Create a sphere traveling through a tube using the Conform modifier

Create the conform object

In this example, a cylinder acts as the conform object.

1. Create a cylinder (Cylinder001).
2. In the Parameters rollout, set the following values:
   • Radius: 40
   • Height: 600
   • Height Segments: 120
   • Sides: 50
3. Select the Rotate tool.
4. Select the Transform Type-in (Edit > Transform Type-in) and set Absolute:World X value to 90.
   This positions the cylinder on its side.

   

Create the target object

In this example, a geosphere acts as the target object, travelling through the cylinder.

1. Create a geosphere (GeoSphere001).
2. In the Parameters rollout, set the following value:
   • Radius: 55.0
   

Create an animation

1. In the Animation and Time Controls, turn on Auto Key mode.
   
2. Drag the time slider to 50.
3. Move GeoSphere001 to the opposite end of Cylinder001.
   
4. Drag the time slider back to 0.

Add an Edit Poly and Vol. Select modifier

1. Select Cylinder001.
2. In the Modify panel, select Edit Poly from the Modifier List.
3. In the Modifier stack, select Polygon sub-object mode.
   
4. Delete the end caps of Cylinder001.

   Now the cylinder is open, allowing the sphere to run through it.

5. Select all the remaining faces of Cylinder001.
   
6. In the Modify panel, selectVol. Select from the Modifier List.
7. In the Parameters rollout, set the following values:
   • Stack Selection Level: Vertex
   • Select By: Mesh Object; click the None button to select Geosphere001 in your scene.
   
8. Select GeoSphere001.
9. Play the animation.
   As the geosphere moves through the cylinder, vertices from Cylinder001 that are inside GeoSphere001 are selected.

   Tip: Turn on Wireframe Override in the Per-View Preference Viewport Label menu to better view this selection.

   

Add a Conform modifier

1. Select Cylinder001.
2. In the Modify panel, select Conform from the Modifier List.
3. In the Conform Modifier Rollout, set the following values:
   • Method: Shrink Wrap
   • Pick Object: Select GeoSphere001 to add it to the Targets list.
   • As the geosphere moves, the cylinder's selected vertices (red in the following example) conform to the surface of Geosphere001.

     Tip: Turn on Wireframe Override in the Per-View Preference Viewport Label menu to better view this selection.

     
4. Click Pick Object again to exit pick mode.

Adjust the conformed vertices

Adding an additional Volume Select modifier can create a smoother transition as the geosphere moves through the cylinder.

1. Ensure Cylinder001 is selected.
2. In the Modify panel, select Vol. Select from the Modifier List.
3. In the Parameters rollout, set the following values:
   • Stack Selection Level: Vertex
   • Select By: Mesh Object; click the None button to select Geosphere001 in your scene.
   
4. In the Soft Selection rollout, set the following values:
   • Use Soft Selection: On
   • Falloff: 20.0
   Now, any vertices that are directly in contact with GeoSphere001 are fully selected, while the selection of vertices in the area surrounding GeoSphere001 gradually decreases.

   Tip: Turn on Wireframe Override in the Per-View Preference Viewport Label menu to better view the selection.

   

Add realism to the tube

Let's add a few additional modifiers to create a convincing animation that shows the geosphere fully enveloped in the cylinder.

1. Ensure Cylinder001 is selected.
2. In the Modify panel, select Push from the Modifier List.
3. In the Parameters rollout, set the following values:
   • Push Value: 1.0

     The Push modifier minimizes the interpenetration of Geosphere001 with Cylinder001.

4. In the Modify panel, select Shell from the Modifier List.
5. In the Parameters rollout, set the following values:
   • Outer Amount: 3.0

     This Shell modifier gives Cylinder001 some thickness.

6. Play the animation.
   Geosphere is fully enveloped by the cylinder.

   

Make additional changes

• Try adding a Relax modifier between the Push and Shell modifiers in the modifier stack.
  
  This step softens the movement of the geosphere in the cylinder, so vertices do not conform as tightly to the geosphere. In the following example, the Relax Value is set to 1.0 and Iterations is set to 30.

  Tip: Select the Push modifier and adjust the Push Amount if any interpenetration occurs.

  

Related topics

• Conform Modifier Rollout
• Conform Modifier Advanced Rollout