[cgma-dev] Facet/Cholla engine

[Jane Hu]

Yes, I've just done this in revision 6116. Thanks for the reminder!

Jane


On Wed, Jan 22, 2014 at 8:26 AM, David Thompson
<david.thompson at kitware.com>wrote:

> Hi Jane,
>
> > I tried both of your programs, you are right that the key for success in
> build_facet_surface relies on the how the CubitPoints are defined. I have
> observed the following:
>
> Thanks for the confirmation. It would be great if your observations and/or
> the documentation string in my earlier message could be put in the
> build_facet_surface() documentation of geom/facet/FacetModifyEngine.hpp so
> that people don't have to search the mailing list to find out how to use
> the engine. Should I try to merge your observations into the documentation
> below?
>
>         Thanks,
>         David
>
> >
> > 1. If you define new CubitPoints for each facet, even they share the
> same location, the code is creating separate surface for each facet.
> >
> > 2. It doens't matter if you provide the point list or not as long as the
> facets are created through different sets of points. I attach another file
> here to demonstrate, where you can see, if you define 4 facets using 12
> different points (just pointer different), even you don't provide the point
> list, the code still generates 4 surfaces(which is prefered). When building
> a body, the duplicate vertices and edges are merged, leaving 4 refedges and
> 4 refpoints in the model.
> >
> > 3. If you define facets using shared points, you indicates to connect
> the edges and don't separate the model on the points. In this case, you
> have to give all such facets in one build_facet_surface call, otherwise,
> code crashes on not being able to find the shared edges.
> >
> > I'll put the feature-angle issue as an enhancement bug to the system.
> >
> > Thanks and have a nice day!
> >
> > Jane
> >
> >
> >
> >
> > On Sat, Jan 18, 2014 at 3:08 PM, David Thompson <
> david.thompson at kitware.com> wrote:
> > Hi Jane,
> >
> > I've found a combination of things that allow me to build models with
> multiple faceted surfaces per shell. It boils down to creating disjoint
> sets of CubitPointData instances for each FacetSurface, but which re-use a
> given CubitPoint shared among facets on the same FacetSurface. When
> multiple FacetSurfaces are combined into a shell, the facet engine merges
> the duplicate vertices on their common boundaries. I tried passing an empty
> point_list, but that failed. Passing CubitFacetData instances to the same
> build_facet_surface() call that have coincident points encoded in multiple
> CubitPointData instances (instead of a shared instance) also fails.
> Attached are working examples (one build 4 FacetSurfaces from 4 triangles,
> the other 2 FacetSurfaces from 4 triangles).
> >
> > It would be nice if the documentation for build_facet_surface() was
> updated to include some mention of this:
> >
> >     //- Create one or more new FacetSurfaces with all of its lower
> >     //- order entities.  Use an optional feature_angle to break
> >     //- surface.
> >     //-
> >     //- Where the input CubitFacet and/or CubitQuadFacet instances
> >     //- share a vertex, they should reference the same CubitPoint
> >     //- pointer. However, no CubitPoint instance shared with a
> >     //- surface created by a separate call to build_facet_surface()
> >     //- should be referenced; if multiple build_facet_surface() calls
> >     //- are made, points on shared boundaries between will be merged
> >     //- when the a shell containing the surfaces is created.
> >     //-
> >     //- The point_list should contain exactly the points in
> >     //- the input facets and no others.
> >
> > I still have not been able to get surface-splitting by feature_angle
> working, so that is probably still worth a bug report.
> >
> >         David
> >
> >
> >
> >
> > --
> > Jane Hu
> >
> > Asst. Researcher
> > Dept. of Engineering Physics
> > UW @ Madison
> >
> > "And we know that for those who love God, that is, for those who are
> called according to his purpose, all things are working together for good."
> (Romans 8:28)
> > <multifaceted-works.cxx>
>
>


-- 
Jane Hu

Asst. Researcher
Dept. of Engineering Physics
UW @ Madison

"And we know that for those who love God, that is, for those who are called
according to his purpose, all things are working together for good."
(Romans 8:28)
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