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This file is fairly simple. Why is it having fit curve issues in sketch?

Message 1 of 10
253 Views, 9 Replies

This file is fairly simple. Why is it having fit curve issues in sketch?

All sketch capability is quite slow, however, its worse aka almost unuseable when performing "fit curve to mesh" functionality.

Was fairly quick even last revision, however, this version seems to have an issue.

This is a fairly simple drawing and this workflow was fairly quick only a couple months ago.

Let me know what you find.

I resaved it and stripped it down as much as possible in another drawing, removing bodies, sketches, components, etc etc trying to isolate the issue to no avail.

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Message 2 of 10


please share the file for reply

File > export > save as f3d on local drive > attach to post



Message 3 of 10

Thats wierd. I attached the file.  Well, here it is again..
Upload is very slow, we have line-of-sight internet so I must have hit the post button too soon.

Message 4 of 10

Ok, so to perform a simple fit curves to mesh section, i went to the best circle I could find and it took a full 30 seconds to fit a circle.

That is definitely not normal.

Enable edit in sketch 1 and do the same and see what happens. I got three crashes along the way.


Message 5 of 10

Another issue is it will often switch program windows after completion. IE if I have a browser running in the background, it will minimize fusion and switch to the browser.


Message 6 of 10

@subversivespeed wrote:

Ok, so to perform a simple fit curves to mesh section, i went to the best circle I could find and it took a full 30 seconds to fit a circle.


If this were my design:

1. I would have started by moving the mesh geometry to a logical location about the Origin.

2. I would use the mesh only as visual reference and with the aid of calipers and the visual reference recreated fully defined sketches from scratch. I would not use fit curves to mesh sections on a complex mesh like this.


Edit: 3. If this were my work I would enable Capture Design History.

Message 7 of 10
in reply to: subversivespeed

If you have crash report numbers, please let me know, glad to look.


I tried your model and immediately noticed that with all those triangles, turning off all graphics effects vastly speeds up performance. There is quite a lot of geometry in the model. This makes a difference, and each model will be different. If you have an example of an extremely simple/small mesh scan that performs badly for you I'll look at it too.


Support and diagnostics > Graphics Diagnostic > Limit effects.


  • With default effects "on" I see about 6 seconds to create the mesh section.
  • With all effects "off" the sketch is created nearly instantly.
  • I can also see the difference when simply orbiting the model.


Another approach would be to reduce the number of triangles on the screen.

  • Reduce the mesh (reduce triangles)
  • Delete the mesh you don't need to use



Phil Eichmiller
Software Engineer
Quality Assurance
Autodesk, Inc.

Message 8 of 10
in reply to: Phil.E

So it might by graphics/GPU related. That makes sense.

I might try to roll back the GPU driver and see if that changes it.

Odd thing is that only a month or so ago a similar model was able to do the fit to mesh in realtime, nearly instantaneous. The size was actually larger, so I am somewhat lost as to why it changed.

Oddly enough when I added more sketch layers in parallel, after about the third sketch it seemed to run faster and I was able to sketch without any slowdown, using the mesh sketch in the background as a guide.

I will see if I can crash it a few times today so you can see the logs and get a better feel of what is happening.

Message 9 of 10
in reply to: Phil.E


DELETED the ENTIRE MESH MODEL from the file..

Still slow.

Reduced the graphics.

Still slow.

Done everything I could to try to isolate what might be causing this.

Tried changing the graphics type from DX9 to DX11 and back again.

For some reason the moment I try to edit the mesh section sketch, it has a massive slowdown.

It even makes subsequent non-mesh section sketches slow.

Done it with two different PCs that ran this sort of operation just only a few weeks ago.

It seems the only thing that fixes it is:


Once that was done, the ENTIRE sketch module had a massive increase in speed.

What this tells me is that, somehow, the mesh section sketch module is still performing something in the background as long as there is ANY mesh section sketches, even when the mesh section sketch is NOT the current sketch.

Message 10 of 10

Hi, please uncheck "Profile" in the sketch pallete and try again:


Thanks for reporting the issue! We will take a further look.

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