Newbie advice on collision tags

[Jim Scott]

Hi Matthew,

When animating in C4D you can choose to use either keyframing to move an object, or dynamics, but not both at the same time. Once you add a rigid body tag to an object its movement can no longer be keyframed (it’s now “rigid,” if that helps), which is what you discovered. Notice that in the parameters of a rigid body tag its “Dynamic” setting is “On,” meaning it only responds to dynamics (physics – gravity, friction, bounce). Because of this, you can’t move your objects to new positions through keyframing AND have them bounce off of each other through dynamics. It’s either one or the other. You can keyframe the movement of objects with collider body tags because their dynamics is off, but any pieces that you want to bounce off of them must have rigid body tags (dynamics on) and therefore can not be moved through keyframing. It is possible to keyframe the “Dynamic” setting of a tag from Off to On (in order to change it from a collider object able to push rigid objects, to a rigid object able to be pushed by collider objects) but if it’s touching any other dynamic object when you do so they will explode apart.

Unless someone else knows some magic to get around this issue I’m afraid that you’re stuck with keyframing the tangram pieces from one position to another in order to form new shapes while being careful not to allow any pieces to intersect. It’s an interesting project, and if I come up with some other approach I will let you know.

Hope this helps.

[Jim Scott]

I should have made it clear in my last reply that I was specifically responding to your desire to use keyframe animation with dynamics, but I failed to do that, so I just wanted to add that there are many other ways to animate in C4D, including effectors, fields and forces. I hope that I didn’t confuse you too much by implying that keyframing and dynamics are the only ways to animate, and that my discussion of dynamics and keyframing was helpful.