[Feature Request] Twist part

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onekk
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Re: [Feature Request] Twist part

Post by onekk »

pathfinder wrote: Wed Oct 05, 2022 1:21 pm ...
But that's even more different and also probably pretty hard to realize.
Not counting that Blender has to calculate vertexes as is a mesh modeller and FC has to transform lines in curves (probably BSplines) calculating all the surface modifications.

I have seen some approach and is very heavy in term of calculations as example:

https://www3.cs.stonybrook.edu/~qin/cou ... mation.pdf

This is for mesh type as is used in computer graphics.


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Re: [Feature Request] Twist part

Post by pathfinder »

onekk wrote: Wed Oct 05, 2022 3:37 pm Not counting that Blender has to calculate vertexes as is a mesh modeller and FC has to transform lines in curves (probably BSplines) calculating all the surface modifications.
Indeed it would. I wouldn't expect it to work on any regular object created via Part or PD.

However, I wonder whether using a point cloud approach might work here, if the points are basically treated like the vertices of a mesh object in Blender are.
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Re: [Feature Request] Twist part

Post by onekk »

pathfinder wrote: Wed Oct 05, 2022 10:17 pm However, I wonder whether using a point cloud approach might work here, if the points are basically treated like the vertices of a mesh object in Blender are.
There are many techniques but almost all of them are relative to computer graphics and not CAD, in sense of Enginnering CAD, as such things are more related to CAE to see maybe deformations under forces but this something more near to FEM than to CAD.

A quick search will show you some results using the CGAL library.

IMHO this is more related to Computer Aided Design in sense of "Industrial Design" that is slightly different from the CAD of FreeCAD.

Indeed it will be a beutiful tool to have even in FreeCAD.

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Carlo D.
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Re: [Feature Request] Twist part

Post by NewJoker »

pathfinder wrote: Wed Oct 05, 2022 1:21 pm This is something different, because what you want to do is twist an already existing solid, while the functions discussed here create the twist while the object is being extruded.
That's right. Both tools would be very useful though.

onekk wrote: Thu Oct 06, 2022 5:23 am There are many techniques but almost all of them are relative to computer graphics and not CAD, in sense of Enginnering CAD, as such things are more related to CAE to see maybe deformations under forces but this something more near to FEM than to CAD.
Speaking about CAE, one could bend or twist (or otherwise deform) the existing model in the FEM workbench and then export the deformed mesh for further use: FEM FemMesh2Mesh.
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Re: [Feature Request] Twist part

Post by pathfinder »

onekk wrote: Thu Oct 06, 2022 5:23 am There are many techniques but almost all of them are relative to computer graphics and not CAD, in sense of Enginnering CAD, as such things are more related to CAE to see maybe deformations under forces but this something more near to FEM than to CAD.
This is very off-topic, but since we're here anyway, I'll just share this small observation I recently made:

If you look at current front grille designs of cars (e.g. Ford or Hyundai), you'll see that they are most likely designed using what is labelled as parametric design: They often consist of a lattice of repeating shapes that are deformed to the cars shape. It's a point where what may be considered more at home in the 3d modelling space and traditional CAD meet in real design.
I expect these worlds to merge more and more. I'm relatively familiar with current art production with a focus on sculpture, and I see more and more artists adapting more CAD-y approaches (Rhino3D is the big one, but I know of sculptures that have been built in Fusion).

I can understand that FreeCAD as a whole maybe needs to have priorities, or otherwise it may spread the resources it has too thinly and that a more artistic sculpting approach is maybe not in the interest of the majority. I'm just sharing my personal perspective.
NewJoker wrote: Thu Oct 06, 2022 8:36 am
pathfinder wrote: Wed Oct 05, 2022 1:21 pm This is something different, because what you want to do is twist an already existing solid, while the functions discussed here create the twist while the object is being extruded.
That's right. Both tools would be very useful though.
I agree.
NewJoker wrote: Thu Oct 06, 2022 8:36 am
onekk wrote: Thu Oct 06, 2022 5:23 am There are many techniques but almost all of them are relative to computer graphics and not CAD, in sense of Enginnering CAD, as such things are more related to CAE to see maybe deformations under forces but this something more near to FEM than to CAD.
Speaking about CAE, one could bend or twist (or otherwise deform) the existing model in the FEM workbench and then export the deformed mesh for further use: FEM FemMesh2Mesh.
Interesting; maybe I'll take a deeper look once I find the time.
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