Can't calculate volume of 3D structure

advice

#1

First time using SketchUp (Make) and it’s quite useful. Thanks for making the program accessible to all!

I made a 3D structure, and I’m trying to calculate the volume that is contained within the structure. I have the entity window open, and when I make a simple object, yes, it’ll calculate the volume, but with this larger complex structure, no such luck. I’m just interested in the net volume. I’ve spent about 2 hours looking for any “leaks” in the structure, but haven’t found any. I also deleted all the inner structures that I used to build up the overall structure, hoping that would fix the problem, but, again, no luck.
3D Volume Trial2.skp (221.6 KB)

Any ideas as to why it’s not calculating the volume? I’ve attached the file here, so others can see what I’m trying to do…


#2

The reason is that it wasn’t a closed volume. It has a number of other problems, too, including coplanar faces and reversed faces.

After correcting the mess and making it a solid component, SketchUp reports a volume with no problem.

.


#3

The fastest way to fix it might be to create a component from everything and then use ThomThom’s Solid Inspector. It was able to repair all the issues (mainly reversed faces).


#4

Coplanar faces and reversed faces- I’m guessing those were the ones that had different shading?

Thanks for the help, and I’ll be sure to check out ThomThom’s Solid Inspector!


#5

The reversed faces are the ones with the blue shading. Coplanar faces are ones that are in the same plane and in this case are overlapping.

Small holes can create problems, too. Aim for creating solid components or groups and you’ll by default have better models.


#6

I hope I’m not asking too much of y’all, but I was wondering if you’d have any suggestions/ideas for quickly measuring volumes when I have data on the dimension of a structure in three planes. (I’m using SketchUp for research on biological structures, not to build or design stuff).

I created an image of the data in three axes (attached) and was wondering if there’s some way to calculate the volume. Its the same one as the previous, only this one I didn’t fill in the bits along the way with all the extra lines. Just the raw data here (I assume the base is a circle, and that’s pretty realistic).

I was thinking it would be straightforward if there was a way to have the push/pull tool pull up the base quarters of the circle along the curved lines, but I haven’t seen a tool like that. Other ideas of how y’all might do it? I can assume the structure is a circle as one goes up, which is why I made the arcs along the vertical lines.

Thanks in advance for any advice, and if this seems like too tricky of a problem, I’m fine to go on estimating the structure as a half ellipse!

Cheers,
Michael


#7

To clarify further: Every face in SketchUp is like a piece of paper. It has two sides, a “front” and a “back”. The default material in SketchUp colors the front side white and the back side bluish-gray (depending on orientation to the camera, shading can make it hard to tell these apart, so many of us alter the default material to have a more distinctive back color). By convention, every face of a solid must have its front side facing the exterior of the solid. An object with a mixture of face orientations will not be considered to be solid. You can correct reversed faces in various ways. You can select a bunch of faces, right-click, and choose “Reverse Faces”. You can select a single correctly-oriented face, right-click, and choose “orient faces”. Or you can use a tool such as solid inspector to fix them en-masse.


#8

If the shape has circular symmetry, you can draw a half-profile face and a circle on the axis and then use the follow-me tool to “lathe” it into a solid.


#9

Forgot the attachment!
3 Axis Planes.skp (121.4 KB)


#10

Ah, circular arcs that way! The fastest and easiest way to join those curves may be to use Fredo6’s curviloft extension.


#11

Wow- curviloft is awesome! Thanks for letting me know about that extension.

I used curviloft to cover the surfaces, made it a single component figure, and still entity info wouldn’t give me the volume. I then used Solid Inspector, and realized that I had internal walls within the figure, so I deleted those (thou it would be nice to not have to delete them when I just want the overall volume). Still no luck calculating the overall volume. Any ideas of what might be off? Again, thanks so much for y’all’s help- this has been extremely helpful.

3 Axis Planes.skp (256.4 KB)


#12

What’s the volume of a bucket with no bottom?

Your groups are not solids so there’s no way to calculate the volumes.

Explode the groups, select all of the geometry including the bottom and make that a group or component and SketchUp can tell you the volume. Make sure it is solid.


#13

Ah great, now I see. Works now!
Thanks yet again.