Hi Guys,

Thanks for all your input. I tried it in V1 and that actually worked. So I got a solution.
After I saw the results in V1, I was actually not quite pleased with the results, I mean
the looks. So I changed a few things, like decreasing the bottom radius on the cutting
tool and I also moved the cutting tools further out, for a less deep indentation.

Doing this, I thought I will try this again in V2. And ... I have two different versions.
One worked partially - looks a little bit like Brians version, some faces remained, some
didn't. The second try worked just fine.

Seems it depends on how close you get towards the center - see screenshot. I get the
impression if I get past the highlighted circle it doesn't work, if I stay outside it works?

And btw - Danny the dimensions are based on inches, but like Michael said, this shouldn't
affect the outcome. Maybe ... and I forgot about the restrictions on very small dimensions,
maybe my choice of dimensions caused the problem. If I remember right, I used a fillet
with 0.03125 (1/32) - do we still have the problem with too small dimensions?

Anyway, thanks again for your help ... and see attachments.

Hi armin, thanks for the additional examples.

So it turns out that the problem was not caused by any changes in the most recent v2 beta, the last several v2 betas have the same behavior as well.

I'm going to keep on searching back until I can find where it changed in behavior from v1.


> I used a fillet with 0.03125 (1/32) - do we still have the
> problem with too small dimensions?

I think that should be fine... But if you go much smaller than that you may want to think about having the object scaled up.

However, I have added quite a few things to v2 so that it handles smaller sized things better in many aspects though. Like with fillet for example if you ask for a small fillet radius, the tolerance used in creating the fillet surfaces will be ensured to be some fraction of that radius value so that it basically will adapt to it. But right now not every single function has been audited for that yet.

- Michael

Hi armin, I've been looking extensively into this boolean problem you reported here on this handle model.

I tracked it down to a change about a year ago in MoI v2 where when it loads a 3DM file, it detects whether surfaces in the model are pieces of an exact cylinder, cone, or sphere and if so it creates a special analytic surface class for that surface instead of having it as a regular generic NURBS surface.

The main difference with the analytic surfaces is that surface/surface intersection with them will do some special cases for them to get a more simple and precise intersection result. That's the idea anyway, but there are some bugs in some particular cases of the analytic surface intersections and that's what was causing this boolean failure.

For now I've disabled the analytic intersection for these problem cases so that it will use the general purpose intersector which then lets this boolean work fine.

I've reported these analytic intersection problems to the authors of the geometry library and I'll probably be able to re-enable them in v3 when they get fixed.

But anyway, your handle boolean will work in the next v2 beta, thanks for reporting the bug.

- Michael

Ah....having similar problems here with a boolean failing, but not sure if it's the same. I don't wanna steal your thread, thought it would be good to keep with the subject of boolean problems. I'm trying to cut the gear shape with the box, with no result.

After importing into v1 and trying it, all went well. I just had to then reimport into v2 beta to continue working with it (cause v2 is so saucey good).

Just hope this will be resolved b4 the final V2 is released.

@ Tree
Maybe you must post the 3dm file (zipped)

Hi Tree, could you please post (or mail to me at moi@moi3d.com) the 3DM file with your gear and box in them so I can test it over here?

It sounds like it could be the same problem but I can't be sure without testing it.


If it is a different issue, it would be very helpful to have the model so I could work on fixing it up in v2.

- Michael

Hi Michael,

I mailed you the file. Hope it helps.

Thanks Tree - some initial tests seem to indicate that it is actually a different problem than the one mentioned here, so I'm glad you sent it to me.

I will be digging into it to try and figure out what change in v2 broke this case.

- Michael

Hi Tree, I was able to track down this boolean problem with the gear and the box that you posted previously here.

It behaved differently in v2 versus v1 due to a small change in the surface/surface intersection tolerance. I've got it tuned up for the next v2 release.

Thanks for reporting the problem.

- Michael

Great! Is the surface/surface intersection tolerance something that can be or will be able to be controlled by the user? In the cases where booleans do fail and no result is given or pieces just vanish, would it make sense to give the user control somehow to adjust how it performs the boolean? Sometimes any result would be better than none. Although the opposite can also be said to be true.

Hi Tree,

> Is the surface/surface intersection tolerance something that
> can be or will be able to be controlled by the user?

That's theoretically possible, but it's a rather arcane esoteric value for people to adjust, and it is easy to adjust it improperly if you do not fully understand what it is controlling.

Things tend to behave really strangely if it is too loose, you end up with kind of saggy intersections.


> In the cases where booleans do fail and no result is given or pieces
> just vanish, would it make sense to give the user control somehow
> to adjust how it performs the boolean?

Well, part of the update is that if it failed or if there are naked edges in the result when there were none in the inputs, it will repeat the boolean again with an automatically tightened tolerance. It will go through that cycle a few times.

- Michael

Almost looks like a PBW (Earthsiege / Starsiege) :)

http://www.angelfire.com/sd2/nightcabbage/Stuff/3dsmax/pbw2.jpg