Select and Delete Mesh Faces

Hi Guys,

Rhino is not so good at selecting mesh faces and i have to select each mesh face by clicking on each of them which is very time consuming.

Any idea how i could use GH to select a whole bunch of mesh face and delete them?

Maybe i could select them by angle (all the ones i want to delete are flat mesh face)

Thanks a lot,

Arthur

Replies to This Discussion

Permalink Reply by David Rutten on March 5, 2010 at 9:40am

I can solve this in 2 ways:

1) you draw curves on the mesh using PolylineOnMesh or SketchOnMesh or whatever, then you select them all and I figure out which faces those curves intersected and remove those from the mesh.

2) I add a Point object in the centre of every mesh face, then allow you to lasso a bunch of them, after which I go in and delete the faces with the selected points.

Option two is a bit more involved in terms of keeping track of data left and right. Option one has some more difficult mathematics to it, but it should be easy to use.

--
David Rutten
david@mcneel.com
Poprad, Slovakia

Permalink Reply by David Rutten on March 5, 2010 at 9:42am

It seems RhinoCommon has some functions that would allow me to track mouse movements. I think I'll start there, see if I can make it work.

--
David Rutten
david@mcneel.com
Poprad, Slovakia

Permalink Reply by Arthur Mamou-Mani on March 5, 2010 at 9:44am

The first one would be almost similar to clicking each mesh face since you need to draw a curve through each of them no?

The second one sounds very good.
It d be amazing if you can manage to do that!

Thanks a lot

Permalink Reply by David Rutten on March 5, 2010 at 10:09am

No, with the first one you could Sketch on the mesh. So basically you draw a curve on the mesh, then I figure out which mesh faces were 'implied' by the particular curve you drew.

The problem with the lasso approach is that it is not depth specific, i.e. it will select ALL points within the lasso region rather than just the visible ones. And you also have to draw a closed lasso region, whereas with the curve sketching you'd only need to draw a single, open spline across the mesh.

--
David Rutten
david@mcneel.com
Poprad, Slovakia

Permalink Reply by Arthur Mamou-Mani on March 5, 2010 at 10:30am

Both sound very useful in different ways:
Lasso tools for large area and curve selection tool for linear selection (river+road)...
Depth issue should not be a problem when dealing with topography because the mesh doesn't fold on itself (i could use both tools in plan).
thanks a lot

Permalink Reply by Matt Gaydon on March 5, 2010 at 10:44am

Hey Arthur,

Have you tryed downloading a trial version of Rhino Terrian as it has commands that you can tell the mesh where to break up for rivers, roads etc before you even mesh contours/point clouds whatever.

http://www.rhinoterrain.com/

Here's a link to a few tutorial i did for how to use it with different workflows though they maybe a little out dated now.

http://www.simplyrhino.co.uk/rhinotrainingvideos.html

Hope these Help

Matt

Permalink Reply by David Rutten on March 5, 2010 at 2:03pm

Update: new version, better interface.

You still need a very recent Rhino5 WIP for this to work, and it will most likely stop working when the next wip is released (I can fix it quickly, just bug me about it).

This version allows multiple passes over the mesh, and you can undo specific face deletions by pressing (and holding) ALT.

--
David Rutten
david@mcneel.com
Poprad, Slovakia

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