Aerodynamics¶
Aerodynamics parameters are the Form Drag, the Skin Drag, and the Lift coefficients. Aerodynamic coefficients produce explicit forces and combine the effects of the speed of the flow and air density. These parameters are dimensionless.
When at least one of these three parameters is different from zero, a Carbon dynamic object will interact with any vector field provided within a Carbon Flow (currently not available) node that is attached to the simulation.
Note
- The Carbon Flow (currently not available) will affect all of those Carbon dynamic objects even when the flow source (Uniform Field, Vector Field, or VDB volume) contains only 0 values.
- Before setting up the aerodynamics parameters in your scene, you should always make sure that the global Simulation Damping is set to zero. This is simply because the global Simulation Damping is similar to an aerodynamic force (with uniform factors and zero wind velocity) and would affect the aerodynamic forces being set up.
Form Drag¶
Out of the three aerodynamics parameters (Form Drag, Skin Drag and Lift), Form Drag, is the most important. It reflects the impact of the wind to the main cross section (as with a head wind), and therefore the form/shape of an object heavily influence the outcome.
Note
This is the first aerodynamics parameter to set up. Adjust the Form Drag value until a satisfactory result is achieved. Using real world scale, meaningful values should usually be between 0 and 0.2.
Skin Drag¶
The Skin Drag represents the friction of the object with the air flow and is always smaller or equal to the Form Drag and often very much smaller.
If the Skin Drag is equal to the Form Drag, then a motion damping behavior is created in similar fashion to the global Simulation Damping.
Note
Since the value for the Skin Drag is always smaller to the Form Drag, it makes more sense to only set its value after that the desired Form Drag value has been found.
Lift¶
Lift represents the impact of the air in a lifting capacity. Think of it as the air under a wing of an air plane. It helps to keep objects “floating” in the air and makes them appear lighter.
Lift is usually set to a value lower than Form Drag and Skin Drag.
Note
Lift is not usually required for cloth, and is almost exclusively used in a special effect capacity. For this reason, it is always best to set the Lift value last.