soft selection?

[frading]

Hi, I cannot find any sort of soft selection in houdini. I am looking for a way to apply an effect to a selection, and this effect being applied to each point or primitive depending on its weight, defined by "how much" it is selected.

I went to look for such a feature when trying to find the equivalent of a "cluster" in maya. It actually let you move/rotate a group of points after having assigned weights to them. I believe you can do something similar in houdini with the capture region and deform SOPs. I am still uneasy with them, but I believe that the capture region can only be moved at the object level, right? or can it be a the SOP level?

[brooklynj]

never mind sorry didn't fully read your question.

Are you talking specifically about effects ?Have you tried soft transform? It even has inherent interactive colors(soft radius) that correspond to weight.

[Mcronin]

Yes, using an Xform, or Soft Xform you can create the equivalent of a cluster. You can make the handle persistant, or add a Null in OBJ and channel reference it into the SoftTransform Sop.

Another thig you could try doing, and this is if you need a weight value per vertex to reference, is to use an AddAttribute SOP to add a custom float vertex attribute to a group of vertecies. You can then go into the spread sheet and set your weight values and reference them in an expression or whatever. The draback is there doesn't seem to be a way to paint a custom vertex attribute. You could of course use the capture weight attribute, but I thought I'd suggest this, since you may want to apply this effect on top of a character or something that's bound and weighted to a skeleton.

[edward]

Do you mean "point" as opposed to "vertex" attributes? The Paint SOP will happily paint "point" attributes fine.

[Mcronin]

Of course you're right Edward. I'm interested in this now, and I just did this:

Create a grid

Select points in the middle of the grid

group points

add floating point attribute to group using attribcreate

paint the group

In the Paint SOP's parameters enable "override color" and type the attribute name I want to paint into the field.

Seems to work pretty well. Is that the proper way to do it?

[edward]

Sounds right to me. You might be able to skip all that group stuff though since attributes must exist on all points.