Please help with geometry nodes and set position

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1

Hi,

Please, I need some help with this. I’m trying to morph my mesh using geometry nodes and set position. However I want to achieve this on top of a deformed mesh. I am trying to take the normals into account, however the set position doesn’t fully align with the blendshape I’m trying to morph to. Here is a blend:
postSculpt_001.blend (1.3 MB)
Please if someone can tell me how the math behind it is done right, I would highly appreciate it.

Thanks,
Stefan

2

Alright, I give up on here. Seems like a problem impossible to solve

3

What are you trying to achieve? It is not really obvious from your description…

4

Thanks so much for your reply. I’m trying to add blendshapes on an already deformed mesh. Especially an imported alembic. Since the alembic overrides vertex position, I will have to add shapes after alembic modifier. My problem is now, that I don’t know how to “attach” the blendshape deformation to the object normals correctly.

5

I believe you need to transfer the indices position. One criteria is that both shapes have the same amount of indices.

Tutorial

6

hey, yeah, both objects have the same indices. In the blend file I attached there is a simple expample of the issue. I do get my deformation as such, however when I try to convert it to tangent space, the deformation is off. I simply don’t know enough about vector math, also geometry nodes is a very new area to me

7

Hm, i tried again all day today but just can’t manage to convert the deformation to tangent space. Where else could i ask for some help ?

8

Yessss i finally managed. Can do now Sculpt on top of alembic. Next step is to make it an addon and automate repetitive tasks

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