Picking up and dropping an object animation in Carrara

pnewhookpnewhook Posts: 70
edited December 1969 in Carrara Discussion

Hey all,

I'm having a problem creating an animation where I'm picking up, moving and then dropping an object. I've created an industrial manipulator that has IK attached. What I want is an animation sequence where the robot moves over to a crate, grabs it, then moves the box somewhere else and drops it.

Animating the manipulator is not a problem, using the IK target and keyframes. But how do I move the box? I've tried attaching and releasing the box to the IK chain (so the box orientation is always correct to the arm), then forcing keyframes on the box position at various points. That works as I'm doing it, but when I animate it, the box just stays where it last was and does not follow the manipulator.

Is there a good method for this? I want the box to track the manipulator realistically - it can't move around which is why I tried adding it to the end of the IK chain.

Any suggestions would be appreciated.

Thanks!

Comments

  • bighbigh Posts: 7,127
    edited December 1969

    pnewhook said:
    Hey all,

    I'm having a problem creating an animation where I'm picking up, moving and then dropping an object. I've created an industrial manipulator that has IK attached. What I want is an animation sequence where the robot moves over to a crate, grabs it, then moves the box somewhere else and drops it.

    Animating the manipulator is not a problem, using the IK target and keyframes. But how do I move the box? I've tried attaching and releasing the box to the IK chain (so the box orientation is always correct to the arm), then forcing keyframes on the box position at various points. That works as I'm doing it, but when I animate it, the box just stays where it last was and does not follow the manipulator.

    Is there a good method for this? I want the box to track the manipulator realistically - it can't move around which is why I tried adding it to the end of the IK chain.

    Any suggestions would be appreciated.

    Thanks!

    fake it - move the box yourself - forget the ik - best way

  • th3Digitth3Digit Posts: 16,250
    edited December 1969

    if there is something ithat actually grasps like a claw you could try bullet physics.
    your box might need to be skewed a bit wider on top
    make the box use physics in motion instead of keyframe
    set bounce to zero, friction and mass to 100% on it and the keyframed objects it interacts with say the claw? and floor
    then click on the little wand icon in the left hand corner and run the simulation
    you can in scene, physics set accuracy, collission distance etc

  • DartanbeckDartanbeck Posts: 13,963
    edited December 1969

    The other thing that evilproducer so often makes point of:
    Most of the time, when you see these actions on screen - they are almost never the same shot - unless, of course, this event isn't the focus of the shot and is just happening in the background, for example. But if it's an intense animation, where the box that Jesse, our hero, just got locked inside of, just gets grabbed by a menacing conveyor arm, which will be dropping said box into a nasty grind'em up machine, they'd show the box on the ground - stop. They'd show the machine arm coming close - stop. Focus on box, arm moves into position (possibile and probable stop here), the claws clench the box with a horrible crunch - fade to new view where the arm lifts the box which again fades to the shot where the box, held by the claw is moving toward the nasty devise - then a close-up of the nasty device running. Then we see the arm reach the final destination and ultimately - somewhere in there, the box drops!

    Not sure if that's what you're going for - 'twas just an example. I knew these points long before knowing ep. But with him reminding me, and others about this... I find that I often make my shots much longer that they really need to be. For most of mine - I was already planning on stitching many, many shots together to create the suspenseful single scene - so it actually helps that I make them a bit too long - so I can pick and chose when and where to crop the clips and use the same one more than once - if needed.

    Just some more food for your thoughts.

  • tbwoqtbwoq Posts: 238
    edited December 1969

    There are a couple of ways to drop and pick items depending on what the objects are and animation. Target helpers would probably work best.

    -Parent and align a 'Target Helper Object' to the object or part(a hand for example).
    -In the objects modifier tab you want dropped and picked up(the box), add a 'Track' modifier.
    -Have that Track modifier(the box) track the Target Helper Object in the axis and roatation as needed.
    -To drop and pick up, enable and disable(check/uncheck) the track modifier in the timeline.

    Depending on what the objects are, you can also swap or copy keyframes in the time by using the Save/Load component icons in the objects motion tab.

  • PhilWPhilW Posts: 4,380
    edited July 2013

    The way that I have done this in the past is a bit like a magician's sleight of hand trick - have two objects! Say you have a hand picking up an apple. In the first part of the animation, have the apple sitting on a table. But have a second identical apple parented to the hand and turn off visibility. The hand comes in, the fingers grasp the apple. At the crucial frame, switch visibilty off for the apple on rhe table and on for the apple parented to the hand. The hand can now move away from the table and it looks like it has picked up the apple!

    You can extend this idea as often as you want, so you could have someone picking something up and then throwing it by having three objects, with only one visible at any time.

    Post edited by PhilW on
  • DartanbeckDartanbeck Posts: 13,963
    edited December 1969

    Yes.
    I demonstrate this "sleight of hand" method in This Video, where I actually use two, entire Rosie characters. One has the swords parented to her body (Chest), while the second has them parented to her hands. If she was to drop her swords later, I could use a third Rosie where the swords aren't parented to anything waiting at the appropriate spot - when the frames line up, one becomes visible as the other becomes - well, not visible! :)

  • evilproducerevilproducer Posts: 8,555
    edited December 1969

    I was going to suggest the visible/invisible object method myself! Keyframing the Target Helper and tracking idea is also a great idea.

  • pnewhookpnewhook Posts: 70
    edited December 1969

    Wow - thanks for all of the immediate and great suggestions! I never realized what a great community we have here!

    I thought of the visible and invisible method, but unfortunately due to the number of objects I want to pick up, this would get cumbersome.

    Just implemented the Target Helper Object and track method and got it working. That's exactly what I needed (with a couple of minor mods). Thanks!

    I'll post an animation of what I did when I'm finished for those that are interested.

  • pnewhookpnewhook Posts: 70
    edited August 2013

    Hey all. Here is the final animation showing what I was trying to do. Note that I was more interested in working out the pick and place technique than the materials, lighting and camera work. Once I got the technique down this took les than half an hour to setup.

    http://www.youtube.com/watch?v=uhDm5priGdw

    Robot is an ABB IRB 2600-12 manipulator with parts imported directly from STEP originals (from ABB website), and is kinematically accurate. Motions are entirely IK based by dragging the IK Target attached to the end effector - no joint by joint motion. Boxes are attached and moved entirely by using Target helpers - not independently positioned.

    Comments welcome! And thanks again everyone for the awesome suggestions!

    Post edited by pnewhook on
  • evilproducerevilproducer Posts: 8,555
    edited December 1969

    That looks great! Good job!

  • DartanbeckDartanbeck Posts: 13,963
    edited December 1969

    Yes - that's exactly what you needed alright... looks excellent!

  • pnewhookpnewhook Posts: 70
    edited December 1969

    Same sequence but this time the manipulator did not place the last box correctly. It then falls using the physics engine.

    http://www.youtube.com/watch?v=CjBe-U3PQuU

  • DartanbeckDartanbeck Posts: 13,963
    edited December 1969

    I love it!!!! :)
    Very well done!

  • evilproducerevilproducer Posts: 8,555
    edited December 1969

    I echo Dart. Really neat!

  • evilproducerevilproducer Posts: 8,555
    edited December 1969

    You should stick the robot in a warehouse that looks like the one at the end of Raiders of the Lost Ark. :lol:

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