Scale from center

[io]

Hallo, old topic with no apparent easy solution, I ve seen Joreg’s grow module which works but does not seem to be do XY scaling.

Vector Maths - Scale from objects center

Hello VVVVers, I’ve got a question, which should be easy for most of you. Since I’m not good in maths, and I couldn’t find anything with the search-function, I need need your help. I’m tracking a blob with countours, and retrieving it’s contours. Them I’m resampling to have a few less points to deal with. Next I would want to uniformly move these points away from the blobs center. That’s the part I don’t know, how to do. If I just multiply the points by a factor, they get scaled away from the…

So, given some polygon (namely coming from the new Voronoi contrib), how can we scale them independently on XY from their center? Basically I d need to re-set the center of the objects.

Simone

[sunep]

Not completely sure I understood it right, but isn’t that what delauney gives you if you input the same numbers.

[io]

Not on Windows now, but the Voronoi contrib gives you the DX11 geometry, but all objects have as center 0,0. You can get the centroids so I am looking for a way to set the centroids as centers of the polygons.
Simone

[antokhio]

you need to get bounding box, but for that you gona need to pass it to compute
i think there is a bounds node in instance noodles you can check…
also if you receive mesh as bunch of subsets you have to do meshjoin in gsfx with instance id and then pass it as a raw buffer…
Doesn’t sounds like a hard job however bit tricky and use some advanced tech

there is BoundingBox (DX11.Geometry Get) you can try

[joreg]

@io i’m afraid i don’t get your problem from your description in the initial post. can you post an example patch that shows how Grow (2d) fails for you?

[io]

scale test.zip (2.9 MB)

[joreg]

indeed, there was a little spreading bugger for that module. i also added a Grow (2d NonUniform) that allows for individual scaling in X and Y.