Extract or isolate part of a surface

[atrev]

If I have a large model, whats the best way to me to extract a 3D volume out of it, with speed being the main factor needed?
The idea of it being that we need the point and surface data from a smaller region to examine it, but using the whole of the data will make it very slow.
If we can extract portions out of a mesh, we can then do analysis on the small patch instead of using the whole model, and we would also be able to cut just that patch using the cross section object to get the points required

Thanks

[nickz]

I just have posted http://www.dynoinsight.com/phpBB3/viewt ... f=2&t=2876 related to that.
We will also try to find time to expose specific extraction functionality in the next few days. So if it is not urgent, pls check this thread in a couple of days
Nick

[nickz]

We have posted the 4.3.3751 update where IMeshEx has two new methods: Extract() and Merge(). Extract() compiles all simplexes touching a sphere or a box to another mesh. Merge() adds all simplexes from one mesh to another.
The Cloud sample demonstrates usage of Extract. There is a new form opened on Tools > Extract menu option.
Nick

[atrev]

Works well. I'm just implementing into our our solution.

With the way it works it finds all simplexes that interset with the region? Using this function is there a way to cut it clean? such as a simplex sticking out of the region, split to give you just the part that is inside the region?

Thanks for help so far

[nickz]

Yes with some covenants. The algorithm is optimised for performance. It finds all vertices inside the specified region and adds all adjacent simplexes. In some cases there are simplexes which intersect the region only by its edge or by internal part with all vertices outside. Such are not included. For analysis it is not a problem as you normally extract with some margin and simplexes are expected to be small relative to the region.
Handling it exactly is possible too. We have some parameters for the implementation inside, but it would take some work to expose, test etc. And it would be little slower

With clipping it would be a different operation. It is useful too, but at the moment we are falling behind with the urgent v4.4 release. So it has to go later after the release. And there can be something else more urgent when we reconsider this

Regards
Nick