Optional module - Maxon Computer

148 CINEMA 4D R11 Quickstart – Dynamics
If we play the animation now we will have a similar situation to the one we had in the previous chapter: The
polygon object will fall out of the picture. We must set a zero value for the mass. But where? We will use the
“Set Soft Mass“ from the “Dynamics“ menu. We will set the mass value of a point on the torus to “0“ which
will keep this point in place (since it will possess no virtual weight) and the rest of the torus will follow the laws
of gravity.
To do this, select one or more of the top points of the torus in the point mode and select Dynamics / set soft
mass. Change the mass value to 0 and click on “OK“.
Finally, change the integration method of the solver object from “Adaptive“ to “Softbody“ and start the
animation again.
We’re done! The torus has a virtual hook and swings to and fro when you push it.
There’s not much we can say about the state of the physics of the polygon body but we can say a little about its
physical state. The torus has assumed the properties of a rubber-like mass and will behave according to gravity
and the properties we gave it. In the second part of this tutorial we only showed one of the many possibilities
soft body makes possible. The variations are virtually limitless. Now we’ll come to the part that will improve
your workflow.
6. Tips & Tricks
Always set the editor’s frame rate to “All Frames“ (Animation / Frame Rate / All Frames). This function makes
sure that every image of the Dynamics simulation will be visible and none will be suppressed since CINEMA 4D
tries to adhere to the predefined amount of frames.
Depending on their complexity, Dynamics simulations can take very long to calculate and can place high
demands on our CPUs. There are a couple of methods to achieve the same result without forgoing the smooth
depiction in the editor window. A smooth depiction can save a lot of time in the “testing phase“.
It’s better if you use less-complex polygon objects and define them as sub-objects of a HyperNURBS object. In
most cases the result will remain the same. The simulation of the soft body springs, for example, will be much
more fluid since only a few springs will be used in the Dynamics simulation.
Bake the Dynamics simulation. This will transform the simulation into keyframes which has the major advantage
that it will be depicted much smoother in your editor window and you can intervene and move or delete
keyframes or even completely change a part of your simulation as you desire.
You can also use negative collision fields instead of collision. This method is calculated faster and delivers the
same result in most cases. Try the settings “Ellipsoid“ or “Box“ and see how they change your simulation. These
settings are faster and often deliver the same result here as well.
If your objects still pass through the plane simply increase the oversampling rate of the solver object. A value of
4, for example, means that Dynamics will calculate four additional images between each frame. An oversampling
rate of 8 will result in twice the amount of images between frames, and so on. The higher the value, the higher
the probability a collision will be calculated correctly. Of course the frame rate will suffer with each increase
in oversampling.