Volume between meshes

Replies to This Discussion

Permalink Reply by Hyungsoo Kim on August 5, 2016 at 11:35am

Hi.

I'm not sure whether this method is gonna help or not. Anyway, check attached if you want.

You'll need "Weaverbird" plug-in for mesh join & welding.

Attachments:

• Toposurfacenytterrn_re.gh, 40 KB

Permalink Reply by Joseph Oster on August 5, 2016 at 12:53pm

I converted the mesh to a brep by converting and joining all the faces, then projected the perimeter to 'WorldXY' and created a 3D volume.  Quick and simple.

Then I spent WAY MORE TIME making a movable box to explore volume differences...  Took at least three tries and way too much time for a simple thing!

No plugns or Rhino file required (your mesh and curves are internalized).

P.S.  I found one invalid surface out of 818 triangles on the mesh so ignored that one.

Attachments:

• Toposurfacenytterrn_2016Aug5a.gh, 50 KB

Permalink Reply by Joseph Oster on August 5, 2016 at 3:04pm

Here is a more robust version of 'Mesh to Brep'.  It ignores mesh faces that don't have three 'Disc (Discontinuity)' points, i.e., they are not triangles.  In this case, there are two faces that consist of just a line instead of a triangle, so they are ignored by 'Dispatch':

Attachments:

• Toposurfacenytterrn_2016Aug5b.gh, 56 KB

Permalink Reply by Hyungsoo Kim on August 6, 2016 at 3:51am

Just in case your mesh is the topo of your excavation site and there is a desired digging area.

(With only native GH components)

Attachments:

• Toposurfacenytterrn_reV2.gh, 41 KB

Permalink Reply by Joseph Oster on August 6, 2016 at 6:52am

Not "only native GH components"...  This code depends on 'MeshEdit Components (Mesh Volume)'.

Do you see a problem with the approach I used, converting the mesh to a brep?  From there, it's quite simple to use 'SInt' to get the excavated volume or 'SDiff' to show the hole in the surface.

Permalink Reply by Hyungsoo Kim on August 6, 2016 at 7:01am

Ok. my bad. This is truly native.

And do you mean every time he should convert mesh that have whatever count of faces to nurbs ?

Permalink Reply by Hyungsoo Kim on August 6, 2016 at 7:04am

File

Attachments:

• Toposurfacenytterrn_reV3.gh, 41 KB

Permalink Reply by Joseph Oster on August 6, 2016 at 7:18am

Did you look at my code?  Seems to work fast and fine for me.

I don't really understand your latest code yet...?  Looks like you are re-building the mesh for some reason?

I don't see anything that affects the depth of the building site?  When I move the 'Building FootPrint' up or down, the excavated volume doesn't change?

Permalink Reply by Hyungsoo Kim on August 6, 2016 at 7:45am

Building footprint curve is just for projection. Use "Excavation Level " slider.

Permalink Reply by Joseph Oster on August 6, 2016 at 3:18pm

Well, this was amusing...  I decided to build a road, carving out terrain or building it up as needed.

• In 'Top View', draw a curve for the road on the 'WorldXY' plane. Make sure it starts and ends outside the bounds of the mesh surface.
• Adjust the 'Count' slider to have as few points as possible but as many as necessary to follow the road accurately.
• The 'raise path' slider will raise the projected points above the mesh surface, which can be helpful in reaching a "state of equilibrium" where the volume filled in is nearly the same as the volume of material excavated.

The two 'Volume' components are VERY SLOW - ~45 seconds on my laptop - and should probably be disabled while messing with other parameters.  Sometimes a 'Volume' component will fail but a slight adjustment of a parameter will "fix" the problem.

Green in the image below shows "build up" or fill volume.

Attachments:

• Toposurfacenytterrn_2016Aug6b.gh, 72 KB