Path Constraints in 3ds Max - Time & Speed

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  • Design Visualization
  • Animation
  • 2011
  • Basics
  • 3ds Max
Skill Level
  • Beginner
3 min

Path Constraints in 3ds Max - Time & Speed

In this tutorial, learn how to control the timing and speed of a constrained object. In this example, the object you are constraining is a car. Through this tutorial, you will learn how to constrain the path to its predefined path so it adheres to basic traffic rules.

  • Recorded in: 3ds Max 2010
  • This tutorial is intended for use with 3ds Max version 2010 or higher.
00:00:00 --> 00:00:07
When you constrain an object to a path, the object is moved with its
pivot point aligned to the starting point of the spline.

00:00:25 --> 00:00:30
You can then move the path in the scene to prevent any problems
such as a car sunk underground.

00:00:34 --> 00:00:40
Once an object is constrained to a path, it moves along that path
at a constant speed. This is the default setup.

00:00:40 --> 00:00:45
Sometimes you need to control timing, in this case to have the car
respect red lights and avoid jaywalkers.

00:00:45 --> 00:00:50
An easy way to achieve this is to start by deleting the two keyframes
that the Path Constraint tool created.

00:00:50 --> 00:00:55
These two keyframes represent percentage of travel along the path,
from 0 to 100.

00:00:55 --> 00:01:01
From that point on, turn on Auto Key mode. Scrub along the timeline
to a point right after the light turns red.

00:01:01 --> 00:01:05
As you move the car to the intersection, notice that the car only
moves along the path.

00:01:05 --> 00:01:07
All other directions are restricted.

00:01:08 --> 00:01:12
To make the car pause at the red light, copy the last key to a point
right after the light turns green.

00:01:13 --> 00:01:17
A copy is made by pressing the Shift key and moving the keyframe
along the timeline.

00:01:18 --> 00:01:22
Move the car again and make it stop before it hits the jaywalker.

00:01:28 --> 00:01:33
Make it pause again for a few frames by copying the keyframe along
the timeline.

00:01:36 --> 00:01:41
Finally, move the car along the end of the path towards the end
of the animation.

00:01:45 --> 00:01:51
As you play back the animation, you'll notice that although
the timing is right, the motion of the car is unnatural.

00:01:51 --> 00:01:55
The stop and go motion is rigid and lacks acceleration and deceleration.

00:01:55 --> 00:01:58
This can be adjusted in the Curve Editor.

00:01:58 --> 00:02:02
With the car selected, the Curve Editor can be accessed
with a right-click.

00:02:02 --> 00:02:08
In the Curve Editor, notice how linear the graph is.
This is because the Percent track is set to a Linear Float controller.

00:02:08 --> 00:02:14
With a right-click, you can choose to assign a different
controller type to it, this time choosing Bezier Float.

00:02:15 --> 00:02:18
Now you have nice curves representing acceleration and deceleration.

00:02:20 --> 00:02:23
You can make changes to the handles to fine-tune the timing.

00:02:32 --> 00:02:35
Play back the animation and notice the improvement.
Posted By
  • 3ds Max
  • Animation
  • 2011
  • Basics
1 Comment
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| 2 years ago
Very nice place for learning concept of 3d
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