Cant split a body, Oparation failed. But I cant find out why it's not working!

[Anonymous]

Cant figure out why this is happening. I am trying to split a body with the split tool and as a cutting tool I want to use a sketch i projected from the body itself. But when I try to do it, it just shows me an error message and tells me to change the geometry. but geometry of what? the sketch or the body? I dont understand... what is the difference between the sketch that allows me to do the cut and the one that doesnt? I tried copying it and trying it again or even moving it a bit but it makes 0 difference. Please help!

[chrisplyler]

Coincident control point?

I'm guessing you made a sketch on a plane through the body and projected the intersection of that body and the plane? So your sketch outline perfectly matched the body outline where the plane sliced through it? And then you tried using that sketch as the cutting tool?

Seems like whatever math Fusion is doing behind the scenes doesn't like the edge of the cutting tool being the same edge as the body to be cut. Maybe the cutting tool needs to extend THROUGH and OUT of the body? I'm just guessing.

You can just use a plane as the cutting tool, you know.

[Anonymous]

Well, not exactly what I did... I made the body with the sculpt tool. Then just projected the creased curve to the midplane and tried using the resulting sketch as a cutting tool.

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@chrisplyler wrote:

Coincident control point?

I'm guessing you made a sketch on a plane through the body and projected the intersection of that body and the plane? So your sketch outline perfectly matched the body outline where the plane sliced through it? And then you tried using that sketch as the cutting tool?

Seems like whatever math Fusion is doing behind the scenes doesn't like the edge of the cutting tool being the same edge as the body to be cut. Maybe the cutting tool needs to extend THROUGH and OUT of the body? I'm just guessing.

You can just use a plane as the cutting tool, you know.

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So I also tried extruding it and lofting it to maybe create a face to cut the body but not even that works. It`s like the whole sketch is useless. cant seem to be able to use it like any normal sketch...

How can I use a plane to cut it if I'm trying to do a curved spline-like cut?

[chrisplyler]

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@Anonymous wrote:

How can I use a plane to cut it if I'm trying to do a curved spline-like cut?

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Well, no, that wouldn't work. But now I'm kind of confused. Can you show more pictures of your intent, or a screencast, or even share your file?

[Anonymous]

Hey Chris! thanks for your constant responses! I'm attaching a Screencast this time where I finally manage to cut the body, but while doing so, it wrecked my whole edge into tiny disgusting little edges with tiny faces in between, which is gonna be a pain in the ass when it comes to adding detail to the model, etc.

Take a look at it and let me know what you think might be the problem. I suspect that its just too much calculating for fusion to do because of the complicated curves and surfaces that I created with the sculpt tool. 

[Anonymous · Accepted solution]

Hey! updates over here! I finally managed to crack it! Apparently the curves I was trying to use as cutting tools and edges were too complicated for fusion to handle. What I ended up doing is going into patches mode and taking the whole thing apart and dividing it that way. After that I just did a bolean to get the other half to fit and VOILA! it worked... I guess I found out what the limits of the splitting tool are. Thanks for your help and hope this helps anyone who is having the same trouble!

[chrisplyler]

Hmmmmm.... so the line you're cutting with... it was projected onto a sketch plane that's perfectly centered and parallel to the body, right? And it was projected onto that sketch plane from that outside edge it appears to match, right?

Then I would think it should cut straight out through that line it was projected from. I can't imagine - geometrically - why it would leave odd edges. Unless the FACE right along that edge line is curved back in on itself such that it gets intersected by the cut. Examine the cut up close during the process while it displays the preview in red.

Does it make any difference if you try the same cut with the Extend Splitting Tool option checked?

[Anonymous]

It didn't even let me do the cut with the original projection I made on to the sketch plane... I tried everything, copied it, offset it, divided the sketch in two, you name it. It still would just show me the error message.

I had to export the sketch as a .dxf file and import it again to Force fusion to cut through the edge. That's when I got the strange odd faces. I did it to at least be able to try the cut. I don't know what the hell was going on but I circumvented the problem by going into the patch mode and breaking the body down and stitching it back up together. It has to be a problem with the T-Splines, because Fusion doesn't like to work with bodies and shapes made with the sculpt tool.

You cant offset planes off surfaces no matter how straight they happen to be, if they came from the sculpting mode it wont work (this among other functions don't work on sculpted shapes). So I theorize that the shape was giving Fusion a bad time. Its all good now, I fixed it. Just in a different way from the one I first intended to.

Thank you very much in any case, Chris! Cheers