Merging Geometry from Copy SOP

[John Pilgrim]

Hi all,

I'm trying to selectively reduce the point count of some curves, while maintaining the high point count near the corners.

I have used a Copy SOP to add spheres at the original corners, followed by a Group SOP to add the bounded points to a 'corner' group, followed by a Delete SOP to remove non-selected points.

The sizing of the curves changes.

When the radius of the spheres matches the curve, this whole procedure works fine. First image below.

MY PROBLEM occurs when the curve is smaller and the spheres overlap, resulting in points that should be in the 'corner' group being excluded from the group and thus incorrectly thinned out by the Delete SOP. Second image below.

So, a few questions...

(1.) How can I merge the spheres into a single unit, so that the the Group SOP has a single bounding geometry (rather than the current multiple spheres)?

A Merge SOP doesn't do this.

(2.) Is there a better way (maybe in a VOP SOP or CHOPNET?) to run through the main line points and test to see if each is within a given distance from one of the corner points, and to set an attribute if the test is true?

Thanks in advance!

John

The attached file is stripped down, but should give you the idea.

Edited September 27, 2012 by John Pilgrim

[hopbin9]

Oh this isn't how I'd approach the problem.

I'll give it a try and post an example. Assuming I succeed.

[hopbin9]

My idea was to calculate the dot product of connected neighbours in VOP and then use that to remove points.

See attached.

But I don't think this is what you were looking for.

corner-point-density.hipnc

[John Pilgrim]

Thank you Hop, that totally works!

Any thoughts on my Qns #1 and #2, so I can compare the different approaches?

John

EDIT: I wasn't initially seeing that it worked.

Edited August 30, 2012 by John Pilgrim

[hopbin9]

The curves always going to be 90 degrees?

[John Pilgrim]

The curves always going to be 90 degrees?

The originating poly curves will always have 90deg corners, which get rounded by the Convert SOP.

Conversion back to a polygon curve, as your example above did, is fine.

You can see the full project file here:

which is based (with permission) on another artist's work in another thread here on odforce.

Edited August 30, 2012 by John Pilgrim

[hopbin9]

Wouldn't it then be easier to cut the corners off and then merge new higher detailed ones back in to replace them. Since the corners are all the same shape, but just rotated.

Would something like that work for you?

[michael]

instead of spheres use metaballs - then convert them to poly...that way you'll get the merged shape for the bounding geo

hth

[hopbin9]

Have you tried using xRoundedCorner SOP tool from xTools?

Although looking at the asset I think it's using a global expression which I need to fix in the next release.

[harry_nicholas]

i'm not entirely sure what you want to do, but off the top of my (sop-based) head i would use a facet sop and flag "remove inline points" - it'll keep points in an arc and remove all points that are in straight lines.....