2D Area of Point Cloud

I have a 3D point cloud. I need to calculate the 2D area that is covered by the region. That is, if you projected my 3D point cloud onto the XZ-plane, what is the covered area accounting for all holes? You can convex hull a point cloud, but there are frequent concavities in my shape so this is no good.

Is there a simple way to solve this, either in .NET or with GH components? Images below for context.

Cheers,

Replies to This Discussion

Permalink Reply by Thomas Shouler on December 5, 2014 at 8:12am

And likewise -- I can get the outside boundary using metaball, but still unable to account for voids within the point cloud.

Permalink Reply by Daniel González Abalde on December 5, 2014 at 8:16am

Seguramente con componente de forma alfa u puede hacerlo

Or with mesh shadow comp.

Permalink Reply by Daniel González Abalde on December 5, 2014 at 8:31am

Permalink Reply by Rémy Maurcot on December 5, 2014 at 8:39am

Using this algorithm :

-project point on plane XY

-create mesh

-extract polyline on faces

-explode polyline and extract length

-sort length and extract end item

-dispatch polyline> max length

-region union

Attachments:

ContourPoints v2.gh, 72 KB

Permalink Reply by Thomas Shouler on December 5, 2014 at 8:49am

bingo -- thanks for the help all. certainly a few ways to skin this cat.

Permalink Reply by Rémy Maurcot on December 5, 2014 at 8:52am

You use what?

Permalink Reply by Thomas Shouler on December 5, 2014 at 8:55am

Permalink Reply by Rémy Maurcot on December 5, 2014 at 8:57am

You can adjust the max lenght parameter !

enjoy.

Permalink Reply by Rémy Maurcot on December 5, 2014 at 9:06am

Thomas,

In your image, How did you change the type of wires?

What it is the last component you are using?

Permalink Reply by Thomas Shouler on December 5, 2014 at 9:45am

You can edit defaults for the canvas styling in:

C:\Users\thomas.shouler\AppData\Roaming\Grasshopper\grasshopper_gui.xml

In this case, I have:

<item name="wire_default" type_name="gh_drawing_color" type_code="36">
<ARGB>150;220;220;220</ARGB>
</item>

<item name="wire_selected_b" type_name="gh_drawing_color" type_code="36">
<ARGB>50;0;0;0</ARGB> </item>

I also make the background a darker gray to make it easier on the eyes: