Charges
The term “charge” is commonly used in electronics to refer to the property of an object that determines its electromagnetic interactions. However, in a broader context, this term can be adapted to represent different physical quantities depending on the specific domain of application.
The OpenPLX Physics concept of a Charge is an entity which gives an Interaction an attribute to compute interaction forces. The charge is commonly defined as an attribute in a Body definition. E.g. a ContactGeometry or a local frame of reference, in OpenPLX called MateConnector. Mate interactions like hinge joints, ball joints, prismatic joints etc. are two-body interactions, which require two MateConnectors in the charges array attribute to be complete and valid.
ContactGeometry
A concept valid for both 2D and 3D physics, also 1D physics where the only type is a line geometry of variable length and position. A ContactGeometry owns one Material attribute, which define the internal material properties of the geometry.
Material
Material defines properties of a homogenous isotropic material. Note that for defining the interaction at contact between two contact geometries a SurfaceContact.Model has to be declared given two materials.
The materials defined with OpenPLX Physics are const, meaning that once they are defined, their internal properties are not possible to update from elsewhere.
| property | description | unit |
|---|---|---|
| density | Mass per length unit to the power of the physics dimension | 1D - [kg / m], 2D - [kg / m^2], 3D - [kg / m^3] |
| youngs_modulus | Compressive stiffness | [N / m^2] |
These properties are clearly not enough to define a real material that can flex or break. Expect future types, such as ElastoPlasticMaterial or ViscousMaterial.
To learn how to use materials, see