Re: Cutting a polygon mesh with a curve?

["Ahmidou Lyazidi" <ahmidou.xsi(at)gmail.com>]

Open SI3D>effect>MergeGeometry if I remember well....sorry I couldn't resist :)

2007/3/2, Bradley Gabe <withanar(at)stanwinston.com >:

That's a neat idea Joey! I've used curve snapping for similar things in
the past, just didn't think to try it while in add edge mode.

I'm not sure if it's my system, the fact I'm on linux (GUI and sticky
keys lag), or that this mesh is really heavy, but I don't think I have
the patience to cut that many edges, one-by-one.

Incidentally, the technique you are describing is the exact effect I'm
trying to reproduce through a script or plugin. I don't need any of the
intermittent data from the curve between existing edges, only a vertex
at each point where the curve intersects.


> Brad,
>     You may already be aware of this, but if your mesh is not too heavy
> it may be possible to hand draw your edge splits. If you work from your
> top window from example, and draw your spline through the mesh you want
> to cut, turn on  curve snapping,  select the mesh, and split your polys
> with the Add edge tool, the add edge tool will snap to the curve while
> adhering to the selected mesh's volume. In other word's it will snap to
> the curve profile say in the top window, but will draw the new edges in
> the poly plane of the mesh. With a little effort you can add detail to
> the mesh using a curve as a guide. Doesn't look to be scriptable because
> it appears to rely on the current view for the snap positioning, but
> might be enough to get what you need. What is really neat is that it
> will snap to edges where the curve intersects with the poly edge as well
> as snap to the poly plane so you can create new poly shapes within an
> existing polys plane using the curve as a guide.
>
> Joey Ponthieux
> NCI Information Systems Inc.
> NASA Langley research Center
> ____________________________________________________________
> Opinions stated here-in are strictly those of the author and
> do not represent the opinions of NASA or any other party.
>
>
>
> Bradley Gabe wrote:
> > I attempted the various modify>booleans first, and it tends to slice my
> > object in undesirable ways. It works for only a subset of projected
> > curves. I'd also prefer to not have to Frankenstein split meshes back
> > together repeatedly, since there's a risk of mucking up the integrity of
> > pre-existing texture maps and such.
> >
> > I'm not the greatest topology guy, but I might be able to write a custom
> > tool to do this:
> >
> > 1-Use point locators to find the nearest point on every edge that the
> > curve projection intersects
> > 2-Create a point at each of these locations
> > 3-Connect the dots
> >
> > I'm not sure I can get steps 1 and 3 to work. :-)
> > I just wanted to make sure I wasn't re-inventing the wheel for this.
> >
> > -Brad
> >
> >
> >
> >> *blinks*
> >>
> >> extrude curve then bolean results, same as what trim *kinda* does
> >>
> >>
> >> On Thu, March 1, 2007 6:40 pm, Bradley Gabe wrote:
> >>
> >>> Is there a way to cut edges in a polygon mesh using a projected curve or
> >>> surface intersection? Some analog to a nurbs trim?
> >>>
> >>>
> >>>
> >>>
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