3D Transform Tools

There is no inherent difference between 2D and 3D project files in Motion. At any point, you may decide to start working with groups or layers in 3D. Doing so requires no preplanning on your part; in fact, it’s possible to go back and forth between manipulating objects in 2D and 3D space. This section covers the tools you can use to move objects around in the Canvas.

Figure. Canvas window and HUD showing an image in a 2D layer.

The image in the screen shot above has just been imported into the scene and is positioned at the scene’s origin. Use the 3D Transform tool—located to the right of the Select/Transform tool in the Toolbar—to move the image.

Figure. Toolbar inset showing 3D Transform tool.
To use the 3D Transform tool
  • Select the 3D Transform tool in the Toolbar (or press Q).

Figure. HUD showing controls that appear when an object in a 3D layer is selected.

Two things happen immediately when you select the 3D Transform tool. The onscreen controls change, and the object’s HUD changes.

3D Transform Onscreen Controls

When you select the 3D Transform tool, three colored arrows appear in the Canvas near the center of the image. Each arrow corresponds to one of the three coordinate axes. In the default view, the Z axis points directly out toward you, so that only the tip of the blue Z arrow is visible. Dragging one of the onscreen arrows moves the image along a particular axis.

To move an object using the onscreen controls
  1. Select the object you wish to move.

  2. Drag one of the colored arrows representing the desired axis of movement.

    When dragging, the active arrow turns yellow, and an info window displays the current coordinates of the object as well as the distance the object has moved. As always, coordinates are given in the form of X, Y, and Z.

    Figure. Canvas window showing the 3D transform onscreen controls.

    Near the three colored arrows are three small circles. These are rotation handles. Placing the pointer over any of these circles invokes a rotation ring for a particular axis.

To rotate an object around a single axis using the onscreen controls
  1. Select the object you wish to rotate.

  2. Move the pointer to the rotation handle (small circle) corresponding to the desired axis of rotation.

    The rotation ring appears.

  3. Drag the ring to rotate the object.

    An info window displays the current Rotation values as well as the distance the object has been rotated.

    Figure. Canvas window showing an object rotating around the X axis.
To freely rotate an object around all axes using the onscreen controls
  1. Select the object you wish to rotate.

  2. Place the pointer over any of the rotation handles, then press and hold down the Command key.

    All three rotation rings appear.

  3. Continue to hold down the Command key, and drag anywhere inside the rings to freely rotate the object.

    An info window displays the current rotation values as well as the distance the object has been rotated.

    Important: Rotation performed with the 2D Select/Transform tool is only around the Z axis.

    Figure. Canvas window showing an object rotating along the Z axis in 3D and using the 2D Select/Transform tool.

    Note: When the 3D Transform tool is active, a third set of onscreen controls becomes available: scale handles, which appear on the edges of the bounding box surrounding the selected image.

3D Transform Onscreen Controls Display

It is possible to display a subset of the 3D transform onscreen controls.

  • Press the Comma key (,) to display the axis arrows (but not the rotation handles or scale handles).

  • Press the Period key (.) to display the rotation handles (but not the axis arrows or scale handles).

  • Press the Slash key (/) to display the scale handles (but not the axis arrows or rotation handles).

    When you press any of the above keys a second time, the display switches back to the default, with all three of the onscreen controls visible.

3D Transform HUD Controls

In addition to the onscreen controls, the HUD provides another method of transforming objects in 3D space.

Figure. HUD showing the 3D controls.
  • Move: Three controls in the Move section of the HUD let you drag the selected object in one or more axes at once. Drag inside one of the Move controls to change the relevant parameter values of the object in the Canvas.
    • Move Z: Drag here to move the selected object in the Canvas along the Z axis. Dragging to the right increases the Z value, and dragging to the left decreases the Z value. Hold down the Command key when dragging to simultaneously scale the object as it is translated (moved), preserving its size relative to the camera.
    • Move XY: Drag here to move the selected object in the Canvas along the X and Y axes. Dragging right or left increases or decreases the X value. Dragging up or down increases or decreases the Y value. Using this control is identical to moving a 2D object directly in the Canvas. Hold down the Command key when dragging to constrain movement to the axis corresponding to the initial direction of the drag.
    • Move XZ: Drag here to move the selected object in the Canvas along the X and Z axes. Dragging right or left increases or decreases the value of X. Dragging up or down increases or decreases the value of Z. Hold down the Command key when dragging to constrain movement to the axis corresponding to the initial direction of the drag.

      Tip: As in the Inspector, holding down the Shift key while you drag in the HUD makes larger changes. Holding down the Option key while you drag makes smaller changes.

  • Rotate and Scale: Two additional drag controls in the HUD let you rotate and scale the selected object in the Canvas:
    • Rotate XYZ: Drag here to rotate the selected object in the Canvas around all axes. Starting at the origin, dragging up and down rotates the object around the X axis. Dragging to the left and right rotates the object around the Y axis. Hold down the Command key while dragging to constrain rotation to the Z axis.
    • Scale: Drag here to uniformly scale the selected object in the Canvas. Dragging to the right or up (or both) increases the Scale value. Dragging to the left or down (or both) decreases the Scale value. Hold down the Command key while dragging to constrain scaling to the axis corresponding to the initial direction of the drag.

Relative Coordinates

To better understand the concept of relative coordinates, think of a system of satellites, like the earth, the moon, and the sun. The moon’s parent is the earth, and the earth’s parent is the sun. Usually, when considering these three bodies, the moon’s position is described in terms of its position relative to the earth (the moon’s parent), and the earth’s position is described relative to the sun (the earth’s parent). In Motion, an object’s position and orientation are always relative to its parent.

When you add a new group to a Motion project, that group is created at the origin coordinates of its parent. In the case of a root-level group (a group that is not nested within any other groups in the Layers tab), the parent is the project itself. An object placed inside of a group has its position described relative to its parent: the group.

Figure. Canvas and Inspector showing a group placed at coordinates: X=50, Y=50, Z=50.

In the previous example, a group has been positioned at X, Y, and Z coordinates of 50, 50, and 50, respectively. The group is located 50 units away from its parent’s origin on all axes (the parent in this case being the project itself). The image inside the group is positioned at 0, 0, 0. Because the image’s position is relative to its parent, the group, it shares its parent’s origin and has an apparent position in the world of 50, 50, 50.

Moving the image to a position of 25, 25, 25 displaces it by 25 units from the group’s origin in all axes. While the image’s apparent position relative to the world is 75, 75, 75, its Position values in the Inspector are 25, 25, 25 because its position is always relative to its parent.

Figure. Canvas and Inspector showing image in a group at coordinate: X=25, Y=25, Z=25.

Rotation values are also relative to an object’s parent.

Figure. Canvas showing a group with Z Rotation set to 45 degrees and an image with Z Rotation set to 90 degres inside a group set to 45 degrees.

Important: World and view transforms are limited to the HUD and onscreen controls; all transforms made in the Inspector are relative to an object’s parent’s space.

Layer Order and Depth Order

When compositing in 2D, the Layers tab shows the layer order, which determines which objects appear on top of other objects. Objects that are higher up in the Layers tab appear on top of objects lower than them in the Layers tab.

Important: The children of 2D groups are always composited in layer order.

Figure. Layers list and Canvas showing how layers in the Canvas match the top-to-bottom arrangement in the Layers list.

If you were to move Group A below Group B in the Layers tab, Group B would be rendered on top of Group A.

Figure. Layers tab and Canvas showing the layers reversed in both Layers tab and Canvas.

The Layers tab also shows object relationships in terms of parenting. The parent-child relationship is displayed in the Layers tab through the use of indenting and disclosure triangles.

Figure. Layers list showing how groups are the parents of the items within them.

The Layers tab is not the only indicator of order when considering objects in 3D. When depth-sorted, an object can be at the bottom of the Layers tab and yet appear to be on top of everything else in the Canvas, because of the object’s position relative to the current camera. The most common way to adjust depth order is to change the Z position of a layer or group.

Important: The children of 3D groups are composited in depth order by default.

Figure. Layers list and Canvas showing objects in 3D groups where the order in the Canvas doesn't match the order in the Layers list.

With the 3D groups above, objects are composited in depth order; their position in the Layers tab does not correlate to their position in 3D space relative to the camera.

In the above example, the Blue A group is above the Red A group in the Layers tab but it appears behind the Red A group in the Canvas because it is depth-sorted. The same principle applies to the Blue B group and the Red B group.

3D Transformations in 2D Groups

All objects have 3D transformations available, even when in 2D groups. All can be rotated around any axis and moved along any axis. Keep in mind that objects in 2D groups are not depth-sorted, and cannot intersect, regardless of their position in 3D space.

Figure. Layers list and Canvas showing groups sorted in layer order.

Both of these groups are positioned at the same point in 3D space, but because they are layer-ordered, group A does not intersect with group B. If you change the parent group to 3D, the two groups will intersect.

Figure. Layers list and Canvas showing groups sorted in depth order.

Note: If two groups are coplanar (occupy the same plane), they are composited in layer order, regardless of whether the objects’ parent is a 2D group or 3D group. In a 2D composite, all objects are coplanar.