Hi there,

Here's part of of a model I'm working on, I built it as solid, MoI tells me it's a solid, it behaves like a solid, it even smells like a solid :) then why does it have a surface missing, has anyone else encountered this ?

Danny
I had a similar problem on the wing (leading edge)of that Spaceship exercise of today that I posted on a thread an hour or so ago.

We both need to reproduce the example for Michael I think!
Brian

I have no idea for your solid problem Danny, however I can't turn around your objet correctly Oo ... the 3d view is somehow upside down and I can't restore the navigation :o)

Am I alone ?

This is somewhat similar, but not identical, to my last problem in trying to convert my wing to a solid.
Hope it helps in analysis.
Brian

Hi PaQ,

> however I can't turn around your objet correctly

I know it's weird, I think it's got to do with modeling in the right view, then in the 3D view it won't rotate around the x and y axis, I was discussing this issue with Michael Here

.

Hi Brian,

Your problem is you want to create a solid, my problem is that my model is already a solid, but there is a face missing, like, if you boolean diff a cylinder from my model it will produce a hole with sides as a solid should behave.

.

Hi DannyT,

I separated the surface and
the image shows te result

Perhaps you should reconstruct the
edge in a single curve

Hi Danny,

>>then why does it have a surface missing

Because it is an invalid surface...

When you explode that solid, hide all surfaces except that invalid one (represented by its edges only), then push Sel all or Ctrl+A (only way how to select that surface) and pick one edge and push Sel all or drag a selection window to select all edges. Now, Copy those edges to clipboard and hit Delete and Paste to back an underlying untrimmed surface and trim boundary respectively. As you can see, the underlying surface has nothing to do with outer trim boundary of your missing surface.

Petr

Thanks Petr, I actually did that at the end but I deleted the whole invalid surface and reconstructed it, joined everything and it is happy again.
Thanks Guys.

Cheers

Hi Danny, yeah I think you guys have figured it all out, here is that problem surface:



The trimming curves are totally on the outside of the underlying surface...

Because all the edges are joined to other edges, it basically still counts as a solid, although with a really bad tolerance since the gap between those edges and the surface is substantial.

The bug is in whatever made that particular surface in the first place which is a bit hard to determine now. If you happen to know which modeling step that opening appeared in (like after a boolean, after an initial extrusion, after a certain step) then that could help to narrow down which operation has the bug in it that created that bad surface.

- Michael

Hi Danny, looking at all the surface control points for other surfaces, it looks like this may be a section from what started out as a thicker object then was cut down with a boolean?

If you happen to have an earlier version of the object before that boolean, that could help if you could send that to me and I can see if I can recreate the problem.

- Michael

Hi Michael,

I'll try and recall the steps I took there, the model I posted is just I piece I cut off the main model, I can send you the whole model if you like.

.

Hi Danny,

> the model I posted is just I piece I cut off the main
> model, I can send you the whole model if you like.

Yeah, if it is ok please send it to me at moi@moi3d.com, I can try to see if I can recreate the problem surface.

If I can find the steps to make it happen, it will help a lot to try and find the bug.

Thanks,

- Michael