提示
As with all physics-enabled objects, pay close attention to the Animated checkbox in the Rigid Body panel of the Physics tab in the Properties. A common mistake is to use keyframe animation on a Passive physics object without checking the Animated box. The object will move, but the physics engine will behave as if the Passive is still in its starting place, leading to disappointment.
动画
The most common trick is to Keyframe animate the location or rotation of an Active physics object as well as the Animated checkbox. When the curve on the Animated property switches to disabled, the physics engine takes over using the object’s last known location, rotation and velocities.
设置各种其他参数的强度动画 ( 机动的 目标速度, 铰链的 限制等。) 可用于完成各种有趣的结果。
Enabling a constraint during the physics simulation often has dramatic results as the physics engine tries to bring into alignment two objects which are often dramatically out of alignment. It is very common for the affected objects to build up enough kinetic energy to bounce themselves out of camera.
Rigid body dynamics can be baked to normal keyframes with Bake To Keyframes in the Object ‣ Rigid Body menu.
仿真稳定性
提高仿真稳定性的最简单方法是增加每秒的步数。但是,必须小心,因为执行太多步骤可能会导致问题,使模拟更加不稳定(如果您需要超过1000步,你应该考虑其他方法来提高稳定性)。
增加解算器迭代次数有助于增加约束,并提高物体堆叠稳定性。
最好避免使用小的物体,因为它们当前不稳定。理想情况下,物体的直径应至少为20厘米。如果仍有必要,将碰撞边距设置为0,虽然通常不推荐,但可以帮助使小对象更自然地执行。
当物体很小和/或移动非常快时,它们可以互相穿过。除了上面提到的内容之外,在这种情况下避免使用网格形状也是很好的。网格形状由单个三角形组成,因此实际上没有任何厚度,所以物体可以更容易地穿过。您可以通过增加碰撞边距给它们一些厚度。
将刚体与其他模拟相结合
由于刚体模拟是动画系统的一部分,它可以影响其它模拟,就像动画系统一样。
为了使其工作,刚体物体需要具有碰撞修改器。只需单击 物理 选项卡中的 碰撞 即可。
缩放刚体
在模拟过程中也可以缩放刚体物体。在大多数情况下,这种方法很有效,但有时会导致问题。
如果不需要动态缩放,则刚体物体应使用 应用缩放 工具 Ctrl-A。