Hi,

is it possible to make a “spiked” vertex/Point crease in a Subdivision?
If I use the crease tool on a Point, it seems that it is just an edge crease on all adjacent edges of the Point.

Did you check crease sample in the Houdini's Help !?

http://www.sidefx.com/docs/houdini10.0/nodes/sop/crease [sidefx.com]

I remember that there is a sample about using crease attr in the vertex points :?

I,ve checked all the example files, especially the “Attribute Create SOP”.
But it seems,that it has always the same effect as I described before, that if I am using crease on “points”,then the crease behaviour is still on edges corresponding to the Point and not to the Point itself. Perhaps I am doing something wrong, but even in the “crease surface node” the description is:
“Manually adds or removes a creaseweight attribute to/from polygon edges, for use with the Subdivide SOP”.
On the other side “CREASE” is a Local Parameter of a Vertex/Point, which
defines: “Point or vertex crease weight value”.
So I am a bit confused and I have really no idea. But thanks for help anyway

I'm not sure if any common subdivision algorithms actually make use of point creases. It sounds like an interesting idea, though. Is the result you're looking for a pointier point, but round around the point? I tried uniquing a single point on a cube into 3 points, then subdividing, but that basically just creased the 3 edges next to the point, instead of creasing just the one point. If you can work out the math for it, you'd probably have an interesting paper. :wink:

Edit: Okay, nevermind, “point creases” are called “corners” in subdivision. I found a description of them here [xrt.wikidot.com]. I don't know whether or not Houdini supports them already.

Hi ndickson,

this exactly what I mean, the “corner” tool described in your link makes Vertices spiky. I also didn't find a direct solution in houdini, but if you bevel a Vertex into a small Polygon you can use the “Edge Crease” to this Polygon (Polygons surrounding edges) and have a similar result like in the Picture of the discription. The only Problem is, that you have to change the outer geometry, which means for example that if you have (crease value = 0), the non creases result in the beveled case is different from the non creased result in the non beveled case. Perhaps there is another better solution, but probably you need access on the Catmull-Clark algorithm to do more.
But thanks for help so far. This is only a Little Thing and if this is not working on houdini nevermind but it would be nice if it did.