I want to make an animation of a bunch of dice rolling around on a table, and I have a more or less specific path in mind I want them to take.
Now, if I use physics, they just jump all over the place. I’ve tried guiding them by adding invisible obstacles, even a whole tunnel. But for one thing, they occasionally ignore the tunnel and jump out anyway, or they lose momentum over time and just come to a stop somewhere along the tunnel.
If I use animation, I obviously have to move every die separately, which is tedious.
So what is the best way to do this? (And is there maybe some way to give an object momentum, so that its speed is towards a specific direction? To stop it from slowing down and instead make sure it jumps in the direction I want it to jump? If I animate it to move in a specific direction, it just moves in a straight line. I wonder if there would be a way to make it still do a nice physics curve instead of a straight line.)
You can add a force field to really pull them around. The falloff power (‘Power’) factor is really important, basically the closer to 0 the more of an effect it will have (if it’s really low they can actually start to orbit it) Basically you keyframe the force force moving around, and at some poinnt you want it’s effect to stop so you keyframe the strength to go to 0 and the dice settle. Here’s a mock up.
Thanks for the reply. Okay, I’m trying to understand how your file works…how exactly are the dice connected to the empty with the force field? They don’t seem to have the force field setting activated.
They’re not connected, the force field attracts the dice, and they are sucked toward the empty. At the end, the strength of the force field is keyframed to 0 so the dice just follow their rigid body simulation, bounce and then stop. It’s just one possible way to have control on something like dice while retaining the natural rigid body motion.
Oh, now I see. The dice really just need to be active objects. (For some reason it didn’t work for me the first time, so I thought you had to enable force field influence on them or something.)
Another question: I wanted the dice to first fall down from high up, and then start being influenced by the force field. So I put the force underneath them to wait for them to fall towards it. But for some reason this causes the dice to fall really slowly. Why is that?
Yeah you need to bake or run the sim to get the force field’s contribution to work.
Without running tests I can’t be 100% but I think I know. Basically once the dice have fallen in the air below the force field they are being affected by two forces, 1) gravity pulling down, and 2) the force field pulling it up (towards it) so it is in effect overpowering gravity. Your best bet would be to either keyframe the strength of the force field to 0 to start (probabaly best), or move it quite a ways away so that the falloff doesn’t affect it much (could be tricky)
No, the dice already slow down when they’re still above the force field. You’d think if anything they should fall faster, since both gravity and the field are pulling them down (see the dropbox file I posted).
The weird thing is, the strength of the force field was already at zero. When I set it to minus it works again. No idea what I did there.
Anyway, do you mean the bake option that’s under the render menu (I thought that was for textures?) or is there another one specifically for physics?