In the previous scene, no solver was present, so no simulation was done. In this step, we will add an ODE solver in the Root node of the simulation. We provide several ODE solvers, with different integration schemes. Take a look at our tutorials on Solvers later.
We will use the classic explicit euler solver EulerSolver to update particle positions and velocities at each time step. In SOFA, a solver acts on all the object placed below in the hierarchy.
This time, when you animate the scene, the particule falls along the direction of the gravity.
The gravity is specified in the root node of the simulation. We use a default value of (0, 0, -9.81).
This opens the components for this node, and allows you to edit them. We won't make any changes for now.
Changing the gravity on child nodes of the simulation will not do anything as at each time step the gravity, and other parameters, (time, dt...) is overwritten using the value specified in the root node.
The component Gravity lets you specify a particular gravity for a node and all its children.