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MotionAtelier

Quickstart

This walk-through turns a plain two-key move into a bounce, and shows the steps used for every shape.

You need: a Houdini scene with one animated parameter that has two keys with different values, for example tx keyed at frame 1 (value 0) and frame 24 (value 10). Install MotionAtelier and open the panel first.

1. Read the keys

Section titled “1. Read the keys”
  1. Open a Channel Editor and select the two keys of the move.
  2. In MotionAtelier, press Get Keys.

The existing motion appears as an editable Ease curve, normalised to 0–1 in time and value. The status line reports what was read, for example Get Keys: 2 keys from /obj/geo1/tx (graph). The scene is not changed.

Get Keys is optional: the generated shapes (Bounce, Elastic, Wave, Noise) do not need it. Use it when you want to start from the motion you already have. How keys are read is described in Houdini integration.

2. Shape the curve

Section titled “2. Shape the curve”

Edit the curve directly, or pick a generated shape.

  • Edit by hand: drag a knot or a tangent handle in the graph. Click VIEW ▸ Velocity to edit speed instead of value. See Curve editor.
  • Use a generator: set SHAPE to Bounce. Its parameters, Bounces and Elasticity, appear in the Motion Stack tab on the right. Change them and the graph updates.
Bounce with two Elasticity valuesTwo bounce curves. With Elasticity 0.5 the rebounds are low and short; with 0.8 they are much higher and last longer.
  • Bounce, default parameters
  • Elasticity 0.80
Raising Elasticity keeps more energy in each rebound. Plotted from MotionAtelier 0.4.2's own curve code, outside Houdini. An illustration of the curve, not a screen capture.

Every change here is local to the panel. The status line keeps saying scene unchanged until you commit.

3. Preview

Section titled “3. Preview”

Press Play under the graph. A marker runs along the curve; Preview duration sets how many seconds one pass takes. The preview runs in the panel only and does not move the Houdini timeline. See Preview.

4. Commit

Section titled “4. Commit”
  1. Make sure the keys are still selected in the Channel Editor. Commit Keys reads the selection again when you press it, so you can also select other keys or channels now.
  2. Leave Apply To on Apply to each interval (the left button). With two keys there is only one interval.
  3. Press Commit Keys.

The status line reports the result, for example:

Commit Keys: committed; 1/1 channels; 1 intervals; keys 2 reused + 6 created − 0 removed

The two original keys keep their frames and values. Six new Bezier keys between them reproduce the bounce. Scrub the timeline to see it.

5. Undo or keep

Section titled “5. Undo or keep”
  • Undo: use Houdini’s Edit ▸ Undo. The whole commit, on every channel, is one undo step named MotionAtelier: Commit Bounce.
  • Keep: the curve is now in History. Open the Recipes tab and press History to see it, or save the shape as a recipe with Save Current as Recipe from the recipe list’s right-click menu. See Recipes and History.

Next steps

Section titled “Next steps”