Negative Volume

I’ll be damned WTH?!

Can you post the file? That usually helps to solve the problems.

No can do…NDA

One would think it’s because standard issue of Rhino “Far from Origin” so I changed from mm to m here’s the result:

No naked edges

Flip the normals, Dir or Flip command
Rhino thinks the open object is inside out.

Yes, just thought of that, I flipped all surfaces’ normals outwards then joined into solid and they all got flipped back in.

the result is again negative volume.

The thing is that only at a certain part of that boat is doing that. above and below it the volume is positive.

I assumed it was open edge but it’s not then I thought it’s the “far from origin” flaw of Rhino, still not that.

I don’t know what’s happening.

Then there’s something “bad” about one or more surfaces.
I suspect if you run SelBadObject it will select.
ExtractBadSrf will isolate the problem.
Generally, detaching the trim curve from the bad surface, then retrimming using the detached curve will sort it out.


Then you probably have a self-intersecting surface or surfaces.
Try a shaded display mode that puts an obnoxious color on backfaces so you can find it.

That is not possible I created this surface moving each point I am aware of each point’s position and none of these surfaces self intersect.

Then we’re through here without the file.
You can send it to tech support with this URL so we know what to do with it:
Negative Volume

Tomorrow I’ll import this in CATIA and test it there, afterwards I’ll ask for permission to send it. But you better log that thing. Not long ago there was negative Areas calculated now it’s volumes. Very disappointing.

I have nothing to log without a sample file.
I’ve never found a bug so far like this that couldn’t be figured out by less than perfect surfaces, tolerances, or something else.


Without log you won’t even test to find if an issue exists. Are you that arrogant? If you haven’t found an issue it doesn’t exist :smiley: omg

I’ll send you the file, then I demand an apology!

You misunderstand.
I believe you there is a problem.
I can’t determine if there is a bug that needs to be fixed or not without an example.

Either way, I’m trying to help you sort it out.

The reason to log it John is that if anyone else encounter it you pile up on that there is an issue that requires more thorough investigation.

There is no actionable item without a way to reproduce it.

I need your file or one like it that acts like yours does.

Explain to me how to ensure you cannot untrim my surfaces then I can send a file right away.