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["Sebastien Loriot (GeometryFactory)" <>]

Sorry, it is still not clear to me what you want to do.
I don't know if you want to compute the symmetric difference
or something else.

Sebastien.

On 11/02/2016 07:00 AM, Vahid Azizi wrote:
> Sorry, i tried to keep the message so short. anyway, I am doing
> following steps:
>
> 1) I have some points which they are supposed to be a polyhedron, It is
> the result by delaunry triangulation over these points: polyhedron
> <https://drive.google.com/file/d/0B6aDrBbewOPBUTlZaHlSYmsxWkE/view?usp=sharing>
>
> 2) i have another set of points which they are supposed to be a plane,
> after delanury triangulation over this set I have: plane
> <https://drive.google.com/file/d/0B6aDrBbewOPBSUlVdTdlUUl2XzQ/view?usp=sharing>
>
> 3) in last step i want to find the subsurface of the plane which is not
> in intersection with polyhedron. My idea here is to iterate over all
> triangles and keep all intersection points in a list, then i can create
> a convex hull out of intersection points. So, i have the subsurface
> which is in intersection with polyhedron. I did these steps for another
> purpose before and it works. I didn't try to extract the subsurface
> which is not in intersection but there must be a way for that.
>
> Now, the problem is with explained idea as you see in this image
> <https://drive.google.com/file/d/0B6aDrBbewOPBV2J2VktfUEFpN0U/view?usp=sharing>,
> intersection function doesn't return any intersection points for upper
> red triangle(upper part of the plane) . But there are two intersection
> points for down red triangle which are marked with blue star. As i spent
> some time for finding the reason it seems the problem is this triangle
> doesn't have any intersection with edges of triangles in polyhedron. I
> think if i could change the resolution of triangulation i could solve
> this problem. If i have more fined triangles in polyhedron with high
> probability there will be intersection with their edges. As i searched
> it seems there is not any option for modifying resolution of
> triangulation. Also the fig file for this issue is uploaded here
> <https://drive.google.com/file/d/0B6aDrBbewOPBR1RtVUE5ZkZVUE0/view?usp=sharing>,
> maybe it could give you better view.
>
> My questions are:
>
> Is there any better way to find the subsurface of the plane which is not
> in intersection with polyhedron? Here just assume i have to two 3D
> polyhedrons which i want to find the part which doesn't have intersection.
>
> if there is not any better way, how could i solve the current issue?
>
> Thanks in advance,
> Best,
>
>
>
> On Tue, Nov 1, 2016 at 3:36 AM, Sebastien Loriot (GeometryFactory)
> <
>  
> <mailto:>>
>  wrote:
>
>     It is not clear (at least to me) what you are trying to do.
>     What are you looking for? An intersection function for 2 triangle soups?
>     A 3D constrained triangulation?
>
>     Sebastien.
>
>     On 11/01/2016 03:40 AM, Vahid Azizi wrote:
>
>         Hi all,
>
>         I have a geometry volume and a plane(their vertices), the Delaunry
>         triangulation is applied on both of them(their vertices). For the
>         geometry volume i get 16 facets and for the plane i get two
>         facets. I
>         need to find intersection between these two. It seems in some
>         case the
>         plane which is inside the volume doesn't have intersection with any
>         facets of volume. I searched for changing resolution of
>         triangulation
>         but it seems there is not such a option. I've attached an image
>         which
>         depicts the situation and also a fig file which you can rotate
>         the image
>         to see what is the problem. The blue stars are intersection
>         points for
>         down red triangle.
>
>         images:
>         
> https://drive.google.com/drive/folders/0B6aDrBbewOPBR2gwTE5JZm4yNnc?usp=sharing
>         
> <https://drive.google.com/drive/folders/0B6aDrBbewOPBR2gwTE5JZm4yNnc?usp=sharing>
>
>         Is there anything that i can do, maybe with resolution or with
>         intersection or do i need to go with another approach?
>
>         Thanks in advance!
>
>         Best,
>         --
>         /Vahid/
>
>
>
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> --
> /Vahid/