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Is there any way to generate reversed taper geometry? In other words: I'd like to generate the geometry you can see in the following picture just by using displacement modifiers or by using nodes:

enter image description here

Q: Is something like this possible by using displacement? The purpose of me thinking that this is nearly impossible is because if having a larger displacement on top, how am I supposed to depict a tapering gradient bellow it visually on a map? You can not show a dim gradient bellow a bright surface on a displacement map right?

Note: This question is not specifically about cones, it is about any type of displacement where I have a bigger surface on top of a smaller surface.

For better illustration consider a plane , Subdivide it 100 times and switch to cycles rendered mode with Displacement type set to Displacement and bump. The if i create the following Node tree , i can get the following result. The node tree is finding the Length of the origin and using a color ramp to manipulate the falloff of the resulting spherical gradient and passing through a displacement map to get the final result , but how can i taper at the bottom and have a bigger surface at the top?

enter image description here

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    $\begingroup$ Maybe this will be nice to play with.. it's good for any surface of revolution, starting from a plane. In parrticular, it uses as its basis, your inverted cone. $\endgroup$ – Robin Betts Oct 15 '20 at 16:55
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    $\begingroup$ @RobinBetts i want a type of displacement from nodes $\endgroup$ – SHikha Mittal Oct 16 '20 at 9:52
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    $\begingroup$ @RobinBetts reopened, answer away $\endgroup$ – Duarte Farrajota Ramos Oct 16 '20 at 12:13
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    $\begingroup$ Have to confess, this one's driving me nuts. I can do it, but not make it simple. $\endgroup$ – Robin Betts Oct 19 '20 at 18:51
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    $\begingroup$ @SHikhaMittal, am not sure to understand well. Could you add some pictures indicating "starting from this, I want to have that"? $\endgroup$ – lemon Oct 21 '20 at 7:27
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I write an answer as proposed to by @SHikhaMittal. Though, still not sure this is the wanted result.

As this is about "any shape", have used an image, like a decal, to drive the displacement.

enter image description here

The shape is colored with "wireframe" node, so that we can see the result of the displacement in term of geometry.

The nodes:

enter image description here

Bottom part is the decal used to drive the displacement scale. It is 0 outside of the image.

The middle line is to offset the normal around the mesh center. X and Y parts are scaled and added to the normal in order to drive this normal "outside".

Top part, the wireframe colors.

Remarks:

We can notice that the scaled and displaced part looses resolution, because we only keep a small amount of vertices and scale them.

The other answer by Bruk, using another way to do it (scaling down a larger part along a cylinder) should avoid this issue.

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    $\begingroup$ Phew! Gordian knots are there to be cut! Indiana Jones draws his revolver... $\endgroup$ – Robin Betts Oct 23 '20 at 18:11
  • $\begingroup$ @RobinBetts, I can't beleive you have not find a way to do this kind of thing.(happy to see clutch is not mentioned anymore ; )) $\endgroup$ – lemon Oct 23 '20 at 18:16
  • $\begingroup$ @RobinBetts, btw, what is your favorite work by Matisse? (nothing related to the subject here) $\endgroup$ – lemon Oct 23 '20 at 18:29
  • $\begingroup$ (All IMO, and breaking BSE rules just this once) The whole body of work, really.. Matisse never had the preternatural facility of a Picasso, so I always felt he put the work in.. he didn't get lazy. (Picasso did churn out some junk, sometimes..) And he had great access to his own spirit. If there's one thing he can be accused of, it's being cosy. He said as much, himself. So just to be contrary, today, I'll choose the Piano Lesson. $\endgroup$ – Robin Betts Oct 23 '20 at 18:46
  • $\begingroup$ @RobinBetts, this one? fr.wikipedia.org/wiki/La_Le%C3%A7on_de_piano And surely we don't have to choose about Matisse or Picasso.. Just appreciate them. $\endgroup$ – lemon Oct 23 '20 at 18:49
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In case of tapers you can do it like this. enter image description here

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    $\begingroup$ Hi, @Bruk ..Wrong way up. :D.. the tip of the cone should be on the plane, requiring vector, rather than simple displacement, because of the undercut. $\endgroup$ – Robin Betts Oct 21 '20 at 14:24
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    $\begingroup$ @SHikhaMittal Hey man, don't be too hard on him :). I made the exact same answer and almost posted it. He's just trying to help :). $\endgroup$ – Jachym Michal Oct 21 '20 at 17:48
  • $\begingroup$ @JachymMichal ha , thats why i wrote "not being rude" , hey bro dont cry .......al BlenderERS are a family $\endgroup$ – SHikha Mittal Oct 22 '20 at 2:32
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    $\begingroup$ @SHikhaMittal Please also remember, that rep points does not mean skill or value (this is just and mostly participation result). $\endgroup$ – lemon Oct 22 '20 at 8:57
  • $\begingroup$ @lemon yeah sory $\endgroup$ – SHikha Mittal Oct 22 '20 at 9:39

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