Example - Baking Simulations

Our simple scene has five objects that have all been assigned Bullet dynamics. The objects fall to the floor and bounce and roll around beautifully. To ensure the integrity of their motion, to not have to endure the time taken to repeat the Bullet calculation (which in this case is admittedly negligible) and to be able to export the scene to another piece of software we will bake the motions that the objects make.

To do this, select all the objects you wish to bake - in this case the five objects dropping to the floor. There is no need to bake the floor, there is no animation applied to it.

On Layout’s I/O tab you will find MDD Multi-Baker in the Export group. There are plenty of settings you can change for a variety of situations but for this exercise we will immediately hit OK. You may be prompted to create a VertCache directory in your content directory. Do so, this is where the MDDs will be stored.

Further up the I/O tab, in the Import group you will find MDD Multi-Loader. Before opening it, we turn off Enable Dynamics in the FX Tools tab and press play to assure ourselves that the objects in the scene no longer fall to the floor. Now we return to the MDD Multi-Loader and open it. The window contains the six objects in our scene, the five falling shaped and the inanimate floor. On the right side we can either load the MDDs by multiselecting them in the load requester or by hitting the Scan MDDs button and navigating to the right folder. In either case, we rapidly get five MDDs in the right window.

We can go through the objects one by one, carefully selecting the appropriate MDD file to go with the right object, or we can just hit Match By.... By default the choice is set to Names, which is fine. In either case, we will see that we have one MDD assigned to each of the five falling shapes and none to the floor. Now when we hit OK to close the window and press play on the scene we see our five shapes falling to the floor object exactly as they did when Dynamics were enabled on the FX Tools tab.