topic Re: Boolean issue in 3ds Max Modeling Forum

Boolean issue

Anonymous — Mon, 17 Mar 2014 22:39:30 GMT

Tried all forms of booleans and proboleeans. Cut, subtract, everything. Both objects have been tried with mesh, poly, 1 poly the other mesh...

Really don't know why the boolean "cuts" the first object, instead of slicing the chunk I need

Any tips?

https://www.dropbox.com/s/6zyt6kst24ls63p/1.jpg
https://www.dropbox.com/s/lzpmp8zkkl23tam/2.jpg

Re: Boolean issue

PROH — Tue, 18 Mar 2014 01:57:26 GMT

Hi. Max has never been as good at Boolean operations as i.e. AutoCAD. In cases like yours I can think of 2 major reasons to fail:
1) One or more of the object are not enclosed. Make sure they are all welded and without any holes.
2) The complexity of one or more objects are to complicated for Max to calculate it correct.
If it is not possible to get Max to do it right, then you'll have to manually remove the unwanted faces and bridge the gap.

Hope it helps

Re: Boolean issue

Anonymous — Tue, 18 Mar 2014 10:38:44 GMT

1. I'm pretty sure it's closed. Made a spline, modded to poly, then extruded it to make it 3d. How can I confirm this?

2. Possible that it's too complex (10k polys). Not going to do it manually, so any easy way to "dumb down" the polycount? Wouldn't want to restart everything

Thanks!

Re: Boolean issue

Steve_Curley — Tue, 18 Mar 2014 11:21:39 GMT

It would help enormously if you could post the scene - just the objects involved in the Boolean operation (before you boolean them, of course). Zip the .max scene file and attach it to a reply.
I just made a rough equivalent of what's in your 1st image and using ProBoolean (Intersection) it correctly "cut out" the shape of the central object (pink) from the 2 white objects (which in my case were a single object - 2 sub-splines + an extrude modifier).

Re: Boolean issue

Anonymous — Tue, 18 Mar 2014 11:34:49 GMT

Here you go. 2 versions of the same models. Thanks for the help.

Re: Boolean issue

Steve_Curley — Tue, 18 Mar 2014 13:31:41 GMT

Line013 and Line 014 are open - there's no poly on the one end. Those will need Capping at the very least.
I still can't get the Boolean to work correctly - I'll look properly later today (busy busy...).

Re: Boolean issue

Steve_Curley — Tue, 18 Mar 2014 15:59:52 GMT

I'm at a loss trying to get the imported objects to boolean correctly at all, yet if I re-create the Line013 object within Max it will boolean perfectly with the imported Sphere003. I have a suspicion it is to do with the relative mesh densities of the 2 objects - the number of vertices used to create the curves, because when I recreated Line013 I did so with many fewer vertices and used the Bezier Tangents to recreate the curves. This is somewhat confirmed by using the Section Shape to create a Slice though Line003 - adding an Extrude to that shape fails to cap the ends. My modified shape however extrudes correctly and booleans correctly.

Left image is the original section (left) and mine (right). Middle image shows the result of adding an Extrude. Right image is the result of a ProBoolean (subtract) with Sphere003.

Re: Boolean issue

Anonymous — Tue, 18 Mar 2014 16:11:32 GMT

I see, so the problem was that the spline was created poorly from the beginning. Ok, will re-study the basics and then move on.

Maybe creating a simpler line, boolean, then apply some chamfering to smoothen out?

THanks a lot for your time, Steve!

Re: Boolean issue

Steve_Curley — Tue, 18 Mar 2014 16:20:06 GMT

Not poorly, just too complex for the Booleans to handle (it seems).
Simpler line yes, but if you do it carefully you should be able to match the original curvature very accurately so removing the need for Chamfers later (which have their own problems as you'll no doubt discover 😉 ).

Re: Boolean issue

Anonymous — Tue, 18 Mar 2014 16:25:37 GMT

So how would you make a perfectly smooth curve in that part of the mesh? just 2 normal beziers and 2 bezier corners?

Re: Boolean issue

Steve_Curley — Tue, 18 Mar 2014 16:40:39 GMT

Effectively yes, as that's how the Section shape created the Spline I worked with.
I removed all the vertices defining the curve except for the 2 endpoints (obviously) and one at the center of the curve (converted that one to a Corner). I then used Fillet on that middle one to give a close approximation, then just moved the 2 vertices created by the fillet, and their Tangent Handles, to get the final result. I did it by extracting the Shape twice so I had the original to work to as a guide. The differences were very minimal - I had to zoom in a long way to see any divergence in the splines - and I didn't spend too much time doing it as I was testing a theory, not my modeling skills 🙂

Re: Boolean issue

Anonymous — Tue, 18 Mar 2014 16:43:05 GMT

Beautiful, thanks again!

Re: Boolean issue

Anonymous — Tue, 18 Mar 2014 17:52:25 GMT

Solved in a matter of 2 minutes: new line, bezier, close it, convert to editable poly, extrure to one side, cap the other, boolean, done

Had my basics wrong, overcomplicating something that takes no effort

Re: Boolean issue

Anonymous — Tue, 18 Mar 2014 19:07:46 GMT

Spoke too fast. During rendering it clearly shows that chamfer and splines are not smooth enough when curved.

ANy other solution? Something like turbosmooth on just a few faces and not all the poly/mesh?

Re: Boolean issue

Steve_Curley — Tue, 18 Mar 2014 20:05:36 GMT

Try stepping back into the Editable Spline and increasing the number of Steps (Interpolation Rollout). Don't go mad with it though as you might run into the original problem.

Re: Boolean issue

Anonymous — Mon, 24 Mar 2014 15:46:28 GMT

if it's possible to detach the part that you gonna boolean max has less to calculate. then you can attach it back when you'r done