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How to Make a Rigged Character Move Along a Straight Path Instead of an Automatic Arc

To move a rigged character in a straight line, animate its travel control between two positions, align the translation keys in time, and use Linear tangents for an initial test. If the character still curves, inspect its parent transforms and any motion-path connection.

This guide is for animators who have a working character rig but see an unwanted arc between their start and end poses. The worked steps use Maya. The goal is to straighten the character’s overall travel while retaining its separate pose animation.

October 29, 20267 min readBy Metlivi Editorial Team

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Section 1

Identify Whether the Problem Is the Route or the Speed

A straight route and constant speed are separate requirements. A character can follow a straight line while gradually accelerating, or follow a curved route at constant speed. Adobe’s documentation explicitly distinguishes spatial interpolation, which controls movement through space, from temporal interpolation, which controls changes over time. That distinction helps identify which part of the animation needs adjustment. Keyframe interpolation in After Effects

First, choose the point whose path should be straight: the travel control’s origin, a root joint, or another clearly defined rig point. Watch that same point throughout the move. A rotating or posing character can have curved trajectories at its extremities even when its overall travel is straight.

Use this diagnostic sequence before changing the animation:

What you observe	What to inspect first
The travel point bows away from the intended line	Translation curves and intermediate keys
The route is straight, but movement speeds up or slows down	Timing and tangent slopes
Translation curves look linear, but the point still arcs	Parent transforms or another driving connection
The travel point stays straight while other parts curve	Local pose animation and rig evaluation

Section 2

Choose the Control That Actually Moves the Whole Character

Start with the rig’s designated travel control. Its name and purpose depend on the rig: a control called “global” may handle placement, while another control handles animated travel. Test the intended control with a small temporary translation, inspect the result, and undo the test.

Confirm that the character’s visible parts and relevant controls follow together. If some controls stay behind, establish how the rig expects them to follow before creating travel keys. Editing an arbitrary joint or the visible mesh makes the test harder to interpret.

Also inspect the control’s parent hierarchy. Maya objects can inherit transformations from their parents. Consequently, a straight local translation beneath an animated rotating parent can produce a curved world-space trajectory. This is a consequence of combining the inherited transform with the local animation. Maya inheritTransform command

For the initial test, use a travel control whose parent transforms remain fixed over the interval. Work in a saved copy if you need to temporarily isolate existing animation. Record the original values rather than zeroing controls whose offsets may be part of the rig setup.

Section 3

Build a Clean Two-Key Translation Test

Use two endpoint keys to establish whether basic translation behaves correctly. The following values are illustrative scene units, not measurements from a particular character. They assume an editable travel control in a fixed coordinate frame, with no other connection driving its translation.

Frame	Translate X	Translate Y	Translate Z
1	0	0	0
25	6	0	0

In Maya, create the test as follows:

Select the travel control and move the Time Slider to frame 1.
Enter the starting translation values in the Channel Box.
Select the Translate X, Translate Y, and Translate Z attribute names, right-click, and choose Key Selected.
Move to frame 25 and enter the destination values.
Key the same three translation attributes again.
Inspect the interval for existing translation keys. In the test copy, remove only intermediate keys that conflict with this intended move, preserving unrelated pose animation.

Maya supports keying individual attributes or selected groups of attributes through the Channel Box. Using Key Selected makes the scope of this test explicit. If your control starts at nonzero values, retain those offsets and add the desired displacement to the appropriate axis. Set keys in the Channel Box

Section 4

Apply Linear Tangents to the Translation Keys

Open Maya’s Graph Editor with the travel control selected. Display its translation channels, select the endpoint keys on those channels, and choose Tangents > Linear. Apply the change to all translation channels involved in the move. Maya documents Linear tangents as straight animation-curve segments between keys. Graph Editor toolbar, Keyframe Tangent Marking Menu

For the sample move, X should increase steadily while Y and Z remain unchanged. Scrub through the interval instead of checking only the endpoints. A character can reach the correct destination while departing from the intended route in between.

For diagonal movement, give every changing translation channel the same start and end frames. For example, moving from (0, 0, 0) to (6, 0, 3) with synchronized linear interpolation produces a straight diagonal in that coordinate frame. If X finishes earlier than Z, the combined trajectory changes direction.

Apply Linear tangents selectively. Converting every key on the rig would also change pose timing that does not need correction. Autodesk distinguishes Linear, Spline, Flat, and other tangent types because they produce different transitions between keyed values. Keyframe Tangent Marking Menu

Section 5

Verify the Result with a Motion Trail and a Midpoint Check

Create a Motion Trail on the travel control to inspect its trajectory. In Maya’s Animation menu set, open Visualize > Open Motion Trail Editor, select a suitable display range, and click Create Motion Trail with the animated control selected. The documented workflow includes a Before and After display mode for inspecting movement around the current frame. Create and edit a Motion Trail

Use the sample values to make a numerical check. Frame 13 lies halfway between frames 1 and 25, so the expected translation is (3, 0, 0). For the diagonal example, it is (3, 0, 1.5). These are calculated expectations for synchronized linear interpolation, not reported software test results.

The general check is P(u) = A + u × (B − A), where A is the starting position, B is the destination, and u is progress from 0 to 1. At one-quarter progress, the position should be one-quarter of the way along the segment. This checks both direction and spacing.

Inspect from more than one fixed viewport angle so that depth changes are visible. Remember that a Motion Trail displays the resulting movement; it is distinct from a motion path that drives an object along a prescribed route. Preview animation with Motion Trails

Section 6

Diagnose an Arc That Remains After Linear Interpolation

If the two-key test still curves, inspect what contributes to the final position. First check the parent hierarchy over the full interval. A parent can rotate between identical-looking endpoint orientations, so inspect intermediate frames as well. Use the rig’s intended travel space rather than changing transform inheritance without understanding the setup. Maya inheritTransform command

Next, check whether the control is attached to a motion path. Maya path animation moves an object along a defined three-dimensional route, and its documentation treats reshaping that route and changing movement speed as separate operations. If the route itself is curved, changing timing alone will not straighten it. Edit the route into a straight segment or use the rig’s supported direct-translation workflow. Path Animation

Finally, compare the travel control’s trajectory with the particular joint or control that appears to arc. Rig evaluation can produce different intermediate results. For example, Autodesk documents that HumanIK’s global IK effectors and hierarchy-local FK effectors do not interpolate identically. A straight travel control therefore does not establish that every rig point will follow the same route. HumanIK Controls

Section 7

Add Easing Without Reintroducing the Curve

Once the route is verified, decide whether the character should maintain constant speed or ease into and out of the move. For travel along X alone, keep Y and Z fixed and adjust only X’s timing. Changing progress along that single axis cannot create sideways displacement while the coordinate frame remains fixed.

For diagonal travel, all changing coordinates must share the same normalized progress. In the expression P(u) = A + u × (B − A), easing changes how u advances over time. Editing each coordinate’s easing independently can break that relationship and bend the route. This is a geometric condition derived from the straight-line equation.

Finish by checking the complete rig with its intended pose animation active. Confirm the endpoints, intermediate positions, and travel trail across the whole interval. Keep the verified travel motion as your reference while refining the character’s local movement.

Section 8