Create a volume (shell) from shapes

[ragohix769]

Simple (and dumb, sorry) question: I have a set of shapes created with draft, that creates a volume. I can measure surfaces with survey tool in Arch/BIM, that's ok.
Now I want to know the volume of that. So tried with a boolean fuse, nothing. Tried to create a shell from shapes, but maybe i've done that one time, but it was random. Created copy, simple copy, compound, then in Part make solid, but nothing. I imagine there is some simple mehod to create a solid volume from shapes, but what's that method?

[Roy_043]

You have a set of Draft_Wires in a compound. To create a solid from that you need at least two steps. Note that for some reason (I assume inaccuracies) the technique does not work for your model.

1. Create a shell from the faces with Part_Builder.
2. Create a solid from the shell, again with Part_Builder

The question I am left with is why don't you model this by extruding Facciata002 and Pianta002 and then performing a Boolean operation? It would be much more efficient.

[ragohix769]

You have a set of Draft_Wires in a compound. To create a solid from that you need at least two steps. Note that for some reason (I assume inaccuracies) the technique does not work for your model.

1. Create a shell from the faces with Part_Builder.
2. Create a solid from the shell, again with Part_Builder

I've done already this, but as you see without any success. So I think there is (as you noted correctly) some inaccuracies with some edges of the shell not coincidents that not closes the volume of the shell (I presume). Ok, that it's possible, but I have zero diagnostic or tool to find where is the problem and fix it, as I see. I think that is a problem beacuse If I have this kind of problems with a so simple shell, I can imagine what problem can be modelling complex things.

The question I am left with is why don't you model this by extruding Facciata002 and Pianta002 and then performing a Boolean operation? It would be much more efficient.

That is a good question, at the end I've done exactly that, using extrusion of the floorplan and cut with a shape/plane. Of course it not prone to this kind of errors, but I was trying to make an exercise to model creating only edges and then a shell from it, that with some complex things can be useful IMHO.

I've found too some bugs with create shape from planar edges, so at the end my workaround was to create a polyline with draft of the edges, then using draft_draf2sketch to this selection 2 times, to have a closed shape (rather then go to shape builder or making a draft_upgrade that does not work 99% of the times on creating shape from complex edges). Maybe I'll post this separetly

Thank you Roy

[ragohix769]

The question I am left with is why don't you model this by extruding Facciata002 and Pianta002 and then performing a Boolean operation? It would be much more efficient.

IYO what's the best boolean operation to cut this (the uploaded file at the end of this message) extruded solid of the floorplan whith the roof planar shape that I have merged?
I've tried to cut or intersect, but without success. Tried too with cut with plane, but I cannot understand the logic he says to me " You must select a face from the second object (cut plane), not the whole object", ok it's not a plane, but: can I make and easy boolean with these two entities?

You have a set of Draft_Wires in a compound. To create a solid from that you need at least two steps. Note that for some reason (I assume inaccuracies) the technique does not work for your model.

1. Create a shell from the faces with Part_Builder.
2. Create a solid from the shell, again with Part_Builder

The question I am left with is why don't you model this by extruding Facciata002 and Pianta002 and then performing a Boolean operation? It would be much more efficient.

Ok. It's there a method to create a shell->solid directlyin BIM/Draft/Arch without exit to Part_WB?

[paullee]

It seems there are several ways to do it, not sure if this is what you want.

I try a few ways, but seem Part Boolean Cut does not like coplanar face as usually suggested by other users here. And the original 2 sloping faces of your roof has a tiny gap in-between... I draw a line by snapping to end points on both faces result in a very short edge.

Check the revised model and see if it helps you

create_volume_from_shape_v002_r.FCStd

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[Roy_043]

he says to me " You must select a face from the second object (cut plane), not the whole object"

This means you should select a face in the 3D view and not select the object in the Tree view. The Arch_CutPlane command works fine for your model. Extrude Pianta002 to +4000mm and use Tetto002 and Tetto_004 to cut off the excess.

[ragohix769]

he says to me " You must select a face from the second object (cut plane), not the whole object"

This means you should select a face in the 3D view and not select the object in the Tree view. The Arch_CutPlane command works fine for your model. Extrude Pianta002 to +4000mm and use Tetto002 and Tetto_004 to cut off the excess.

I tried with the project here uploaded, cannot do that, he says to me always " You must select a face from the second object (cut plane), not the whole object". The second object it's already a face to me and I select it in the 3D view.

Code: Select all

OS: Ubuntu 20.04.4 LTS (KDE/plasma)
Word size of FreeCAD: 64-bit
Version: 0.20.
Build type: Release
Branch: unknown
Hash: bda12907dee4fe3f0e7dec8f7e09e098fc5036e4
Python 3.8.10, Qt 5.12.8, Coin 4.0.0, OCC 7.5.2
Locale: Italian/Italy (it_IT)
Installed mods: 
  * BIM

[Roy_043]

Seems to work fine here.

Code: Select all

OS: Windows 8.1 (6.3)
Word size of FreeCAD: 64-bit
Version: 0.20.27809 (Git)
Build type: Release
Python 3.8.12, Qt 5.12.9, Coin 4.0.0, OCC 7.5.3
Locale: Dutch/Netherlands (nl_NL)
Installed mods: 

[ragohix769]

Seems to work fine here.

Ok, finally I created the shell cutting it with https://wiki.freecadweb.org/Arch_CutPlane

Now I understand the logic behind cutting plane tool in Arch; IMHO it's a little bit tricky to understand because my problem was that the solid covered the face that has (mandatory) to be selected on 3D view. Maybe a possible selection in the tree view (for simple plane 2d shapes like this) should be enabled.

Really thank you Roy

[ragohix769]

Another question, maybe it's useful for others too: I've, as said, intersected a solid extrued (form the floorplan) with planes (the roof), so now I have all the shapes without any error or hole non connected. Ok.

But now to create a shell and then a solid (my objective it's simply to measure the volume of this house to make some energy diagnostic), It's there a quicker method rather then go to Part_WB, select all faces manually, make a Shell, and then make it a solid?

In general: if you an house modelled with bim, how to can find fast and easily the total volume of the construction modelled (exterior walls)?