The Spherify modifier distorts an object into a spherical shape. This modifier has only one parameter: a Percent spinner that deforms the object, as much as possible, into a spherical shape.
Modify panel > Modifier List > Object Space Modifiers > Spherify
Spherify shapes the dog inside the snake.
The success of the operation depends on the topology of the geometry to which it's applied. For example, a cylinder with no height segments will result in little change. Adding height segments will result in a barrel at 100 percent. Adding cap segments will produce a sphere.
Try this on a teapot.
Example: To use the spherify modifier to distort a teapot:
Click Create > Geometry > Standard Primitives > Teapot.
Create a teapot in the viewports.
On the Modify panel, choose Spherify from the Modifier List.
The teapot should now look like a sphere.
Adjust the Percent setting to less than 100%.
Example: To animate spherifying a teapot:
Modify panel > Modifier List, choose Spherify.
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(Play Animation).
Sets the percentage of spherical distortion to apply to an object.