New PolygonSort node

[DolphinDream]

This new nodes allows to sort the polygons based on a distance to a given point or distance along a given direction. The Input is the verts/polys needed to be sorted and the reference (either a point P or a direction D). The node outputs the sorted polygons, same (input) vertices, centers of the sorted polygons, distances for the sorted polygons. The node has two modes P & D for distance to point and distance along a direction. Also there is an option to toggle the sorting ascending/descending. And yes, the node also has 3 presets X/Y/Z to preset the sorting direction to be one of the xyz axis.

• Code changes complete.
• Code documentation complete.
• Documentation for users complete (or not required, if user never sees these changes).
• Manual testing done.
• Unit-tests implemented.
• Ready for merge.

Example 1 : Sorting by distance to point P

Example 2 : Sorting by distance along distance D

[DolphinDream]

And a simple live demo..

[DolphinDream]

And a more intricate example / demo..

[nortikin]

what about area, other qualities? because we already have list sort with key user defined, for poligons can be added more specific options?

[DolphinDream]

what about area, other qualities? because we already have list sort with key user defined, for poligons can be added more specific options?

Sure thing. that can be done (area, normal angle etc). Btw @nortikin , can you show me an example of how you would sort the polygons by distance to point/direction using list sorting node?

[DolphinDream]

And another live demo :) the magic of toroidal fields
The nodetree takes the distance to polygons (output by the node) and feeds it to scale the polygons, in this case, inverse proportionally to the distance to the moving point.

Note: the reason why only the first 11 indices of the sorted polygons are shown is to avoid cluttering the demo.. as displaying hundreds of poly indices would make the illustration unreadable.

[DolphinDream]

Behold.. the sorting fiesta 🙌 .. now sorting also by area, normal angle to point and normal angle to direction.

[DolphinDream]

Anybody knows who created the area node ? I was wondering why the unit_normal is calculated via determinant instead of simply via crossproduct of the poly first edges + normalization. What’s the catch ? I notice the normals generated via both methods are the same, albeit the cross product should be faster.

[enzyme69]

I am totally intrigue by this and all the example demos...!

[DolphinDream]

I am totally intrigue by this and all the example demos...!

Thanks for the flowers, @enzyme69 :) It’s no mystery that the animation/scaling in these demos is doable with other nodes so not much credit can be given to PolygonSort node itself.. the less obvious from the demos however is that the polygons are in fact sorted and the text showing the reduced set of indices are the first 11 polygons in the sorted polygon list.

[DolphinDream]

Here’s another demo with sorting by “Normal Angle Point”. The red indices are the original (unsorted) polygon indices, the blue indices are the sorted indices. The numbers above the poly normals are the angles between the normals and the vectors connecting the centers to the moving point. (hence the sorting name)

[DolphinDream]

And sorted by area:

[DolphinDream]

If there are no objections.. this PR is ready to land.

[DolphinDream]

Final UI layout.

[zeffii]

@DolphinDream who?

This is one of the older nodes :) i don't see where it would handle (concave) ngons. I would do a rewrite. I'll port it over to sv4b280 immediately if you do.

[DolphinDream]

@zeffii The polygon sort node already does area calculation so it would really be replicated code to have it in two nodes. I was wondering if it’s worth factorizing the polygon related calculations into a polygon utilities file so that its functions can be used in multiple nodes. And the same could be said about edge related calculations.

[zeffii]

yes, factorize it out if you wish. (sverchok.utils.modules.polygon_utils.py) or wait till these nodes appear in sv4b28, no need to do it immediately.