Generating unnecessary support block
Hello, all. Using PrusaSlicer 2.3.0 and noticed a huge block of support being generated for no purpose. It doesn't support any part of the print.
How did I manage this? Thank you.
RE: Generating unnecessary support block
Check your model for errors.
RE: Generating unnecessary support block
By the way, this appears to happen only when I request 0.15 layer heights, not with 0.2 or 0.1 layer heights.
Bug?
RE: Generating unnecessary support block
@neophyl
MeshMixer indicated zero errors.
RE: Generating unnecessary support block
Save your current 3MF project file, zip it up, and attach it to a reply here so we can see your part & settings and give better recommendations.
and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan
RE: Generating unnecessary support block
Many thanks, Other Bob
RE: Generating unnecessary support block
A few things seem to fix the issue, but the simplest seems to be to rotate the part. Even 1 degree is sufficient to stop the odd support generation. Not quite sure what causes it though.
and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan
RE: Generating unnecessary support block
Bizarre, huh? I guess I have to pay closer attention to the preview and not just assume it's all necessary. Maybe it's the equivalent of a standing wave.
Thanks, Other Bob
RE: Generating unnecessary support block
I exported the model from the project and took it into Blender. While it was manifold there were over 23ooo intersecting faces, also 160 zero faces. Normally PS doesn't have a problem with those but this time it seems it has, at least with a few of them. I suspect theres a zero thickness plane thats fooling PS and its that its generating support for. As soon as you rotate or otherwise change the relative vertices positions its no longer evaluated the same.
The right click and fix through netfabb option available to Windows 10 PS users seems to fix the issue too. Even without rotating or anything else. If the netfabb fix is removing these or even doing some math rounding on positions it would result in the same thing. I suspect this is one for the Dev's as it would require a deep dive.
Whenever you have slicing weirdness the first thing to try is fix through netfabb if on Win10.
RE: Generating unnecessary support block
@neophyl
WOW! Fantastic, thanks for teaching me this. Very cool.
RE:
I'm having the same issue. What's interesting is if I rotate the part 1 degree, the unnecessary supports go away, but if I rotate 90 deg, they stay.
I'm using PrusaSlicer v2.5.2+win64. Seems like a bug?