In these steps you model a 2D curtain rod from a plane and attach hair to it. Then you add and keyframe a sphere in the scene to later be used as a collision object.

To create the curtain using Hair

1. To create a NURBS plane, select Create > NURBS Primitives > Plane, then click-drag in the scene to create a plane.

   (If you have previously shut off the interactive primitive creation option, simply click once in the scene to create the primitive at the origin.)

2. Using the Scale Tool , resize the plane in the X direction as shown in the image below.

   

3. With the plane selected, select Hair > Create Hair > , set the following options and then click Create Hairs:
   • Output to NURBS Curves
   • U Count to 20, V count to 1
   • Passive fill to 0
   • Randomization to 0
   • Points per hair to 12
   • Length to 10
   • Turn off the options Create Rest Curves, Edge Bounded and Equalize

   Hair is created and attached to the plane.

   

4. Select the plane and, using the Rotate Tool , rotate the plane so the hair appears to be on the underside of the plane. Then, using the Move Tool , move the plane up the Y axis so the bottom of the hair just touches the ground plane, as shown in the following image. (Ensure you do not select the hair when selecting the plane.)

   

5. Create a directional light ( Create > Lights > Directional Light) and do the following:
   • Move the light above and to the left of the curtain.
   • Rotate the light so it aims at the curtain.
   • In the light’s Attribute Editor ( + a) go to the Directional Light Attributes section and change the Intensity value to 1.5.
6. Create a NURBS sphere ( Create > NURBS Primitives > Sphere) and move it along the Z-axis so it’s in front of the curtain.

   

7. To set the start keyframe for the sphere, do the following:
   • Go to frame 1 on the Time Slider.
   • In the Channel Box, drag to select the Translate X, Y, and Z channels.
   • Right-click the channels and select Key Selected.
8. To set the keyframe for the sphere and move it through the curtain, as in the image below, do the following:
   • Go to frame 100 in the Time Slider.
   • Move the sphere in the Z direction as shown in the image below.
   • In the Channel Box, select the Translate Z channel.
   • Right-click the channel and select Key Selected.

     

9. Rewind the Time Slider to 0 and play the animation.

   The sphere passes through the curtain as though the curtain weren’t there. In the next steps you set the sphere as a collision object with the hair.