I need to create something like this in 3D, i.e. a set of spheres connected with a straight line.

enter image description here

I know I can create each line individually, but is it possible to create a connector so that whenever I move one of the connected objects, the line adjusts itself accordingly (changes lenght, orientation)? Is there such an object or tool in Blender or Cinema 4D? If not, is there any way I can achieve this?

Thanks in advance, any help is much appreciated

  • 1
    Bianca, this is a highly technical question about constraints/behavior and it is specific to the 3D package of your choice. It would be best asked on a site devoted to those applications if you want a high quality answer. – JamesHoux Jul 15 '18 at 17:37
  • Thats what a mesh is. Although each edge must form a closed loop. but then you can duplocate the vertex. – joojaa Jul 15 '18 at 21:19
  • I have only some CAD experience and definitely nothing underhood knowledge. In a CAD program you can loft a small pipe between two circles. If you move those circles the pipe adapts assuming the structure isn't fixed. Maybe you can put those circles inside the spheres and group a sphere and a circle. Then moving a sphere forces the pipe to live along. I tried it and it worked. – user287001 Jul 15 '18 at 22:10
  • in most 3D DCC (Digital Content Creation) software packages, there are constraints... if you create your line (curve, polyline, small lofted pipe - your choice) and give it two locators, one at each end, and parent and constrain each end locator to the pivot locator of the relevant sphere, this should giver your desired result. – GerardFalla Jul 16 '18 at 16:13
  • I can think of a few ways to do this in Blender. Are you all right with the line continuing through and intersecting the spheres, or do you need to have one manifold mesh? – gandalf3 Jul 16 '18 at 21:30

In a polygonal 3D software like Blender or C4D, the core idea is quite simple, you just have to create some vertices and connect some of them. Then just move some around.

I.E. in Blender, from the start cube, enter edit mode, select all with A, merge at the center (AltM) to get a single vertex. Then use E to extude a vertex (and create an edge between), ShiftD to duplicate a vertex (without creating an edge), and use F to create an edge between two selected vertices.

In a few seconds, you can obtain that : enter image description here And if you move those vertices, the edge follows because they are defined by those vertices.
Note that I'm just displaying the editable mesh (with the vertex size display cranked up), it's not something renderable.

Now, if you want something more complex:

Get back to object mode, create some circles objects: enter image description here Apply their scale and location via CtrlA (needed for the hook to work well).

Now we will use some hook modifiers on the vertices object in order to make them follow the circles. First, let's enter edit mode, select some vertices you want to assign to a single circle and press CtrlG to assign them to a group. Repeat for each bunch of vertices for the other circles.

Now in object mode, go to the modifier tab and add a Hook modifier. Here's an example of a setup (with a little bit of animation):

enter image description here

Now from that, just a simple OpenGL render would do it. But for more advanced purposes, it's just the base to build from.


This can be achieved with the Tracer Object. Drop your spheres under the Tracer and change the Tracing Mode to Connect All Objects

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