Hello there,

I have two solids that I am unable to fillet after Union. Independently they are fine.

Any ideas? I think I've broken some geometry somewhere along the line.

---------------------------------------------------------------------------------------------------------
I'm getting a 500 internal server error trying to upload attachments.

So I'm linking an image and a .3dm from my sync account.

https://ln3.sync.com/dl/02a24c8b0/qi3b7w5i-e88twr5h-bnp43k6h-hpfqm5xj

Hi dodeqaa, I don't think you've got any broken geometry that I can see. I think the problem is that after the bool union you've got a type of fillet corner here that the fillet engine does not handle well:



It would probably like it if this edge was not there, It's something like it doesn't know how to cut that edge back to make room for a corner juncture:



- Michael

Try with this version. Another thing that was a bit tricky is the surfaces were not quite smooth to each other at that edge as well.

- Michael

Hello Michael,

Thanks! That works great!

May I know how you reconstructed the curved surface please?

Hi dodeqaa,

re:
> May I know how you reconstructed the curved surface please?

Well it's kind of tricky.. First used Edit > Separate on the 2 surfaces to break them out from the main object. Then selected the edges of the curved one and used Delete to untrim them and recover the full underlying surface. That then allows to select the side edge curve of it and use Ctrl+C/Ctrl+V to duplicate it as a curve and then delete the surface. Then positioned the lines from the bottom planar surface next to that side curve and edited control points to move the first interior point of the curved one so that it was aligned with the line's direction so they were smooth to each other. Then to fuse them together i used a trick where exporting a joined curve to SAT format and reimporting it will fuse tangent pieces together into longer curves. Then extruded that and trimmed it and joined it back in.

- Michael

That whole process for combining faces is definitely something that I want to make easier to do.

- Michael

Thank you for the detailed reply! I'm stumped on the steps, I managed to separated the 2 piece sin question but selecting the edges of the green curved surface and pressing delete doesn't do anything?

Hi dodeqaa,

re:
> Thank you for the detailed reply! I'm stumped on the steps, I managed
> to separated the 2 piece sin question but selecting the edges of the green
> curved surface and pressing delete doesn't do anything?

You need to separate them out into individual surfaces, so for this case you need to run Separate twice. The first one will separate the 2 selected faces out from the main object but keep those 2 faces still connected to each other. Then run Separate another time to break apart those 2 surfaces into individual surfaces not connected to anything else.

- Michael

Hi Michael,

Thank you for your reply. I have more question I'm afraid. Please bear with me.



I managed to untrim the curved surface (c) and I copied out the profile curves (d) + (e). 

I aligned them and joined them using join, (tried exporting using SAT but I’m not understanding what step) and then I extruded it (f).
Could you explain the step involving the SAT in detail please?

I’m guessing i need to make a curved surface like in (f) but without the corner point creating a line in the middle (x)?

Next I would need to trim it with (b) ? 

If the points of the curve profile (y) are out of alignment in (b),wouldn’t that make union with the trimmed surface impossible?

Hi dodeqaa,

re:
> Could you explain the step involving the SAT in detail please?

That's the part that's pretty tricky - a side effect of exporting a joined curve out to SAT format is that in the SAT file it will be curve made up of just one segment, multiple segments will be fused together. When you then import it back in, it will get broken into separate segments at any tangent discontinuities but areas that are tangent will remain as a long segment.

When you do an extrude you'll get a separate face for each segment in the input curve, so to eliminate edges between faces you want to get this curve to be composed of just one segment instead of multiple segments which is what you get currently with the Join command.


> Next I would need to trim it with (b) ?

Yes, I trimmed it with the naked edges of the main object.


> If the points of the curve profile (y) are out of alignment in (b), wouldn’t that make union with the trimmed surface impossible?

If it's a small enough change then it can still get joined. If it's too large of a shift then yes some other reconstruction steps would be needed.

- Michael

Hello Michael,

Thank you for the explanation and your patience. Works like a charm!

Made the mistake of moving the tangent points to line up with the curve point above, that left a gap in the geo.

Changed it up and move the curve point above the tangent points (I guess that's what you meant by first interior point).