Adobe Illustration 2023 | Problem with Shape Builder Tool and Curved shapes

[lesyasinitsky]

Hi! I have two problems

The 1st problem
Something strange is happening with the shape builder tool. When I select an object, and then click on the tool and want to use it on the object, a gap appears inside the shape. Please check the screenshot and the video https://www.dropbox.com/scl/fi/rgifrqpkvz89kgg9ndn0i/14.02.24-1.mp4?rlkey=pfvj0qm8cjkka9x7zvq24v14q&... 

The 2nd problem
When I cut a part of an object using the shape builder tool, the object changes to a wrong shape and adds a weird bump. All these things happen with curved chapes only. Please check the video https://www.dropbox.com/scl/fi/74jj5tq6jp4xpaylnksiw/14.02.24-2.mp4?rlkey=cc8g6hqpor54cq7u2q7jpk4re&... 

[Monika Gause]

Is the option "Consider open filled Paths as closed" on or off? And what happens when you change it?

How is the Gap detection set up? And does it matter when you change it to a smaller gap?

[lesyasinitsky]

Hi! Nothing happens if I change the Consider open filled Paths as closed and the Gap detection https://www.dropbox.com/scl/fi/3snkg36mr6zm77mxij83g/14.02.24-1-2.mp4?rlkey=u39s4h3c1ct9862x9tj0cpo8... 

[Monika Gause]

Can you upload a demo file?

[lesyasinitsky]

You mean .ai file, right?

[Monika Gause]

AI file, yes. AI files can't be shard on this forum. So you can rename it to PDF to upload it here or share it on Dropbox or the like.

[lesyasinitsky]

here you go https://www.dropbox.com/scl/fi/myguf2dpg69kb9q3ai5n7/demo.ai?rlkey=615aankkw8hbdbyu4ivto9ssf&dl=0 

[Monika Gause]

I could manage it with Gap detection turned off.

There are still issues, because the drawing is just not precise.

[lesyasinitsky]

Can you send a video? Because I recorded my screen and you saw that it didn't help on my pc..

[lesyasinitsky]

What do you mean by not precise? 

[Monika Gause · Accepted solution]

On the right side it is not very precise.

I think what is irritating Illustrator is that long handle. If you shorten that and put points to stabilize it, you do not get that erratic curve https://youtu.be/0YKUUlSF5QI 

It still jumps. Whatever causes that. You did not at one time align the shape to the pixel grid? 

[lesyasinitsky]

so strange........ no, I didn't align

[Monika Gause]

I think then helper points are an option to keep paths where they should be

[lesyasinitsky]

Thank you! Could you possibly take a look at my another problem? https://community.adobe.com/t5/illustrator-discussions/weird-selection-of-the-objects-adobe-illustra...  

Another person kinda helped me, but his way of solving the problem created several new problems...

[Monika Gause]

If the CPU preview solves it, then a lack of precision in the GPU preview was the cause. 

GPUs are fast, but not precise.

Maybe updating the GPU driver can solve it, but probably not. And then each update to either the system, the driver or Illustrator can ruin it again. That is unfortunately just the circle of life.