On 7/26/2025 10:46 PM, ingo wrote:
> Josh,
> 
> for mesh and bicubic patches deformations of pre-made models is hard. One can
> use scripts to extract .obj files in to mesh.
> 
> When one creates mesh and patches, things are easier. You can "just" remodel the
> object with different parameters. Think extruding, lofting, sor or even
> parametrics. Very old code below for patch modelling and clock guided
> deformation.
> 
> The use of deformation grids (cubes) in 3d works. Sorry, my experiments for that
> are lost. It is basically not so different from "boning", you have to virtually
> "attach" vertices to the cubes in a grid. In similar vain you can use a single
> spline to deform a mesh. But, it all has to be done to arrays. That's why I
> build arrays first and the mesh from that in the meshmaker macros. When you
> adapt the array building system you can add springiness, like in cloth
> generation systems to get gel like objects that deform.

My modeling system does this with a Modeling array and it then creates 
the array of Control points needed to create the array of bicubic 
patches I want.

I found Nathan Reed's page, quoting Inigo Quilez' 
https://iquilezles.org/articles/ibilinear/, on the same bilinear 
interpolation I've been doing on my modeling grids. What I hadn't been 
doing was all the algebra that allows for hopefully a faster calculation.

My bicubic modeling system can handle sheets and cylinders and box-like 
shapes, but so far I don't have an easy way to combine models into one 
modeling array that would allow for sharp corners. I have a few ideas 
brewing, but only sketches of how I could do it. I suspect for each 
element of a building I want to have I'll need to create a macro to 
generate the section, and then deform the control grid as needed. I'm 
still noodling on it.

Josh

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