Tutorial 5: Motion Flow Editing

Lesson 5: Using the Create Random Motion Feature

This lesson illustrates how to use the Create Random Motion feature with clips in the Motion Flow Graph to create interesting scenarios quickly. It uses an available set of .bip motion files.

You'll add four skating motions to the Motion Flow Graph, create a network of transitions, and generate a random script to animate the biped.

Creating a biped

  1. Reset 3D Studio MAX.

  2. Create a biped.

  3. On the Motion panel, on the General rollout, turn on Motion Flow mode.

  4. On the Motion Flow rollout, click Show Graph.

    The Motion Flow Graph displays.

  5. On the Motion Flow Graph toolbar, click Create Multiple Clips.

  6. From the cstudio\tutorials\tutorial_5 directory, select the following four motion files: skateup.bip, skatestart.bip, skateloop.bip and skatespin.bip. Click OK.

    The motion files load into the Motion Flow Graph.

  7. On the Motion Flow Graph toolbar, turn on Move Clip.

  8. Arrange the clips in a column with skateup at the bottom, then skatestart, skateloop, and skatespin.

  9. On the Motion Flow Graph toolbar, turn on Create Transition.

  10. In the Motion Flow Graph window, click and drag from one clip to the next to create transitions between the clips. Start with skateup and drag to skatestart, then skatloop and finally skatespin.

    Use the illustration as a guide to create the transitions. To create a loop, click a clip twice.

  11. Turn on Select Clip/Transition and region select all the transitions, and then click Optimize Selected Transitions on the Motion Flow Graph toolbar.

    Optimize creates high quality transitions.

  12. On the Motion Flow Graph toolbar, turn on Show Random Percentages.

    A percentage number displays next to each transition. You'll alter the percentage for the loop transition and the transition between skateloop and skatespin.

  13. In the Motion Flow Graph window, right-click the loop transition on the skateloop clip.

  14. On the upper left of the Transition Editor dialog enter 85 in the Probability field. Click OK.

  15. In the Motion Flow Graph window, right-click the transition from skateloop to skatespin. On the Transition Editor dialog, enter 15 in the Probability field. Click OK.

    When a random script is generated skateloop will be chosen over skatespin 85 percent of the time. The percentage numbers in the Motion Flow Graph are normalized, so if two transitions from a clip are set at 100, each one has a even chance of being selected.

  16. On the Motion Flow Graph toolbar, turn on Select Random Start Clips, and click skateup.

    The skateup clip will always be the first clip to play when a random script is created.

  17. Close the Motion Flow Graph window.

  18. On the Motion Flow Script rollout, click Create Random Motion.

  19. In the Minimum Animation Length field, enter 2000 and click Create.

    A random script is generated. Click Play to view the results. The skater gets up off the ice and begins skating. Once the script reaches the skateloop clip it loops back to skateloop 85 percent of the time and skatespin 15 percent of the time.

    Select the biped Center of Mass and turn on Trajectories on the Display rollout, to get a birds eye view of the entire motion.