Manipulating Pivot Point of polygons with ICE

[TheDutchOracle]

hi there,
I'm trying to recreate the following plugin in ICE:https://vimeo.com/36915151

but i was specifically wondering best ways to control (manipulate) the pivot point position of polygons with ice (center/ancher point).

i always need the pivot point to be on the edge (dynamically) without preparation of an imported model.
Anybody ever managed to do something like that?

PS - I did already see a great video by Chris Marchall's about this on Vimeo: https://vimeo.com/31421343
but that was including polygon preparation (manually moving pivot point) + i did not manage to go around corners with it yet.

Moderator edit: the point of the following "Newcomer alert" is
that you start actually using the URL tags, so here goes:
Newcomer (<20 posts) alert: please use the URL tags - HB

[xsisupport]

If I understand correctly (I didn't watch any of the videos), then...

If you're moving polygons with ICE, you have to do it by moving the polygon points.
So you would be rotating those points relative to some pivot point that you yourself calculate.

[TheDutchOracle]

yes,

So let´s say i have 1 cube.

Normally the pointposition of every polygon is in the center of that polygon.
but in order to flip all polygons ´dynamically' i first need to find a way to move the pivot point (or rotation point) from the centre to an edge of that polygon. (not manually but with ice)

[TheDutchOracle]

By the way Stephen
I think a.t.m. your arnold site link is not working.

maybe it should be : http://arnoldsupport.com/ (that one works)
you typed (in your signature link): http://arnoldsupportcorner.com/ (giving me a 404 page)

[xsisupport]

yes,

So let´s say i have 1 cube.

Normally the pointposition of every polygon is in the center of that polygon.
but in order to flip all polygons ´dynamically' i first need to find a way to move the pivot point (or rotation point) from the centre to an edge of that polygon. (not manually but with ice)

Any rotation of a polygon would require you to to either rotate the object itself, or rotate the point positions of the polygon vertices.
In terms of rotating a point, you can rotate it about anything you want. You just need to figure out the axis of rotation based on your desired "pivot point".
There's no actual polygon pivot point that you can access or move.

Thanks for the heads up on my sig.

[Chris_TC]

yes,

So let´s say i have 1 cube.

Normally the pointposition of every polygon is in the center of that polygon.
but in order to flip all polygons ´dynamically' i first need to find a way to move the pivot point (or rotation point) from the centre to an edge of that polygon. (not manually but with ice)

As Steve already explained, every deformation you do in ICE is point based. While there is an ICE attribute called PolygonPosition, it's really just the average position of the polygon's points. You can't change this attribute, and even if you could, it wouldn't help with what you're trying to do.

I've put together a quick compound, see attachment.
The main nuisance with building these kinds of effects is having to convert between the contexts. Most of my ICE compound deals with tackling these issues. I've had to use many, many "Build Array from set" and "Select in Array" just to convert between edge, polygon and vertex contexts.

I feel that ICE should allow us to directly work with polygons or edges, just like in regular modeling. That way we wouldn't have to do all the conversions into per-point ourselves.

[TheDutchOracle]

Wow!

there are many things in there i was just trying to understand.
Thanks for sharing this and for the effort.

[angelous4x]

very cool share.
resource dump thread would be a great place for this.