Animating the Pen on the Path

Animating a Pen

Creating Explosions

 

Autodesk 3ds Max Tutorials > Animation Tutorials > Animating a Pen > 

Creating the Line Using PathDeform

The PathDeform modifier takes an object and stretches it along a path. By animating the amount of stretch, you can use it to create the effect of a line growing over time.

1. Continue from before, or choose File > Open, then open tutorials\intro_to_animation\ write_on_growline.max.
2. From the Create menu, choose Standard Primitives > Cylinder.
3. On the Object Type rollout, turn on Auto Grid.
4. Drag out a cylinder over the start of Line01. It doesn't have to be very wide.

   

   Create a cylinder over the start of the line.

5. In the Parameters rollout, set the following values:
   • Radius=0.03
   • Height=9.2
   • Height Segments=133
   • Sides=4

   These values will give the cylinder enough segmentation to stretch over the path. Before you create the path deform, you'll hide the paper, so it'll be easier to see the new object.

6. Select the paper in the viewport, then right-click and choose Hide Selection from the quad menu.

   The paper disappears from view.

7. Select the Cylinder, and then on the menu bar choose Modifiers > Animation Modifiers > PathDeform.

   The Path Deform rollout parameters appear in the Modify panel.

8. On the Parameters rollout, click Pick Path, then click the line in the viewport.

   The cylinder deforms in the viewport into the first few bends of the letter Y. However, it is rotated along its Z axis. Later, you’ll rotate the cylinder so that it lies on top of the line.

9. Move the time slider to frame 0, right-click and choose Move from the quad menu. Using the Transform gizmo, raise the deformed cylinder up in Z until you can see it clearly.

   

   The deformed cylinder has the wrong orientation.

10. With the modified cylinder still selected, turn on Select And Rotate.
11. Use the orthographic Left, Front, and Top views to position the modified cylinder so it aligns with the original Line0 object.

    

    Tipping over the cylinder in the Left view

    

    Finish leveling the cylinder in the Front view.

    

    Align the cylinder with the animation path in the Top view.

    Tip In the Top viewport, you might also want to move the cylinder a bit so it aligns well with the path.

    

    Cylinder aligned with path in the Camera01 viewport

    Next, you'll keyframe the stretch so the line grows.

Make the ink black:

1. Press M to open the Material Editor.
2. Locate the inky black material, and drag from its sample slot to the modified cylinder, Cylinder01.
3. Close the Material Editor.

Set up the scene for the final animation:

1. Right-click a blank area of a viewport, and choose Unhide All from the quad menu.

   The paper is visible once again.

2. Press H to open the Select Objects dialog. Choose Line01, and then click Select.
3. Right-click Line01, and choose Hid Selection from the quad menu.

   The animation path is now hidden.

Keyframe the stretch:

1. Make sure you are at frame 0, then turn on the Auto Key button. Set the Stretch to 0.0.
2. Move to frame 100, then adjust the stretch so it coincides with the end of the pen. Try a Stretch value of about 1.0.
3. Move the time slider to frame 0, and play the animation.

   

   

   

   Pen writes onto the paper.

   You'll notice the line and the pen are not in perfect synchronization. If you want to take the time, you can fix this by completing these steps:

4. With Auto Key still turned on, go to frame 0.
5. Move forward one frame at a time by clicking Next Frame. Whenever you see the path out of sync, adjust the Stretch value.
   TipUse the spinner to adjust the Stretch value.
6. Repeat step 5 until you reach frame 100.

   If you don’t want to adjust Stretch one frame at a time, you can open write_on_yes_anim_complete.max to see the finished result.

   NoteThere are more mathematical ways to synchronize the animations, such as applying a Normalize Spline modifier to the line, but for an artist this method gets the job done using visual means.
7. Save your work as mywrite_on_yes_anim_complete.max.