PrusaSlicer 2.9.1-beta1

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Summary

This is the first beta release of PrusaSlicer 2.9.1. This release introduces new algorithm for generation of SLA support point and couple of bugfixes.

To let you enjoy the beta without worries, the beta builds save their profiles into PrusaSlicer-beta directory, so you may use the beta side by side with the current release without ruining your production configuration.

New SLA support point generator

We are introducing a brand new SLA support spot generator, which replaces the existing solution and provides more precise and predictable support placement. The new algorithm better differentiates the areas requiring support – small, medium, and large islands, as well as overhangs – and adapts the support strategy accordingly.

• Small islands are supported by a single point placed at their center of mass.
• Medium islands use the Voronoi diagram to optimally place two or more supports.
• Large islands are divided into thin and thick sections, where supports are placed either along the central axis or around the perimeter for greater stability.
• For detected overhangs, the algorithm dynamically adjusts the support density based on Z height and overhang angle, minimizing unnecessary supports and ensuring even distribution.
  

The new algorithm is not randomized and it produces same results when given the same input repeatedly. In general, it is a great improvement over the old algorithm, which often failed in a spectacular manner even in seemingly very simple cases:

Additional changes make it easier to manage supports and enhance visual feedback:

• Support density can now be adjusted with a single slider – moving it instantly updates the preview, enabling smooth and quick fine-tuning.
• A new toggle for displaying the support structure allows users to hide or show the entire support construction for better model visibility.
• Manually added points are no longer ignored – when the user presses Automatic Support Generation, the algorithm considers them and adjusts the surrounding support density accordingly.
• Support types are color-coded, distinguishing islands, manual edits, and overhang supports.

Bugs fixed with respect to 2.9.1-alpha1

• CLI options export_sla and export_gcode were reintroduced after they were erroneously removed in 2.9.1-alpha1.
• When sending multiple beds to Connect, PrusaSlicer allowed characters in the filenames that Connect would refuse. This is now fixed and the names are refused immediately.
• Remove an extra 1.5s pause after toolchange on an XL printer. This pause has a meaning for MK4, but including it for the XL makes no sense and could lead to issues. #13987
• Fixed Compare presets dialog, which did not correctly filter presets when the user changed selection.
• The new option to propagate thumbnails from 3MF to the G-code when using CLI was rescaling the images incorrectly and they ended up stretched. Images are now cropped to prevent this from happening.
• Scarf seams are now suppressed on the first layer to prevent adhesion problems. #11621 (comment)
• Fix couple of links to the web manual pages.
• Disable scarf seams on thick bridges. This is beneficial for print quality and it could also cause scraping the print bed if such bridge was on the second layer. #14190
• Added sequential arrange data for HT90.
• Fix crash during interlocking calculation in specific cases. #14163
• SLA: Fixed object placement on the bed after using auto-orientation. It stayed partially under the bed.

Translations

• Updated POT
• Updated CS, PL, DE, IT, ES, FR, JA dictionaries

Linux build is now distributed through Flathub. Please see the respective page on our Prusa Knowledge Base for instructions.