# Geo Nodes v.3: how to twist and bend instances?

Hi there! I know how to use set curve tilt in GN for curves, but I would like to randomly twist instances generated later on, for a more organic look. Is this possible to do?

I assume it should be possible with set points and some good math skills, but that’s beyond my level…

Hi

Semantically, you can’t change the mesh of some “selected” instances w/o destroying the principle of instancing itself. The concept of instancing is re-using the same mesh/material data of an object multiple time.

But I can scale them for example. Isn’t there some way to enclose them in a deformer for example?

you’re scaling the object not the mesh, instancing is having different object sharing the same mesh, so you only change location/rotation/scale.

What i can recommend you to do is to have a couples of curve with different twisting and bending and then instance them

I see. I think I perhaps need to change the concept of the workflow for this too. I’m modelling a sunflower and until now, everything is made within one single Geo Node tree. But what I want from the leaves might be better to do separately by having a node tree applied to a bezier spline object, which I then draw manually in the 3D space (make few of them as a collection and then instance them for the arrangement?). Or make few of them within the original node tree and then figure out how to instance form a sort of collection?

Now, they all twist in the same direction and I think this will be obvious from many angles.

Thank you for any tips! I’ve been learning Geo Nodes since this week and the help here has been really appreciated

If you realize your instances, you can then modify each vertex individually.

If you now take the index of the vertex and divide it by the number of points in your instance, you can again access the instance this vertex originally belonged to, for example to generate a random value per instance:

Here, I used it to bend some strips randomly:

petal_variation_1_v01.blend (104.3 KB)

Edit: Twisting in addition to bending is also possible, but a bit more involved as you have to compute and individual twist axis for every petal. Here, I sampled the curve used for instancing again using the the computed instance index per petal

petal_variation_1_v02.blend (108.7 KB)

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Dear Lord, thank you! I will test this out!