I'm new to Blender and want to morph a sphere (or cube, cone, cylinder) into a torus.

Thanks for any help.

  • 9
    $\begingroup$ Sphere (or cube, cone, cylinder) and a torus are not homeomorphic to each other, so it is not pretty Straightforward as it may sound. Could you add more information about how what's the strategy you intend to use to handle the difference in the topology? Exactly, when and how you imagine the hole being generated? Do you have any reference example? $\endgroup$ – Carlo Apr 23 '17 at 23:30
  • $\begingroup$ I do not have any references, which is why I'm asking. I have seen it done with particles, but not with shape keying. $\endgroup$ – user258959 Apr 24 '17 at 0:25
  • $\begingroup$ you could perhaps fake that morph in some way, eg using a sphere and a torus, using shape-keys on both to make the first shape become an intermediate shape visually very similar to another shape obtainable with shape-keys also by the torus.... and then animating the transition. $\endgroup$ – m.ardito Apr 24 '17 at 8:22
  • $\begingroup$ So you are specifically asking a solution that use shape keys? This should be totally feasible by translating and collapsing the vertices in the target position with the help of many tools. But the results will easily reveal that the sphere (or cube..) was made out of a torus with the inner veritices collapsed. Would something like this satisfy your need? Could you add more information to your question? $\endgroup$ – Carlo Apr 24 '17 at 17:50
  • $\begingroup$ Thanks all for your help and suggestions. As long as a 3d shape morphs into a torus without particle system, it's ok by me. @Carlo, that animation totally helps. Could you show me how that was made? As I mentions, I'm knew, so a step by step animation like that or explanation would be greatly appreciated. Thanks a lot. $\endgroup$ – user258959 Apr 24 '17 at 19:35

Modeling & shape keys

You can somehow fake the effect with shape keys.

It's just a matter of grouping vertex in the target position. The way about how to approach a similar problem could be various, and they really depends on the shapes.

Start by creating two shapkeys and enter edit mode to start changing the vertices position:

enter image description here

If we for example consider the morphing from a sphere, you could start by selecting the inner faces of the thorus and then scaling everything toward the center and then on the Z axis:

enter image description here

Invert the selection and start running alternatively the command "smooth vertex" and "to sphere". The purpose would be to better distribute the edge loops to mime a UV sphere topology (at least outside). Then scale the whole selection to match with the lower and upper vertex.

enter image description here


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  • $\begingroup$ Despite having all those vertices on the inside of the sphere from the inner circle of the torus draining system resources, this is probably the best way to do this. $\endgroup$ – RobotUnderscore Apr 27 '17 at 0:45

An approach using screw modifier and shape keys:

enter image description here

For instance, for the sphere:

  • Create a circle
  • Shift it in edit mode from its origin
  • Add a screw modifier and a subdivision surface

enter image description here

  • Now add/create a shape key
  • Scale and place its geometry to the center
  • Scale the overlapping part along the screw axis

enter image description here

  • $\begingroup$ Clever approach to reduce the number of operation needed for all the solids of revolution $\endgroup$ – Carlo Apr 27 '17 at 19:58

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