Volume not showing, but Solid Inspector says all is good?


#1

Solid inspector2 says

Everything is Shiny, but the volume is not showing in entity info for the group ?

335 dune.skp (182.7 KB)

Any ideas ?


#2

It looks like the reason SketchUp doesn’t recognize the group as solid is due to an edge on each side that is shared by 3 faces.

Make an adjustment there so that area would be printable and the group will show as solid and you’ll get a volume.

I pulled those small horizontal faces up 1/4 in. and erased some internal edges.


#3

Oddly it does report as OK, but it’s NOT a Solid because your have some edges supporting more than 2 faces - the strict requirement for a ‘solid’ - see the screen shot with Xray…


A minor adjustment of the form should avoid this issue and make it solid…


#4

Dave and Tig,
TY ! I did not know about the edge and 3 face issue…
Is there a tool to help identify this in more complicated drawings ?


#5

I would refer to that as SketchUp’s requirement, not the requirement. As long as all edges bind an even number of faces, whether it’s 0, 2, 4 etc, there is a defined volume inside of the mesh. Too bad SketchUp doesn’t acknowledge it.


#6

But in the model in question, there are three faces.

@hersratings, You might try TIG’s Solid Solver but there will always be cases where it takes human eyeballs on it.


#7

It is 4 faces, two horizontal and two vertical.


#8

I don’t really want to argue with you @eneroth3, but the areas that both @DaveR and @TIG have referenced only have two vertical faces and one horizontal face all coming from a single edge.
I remember this particular layout being somewhat problematic when Thomthom first released the extension.


#9

If you select all the geometry and run this snippet it reports there are edges with 2 and 4 faces.

Sketchup.active_model.selection.grep(Sketchup::Edge).map { |e| e.faces.count }.uniq

You can also see with a section cut how one of the mention areas actually only have “conventionally” solid edges binding 2 faces, and the other has a central edge binding 4 faces.


#10

Julia, I don’t know of any software that will ‘acknowledge’ two conjoined cubes in a single grouping, as a single solid…

if they are two groups that happen to have an edge in exactly the same position, then many see that as solid…

however, even that is a relatively new concept in slicer software…

john


#11

Two cubes that meet in an edge have a defined inner volume. I don’t know how you define “a single solid” though. Would two separate cubes in the same group be a single solid?


#12

Huh?
Box, I would say that there are four faces coming from that single edge.
Basically SketchUp doesn’t handle all solids (although simple to understand in real life) as should. See the example in next image (a block with a hole pushed through):


The left solid block shows no volume, the right one does. But both would clearly be solid in real life.
The left one was created by moving the green edge to merge with the one on top (red, not visible yet), with now four faces attached to the red edge.
SketchUp needs some improvement on this point.

p.s. in the original uploaded model select the questioned edge (equal to mine in red) > right click to get its context menu > Select > Connected Faces. Entity Info goes from one entity to five, which is one edge and four faces.


#13

in 3d software Manifold [often called ‘Solid’] essentially means “Manufacturable”…

what possible manufacturing/construction technique can create the zero depth join?

either you have a thickness or a gap [ even if microscopically small ]…

without a material bridge at your intersection of four faces, the object will be prone to failure…

it not just SU that expects only two faces per edge…

john


#14

I see that as technical language getting in the way of modellers who are not manufacturers.

For the purposes of SketchUp modelling, the object with the zero depth edge is a solid logically.

Besides, manufacturing is changing, and this object could be printed now.


#15

John, I see your point and I even thing we have discussed this very issue in the past. But let me ask you, can manifacturing/construction technique create faces that are as flat and smooth as software can? I’m not talking about thickness but mean all possible vetices on the face on one and the same plane? The answer is no. But still we use these faces. The only obstacle I see is for software to get it programmed.


#16

‘solids’ were added to SU for 3d printer output, and at the time even overlapping independent ‘solids’ were not recognised by many ‘slicer’ softwares…

at least that has improved and untidy unions aren’t even required by many these days…

if SU had decided to go against convention and allow more than two faces, I doubt anyone would be using SU for 3d printing today…

current slicer software that accepts these ‘junctions’, actually repairs them, adding thickness with an additional offset edge, but is it where you want it…

by ‘failing’ the item, SU allows you to remodel adding thickness where you want…

john


#17

Understood.

My point is about pure modelling vs translating that model into a manufacturable item.

In any 3D modelling space - logic dictates that the object in question is a cohesive volume - call it a U shape. Not everyone who models that object is considering how or if it can be manufactured or cares - so in general, logical understanding in the SU modelling space is seeing objects as simple geometry / volumes.

When required, translate away into the appropriate manufacturable shape for your specific use case.


#18

ok, this I can understand; to get things printed.
I just added 0.1mm just to get the volume. Not printable yet I guess


#19

0.1 mm should be fine for titanium…

0.001 mm for dental ceramics…

if you can afford it…

john


#20

:moneybag: sorry, empty.