slic3r 1.42.0 beta2, z contact distance issue.

[wonderland134]

Version

Version of Slic3r Prusa Edition used goes here
slic3r PE 1.42.0 beta 2 ver
Use About->About Slic3r for release versions

For -dev versions, use git describe --tag or get the hash value for the version you downloaded or git rev-parse HEAD

Operating system type + version

What OS are you using, and state any version #s
In case of 3D rendering issues, please attach the content of menu Help -> System Info dialog
window 10

3D printer brand / version + firmware version (if known)

What 3D printer brand / version are you printing on, is it a stock model or did you modify the printer, what firmware is running on your printer, version of the firmware #s
prusa mk3s

Behavior

• Describe the problem
• Steps needed to reproduce the problem
  • If this is a command-line slicing issue, include the options used
• Expected Results
• Actual Results
  • Screenshots from Slic3r preview are preferred

When I using support via to slic3r, strange thing was appear.
If I set the z contact distance to 0.2mm Then I get the actual z distance between last support interface and product bridge to 0.6mm.
I find a mechanism this problem.
If I pick the nozzle size to 0.4mm and line width 0.4mm Then I can get the real z - contact distance = setting value + nozzle size.
So I can reach the minimum real contact z distance near to nozzle size value when I set the z contact distance value to near to 0
Thus, When I use the 0.4 mm nozzle, I can reach closest contact distance approximately 0.4mm.

Below is my wanted.
I want to set actual contact z distance to 0.2mm. But I can't reach this value.
So I think this problem caused unflexibility to set the contact z distance.

I think this setting mechanism will be changed.
Also this problem caused bad quality support contact interface area.

Is this a new feature request?

Project File (.3MF) where problem occurs

Upload a Slic3r PE Project File (.3MF) (Plater -> Export plate as 3MF for Slic3r PE 1.41.2 and older, File -> Save / Save Project for Slic3r PE 1.42.0-alpha and newer)

[faboaic]

That issue has been here a few times.
But I really am hoping for a solution since this is the one and only real problem where slic3r prusa edition / PrusaSlicer fails so much compared to other slicers.

With this issue fixed there will be no need for other slicers anymore.

Main problem is that here the bridging is used as first layer on support.

Simplify can do that so much better.

[liftbag]

If you want z distance to 0.2mm, then enter -0.20mm. Negative values are perfectly considered and calculated.

[wonderland134]

For liftbag.
I already tried that method.
I hope also try to that way.
Maby result will be amazing!
-0.2 is apply exactly, the way that, insert the support to the product portion.

[liftbag]

wonderland134, you can verify form the slicing preview.
The difference between the height of the last dense support and the first layer in contact with it is equal to the size of the nozzle plus the value you enter in the check box. If the value entered is negative, then it will be the size of the nozzle minus the value you enter in the check box.

[bubnikv]

To improve quality of the object over support, we have added a new settings: "thick bridges". If enabled (that is by default), PrusaSlicer behaves as before. If disabled, bridges are printed as in any other slicer: The extrusion rate is given by the normal layer height x extrusion width * bridge flow ratio.

Implemented with ceea9de f01f021

Duplicate of #341 #4126