Backward Compatibility with Version 6.3 and Earlier
Quaternion Variables
In the Attachment, Average Rotation, Rigid Connector, and Rigid Material nodes in 3D, the internal dependent variable for the quaternion has been modified in order to be safely initialized with a zero solution. When opening an old model, this rescaling is done automatically to maintain full compatibility.
When building a model using the API, the new behavior will be used. This is true even if, for example, a Java file created from an older version is used.
If you, in the solver sequence, have manually changed the scale of the DOF for the quaternion defined by an Average Rotation node, you need to replace lines similar to
model.sol("sol1").feature("v1").feature("comp1_solid_avgr1_q")
.set("scaleval", 1);
with a line similar to
model.sol("sol1").feature("v1").feature("comp1_solid_avgr1_qd").set("scaleval", 1);
For Attachment, Rigid Connector, and Rigid Material, you only need to update existing code if you have deselected grouping of ODE variables in the physics interface (this is on by default). In that case, you need to replace lines similar to
model.sol("sol1").feature("v1").feature("comp1_solid_att1_a")
.set("scaleval", 1);
model.sol("sol1").feature("v1").feature("comp1_solid_a_rig1")
.set("scaleval", 1);
model.sol("sol1").feature("v1").feature("comp1_solid_rd1_a")
.set("scaleval", 1);
with lines similar to
model.sol("sol1").feature("v1").feature("comp1_solid_att1_a0")
.set("scaleval", 1);
model.sol("sol1").feature("v1").feature("comp1_solid_a0_rig1")
.set("scaleval", 1);
model.sol("sol1").feature("v1").feature("comp1_solid_rd1_a0")
.set("scaleval", 1);
Spring–Damper
In the Spring–Damper node, available in the Multibody Dynamics interfaces, the energy dissipated in the damper is computed only when it is indicated in the Energy Dissipation section in the settings of the physics interface.