I thought this would be a simple animation action, but I need some advice on how to accomplish slicing a carrot with a knife. I originally modeled a carrot with parts parented to an empty. That empty is parented to a characters hand that moves into position to slice off a part of the carrot. The knife comes down, and sliced into the carrot mesh, and then I would like the part sliced off to become unparented. Uh, I can’t keep the sliced parts visual transformation. If I use a child of for a sliced part, then when animating the influence, it returns to the original parent inverse position instead of the new position where I want the sliced off part to rest. Any help appreciated. Attached blend file with action where the first slice needs to be detached. Then subsequent animation will slice off another piece. The character will wave the carrot around and then continue to slice the carrot. Any ideas?
Visual transform doesn’t work. Using 2.73a blender. 64 win.
Tim
http://www.pasteall.org/blend/35110
Make an armature instead, with separate bones for each section of the carrot. Make a bone for the hand/knife and animate that, moving the bone’s position to “cut” through the carrot, then move the position of each sliced off part of the carrot as they fall over, are pushed away by the knife. Move the remaining carrot bones as a “set” to “wave” the carrot around, by grabbing all the bones of the remainder, having selected them all, and moving/rotating/key framing them as one.
Cheers, Clock.
PS I will have a play with this tomorrow, to test my theory - but I am sure from previous experience that this will work out nice and it’s an easy, simple technique. You will of course need a “root” bone (pun intended) to keep the whole object in the same relative position, don’t move this bone however.
Couple of quick random thoughts…
You could use rigid bodies to do this. Takes time to set up and animate and run simulations/tweaking settings, that’s the down side. Oh and yeah, rigid bodies need to be of size to work well, you may have to scale your scene up to get them to work. On the plus side to this, you don’t have to animate the carrot slices, the sim does that for you. See attached file, took me 1/2 hour to create and get working. It’s only 3 slices, but it would have taken me 1/2 hour to roughly block in by hand and animate one slice of the carrot, then even more time spent polishing the animation.
As to the carrot being sliced and moved around as well, follow the advice in clockmender’s signature. KISS = Keep It Simple, Stupid. Use one mesh object for the whole carrot, when the whole carrot is ready to be cut, replace the carrot mesh object with shortened mesh carrot and several slices. A cut up version of the whole carrot, separated out as each part a mesh object. Now you can try the rigid body, or hand animate each mesh object. Hand animating a mesh object (carrot slice) is as easy as using a single bone to work with. Nothing really to gain but complexity to the scene by using an armature for the carrot, IMHO.
Depends upon the look you are after. I’ve been thinking a ‘realistic’ look. If you’re looking for ‘southpark’ or ‘minecraft’ style animation, then go with the separate mesh object idea. Quick, down and dirty, and done…
Randy
Attachments
rigid_carrot.blend (478 KB)
OM Gosh. Thanks so much. Combined the advice and my carrot is being sliced. The fall off pieces are now rigid and I can roll them around with the knife. Sometimes I think I just go brain dead trying to figure these things out sometimes. Again thank you. Here is a playblast of the carrot being sliced. http://youtu.be/FnMUdDPyHa4