the hand part point at the sphere. Anyway, make another bone for your hand, and make it the child of the nearest arm bone, not the IK bone. Select this bone in Pose-Mode (ctrl-tab).

  1. Go to the constraint settings again. Choose Track To from the Add Constraint menu (This makes the bone point at a certain object). Make the target the object you want to pick up (the sphere). Sometimes it takes a little fiddling with the “To” and “Up” buttons to get the bone to point in the right direction.

Now you can view the animation and the arm should reach for the object to get picked up.
This is the last frame of the depicted anim:
http://www.nerdsofparadise.com/he4.jpg

For first person, you have to re-position the camera.

Hope this helps :smiley:

“Hope this helps?” Well, duh! :smiley:

If you are doing animation of the sequence (vs. a real-time game), then by all means take full advantage of camera cuts. For example, if you shoot the character walking up to the foreground cup, then cut to an over-the-shoulder of the grab-and-drink, then those are two entirely separate camera setups and you can do anything you want.

With CG you can even shoot two perfectly-aligned pieces and stub them together anywhere: by definition, “it won’t show.”

Not too long ago I had the sobering experience of really carefully planning a machinery-move for one of my kiosk sequences, and I was really thinking that it (and I…) was very clever. Fortunately I did an animatic rendering just to see how it played. :-? It wound up on the floor; fortunately it was never actually rendered in any detail.

old trick was also to use two layers.
an copy of the object is all the time in characters hand, but it’s hidden on invisible layer… and then you do object switch, when you want it to grab the object :slight_smile:

.b

basse: Ah, that’s also an interesting trick, didn’t think of that one yet. I always used the Copy Loc / Copy Rot constraint with influence ipo trick.