PRUSASLICER SEZNAM ZMĚN

• Based on the feedback received after 2.8.0 release, the menu bar was reinstated and the menu no longer hides under a button. Thanks everyone for the feedback, it was very helpful and it will be taken into consideration during possible UI-related decisions in the future.
• When logging-in with the PrusaAccount using third party authorization (Google, Apple, Facebook), an external browser window is opened so the user is not forced to enter their credentials into windows created by PrusaSlicer.
• The built-in web engine no longer remembers the user after logout.
• There are two new parameters: Filaments->Advanced->Abrasive material and Printers->Extruder->High flow nozzle. Both flags will be used to check whether a sliced G-code is compatible with the given printer (abrasive material requires hardened nozzle) and also to ensure that “Set as current” function in PrusaSlicer-embedded Prusa Connect will select the suitable profile for the given configuration.
  Note that this feature is supported since MINI/MK4/XL firmware version 6.2.0-alpha1, and that the implementation in Prusa Connect is not completely finished yet, meaning that the dialog where printer is selected does not use this information – it will later start working without the need to download a new slicer version.
• Automatic orientation of bridges has been improved. Issues with unanchored bridges caused by inconvenient choice of their angle should now occur less frequently, although there is still a large class of scenarios where the solution is suboptimal.
• The output of --query-printer-models command line option was extended to contain bed shape and dimensions. Note that custom bed shapes are currently not supported.
• The ‘new version available’ notification can now be used to direct the user to our website, instead of just downloading the executable. As of now, we release two different Linux AppImages, so the user needs to be able to choose which one they want to download.
• A new infill type called Zig-zag was created. It behaves the same as Rectilinear, except that the pattern is aligned between layers (Rectilinear is optimized for short travels, which leads to inconsistencies). The new infill may thus take slightly longer to print because of that, although the effect will be negligible in most prints. It is possible that Rectilinear and Zig-zag will be merged into a single infill type in one of the upcoming releases.

IMPORTANT NOTE FOR LINUX USERS!

PrusaSlicer now depends on WebKit library, which greatly complicates its distribution. Latest Linux distributions (such as Ubuntu 24.04, Fedora 40) ship with newer version of WebKit than older (but still supported) distros. Bundling WebKit into the AppImage is difficult and may not be possible.

Therefore, we now provide two separate AppImages, both depending on webkit library. You may need to install the respective package before you are able to run PrusaSlicer.

Build	min libwebkit2gtk version	distributions examples
older-distros	4.0	Ubuntu 22.04, Fedora 39, Debian 11
modern-distros	4.1	Ubuntu 24.04, Fedora 40, Debian 12

The AppImages can extract themselves when run with --appimage-extract command line parameter.

It is quite likely that PrusaSlicer will switch only to Flatpak deployment from the next version on. The AppImage made sense when it could be used in the “bundle what you need, distribute a single file” way, but having to distribute several different AppImages and maintaining the required build infrastructure (and still worrying about what needs to be updated when some Linux distribution update is released) means burning time that we would much rather invest into actual work on PrusaSlicer.

This release introduces several UI improvements, Prusa Account login and Prusa Connect integration, improved G-code viewer, better seams, single perimeter for top and bottom layers, and more many more improvements and bugfixes.

Improved UI

We have decided to do several tweaks to the user interface. It is by no means a complete redesign, so the controls are mostly where you are used to find them. The most visible change is the top bar. The system menu was removed (on Windows and Linux only) and it is now accessible through a separate button at the very left of the top bar. The settings tabs are now larger and styled. The larger top bar allowed us to integrate the Search field into it, so it is readily accessible and it looks the same regardless of which tab is active (unlike in previous versions). The right part of the top bar features the Simple/Advanced/Expert switch (which is newly a dropdown) and the PrusaAccount login box.

Next, both sliders in the Preview have been completely reworked and are now part of the 3D scene, instead of being placed in a neighboring panels. Apart from looking nicer and more modern, removing the side panels means that the canvas size is larger. It also comes with a nice benefit that switching back and forth between the 3D view and Preview no longer shifts the view, the views are now perfetly aligned.

Credits go to BambuStudio, whose sliders were used a starting point for the implementation (although we later ended up rewriting most of it to fit current PrusaSlicer architecture).

Topping the list of the UI improvements, the spacing and icon size in the toolbars in the scene was slightly changed. The toolbars are now nicer and look less cramped.

Prusa Connect integration

Prusa Connect is our online system to control printers from the browser and distribute print jobs among them. Starting with this release, Prusa Connect is accessible directly from PrusaSlicer to streamline the workflow. A login box was added to the right of the top bar. When the login is successful, one more tab (Prusa Connect) will appear in the top bar. This tab will present your Prusa Connect dashboard and all features that you are used to.

When logged in, PrusaSlicer keeps track of the status of your printers and it also knows with which of your printer profiles they are compatible (printer model, MMU capabilities and nozzle diameter are checked). When a printer compatible with a given printer profile is in Prusa Connect, a little colored dots will appear in the printer profile dropdown in the right panel, displaying current status of that printer. The summary of the state of connected printers is shown just below the dropdown.

When a G-code is ready to be exported, a ‘Send to Connect’ button appears in the right panel. Clicking this button will open a dialog window presenting all your Connect printers compatible with the current project and allowing you to send the generated G-code to one of them.

To streamline the workflow in the other direction, there is an extra button in Connect labeled “Set as current”, which is shown for every printer. Clicking it will switch back to Plater tab and select first compatible printer profile automatically. The language settings and light/dark mode in the Prusa Connect tab is automatically switched so they match what is currently selected in PrusaSlicer.

Previous way of sending G-codes to Prusa Connect using a physical printer profile is deprecated. Users should stop using physical printers for Prusa Connect, although the support will be maintained for some time. Nothing changes with regard to PrusaLink or the other print hosts.

Note that logging in or using Prusa Connect is completely optional. PrusaSlicer will work fine without the login, as it has worked before. We are considering to add a Preferences checkbox to hide the login box completely to not bother people who intend to never use it anyway.

Improved G-code Viewer

The integrated G-code Viewer has been significantly reworked to improve its performance. Less data are now transmitted between the CPU and GPU and more of the work is now performed on the GPU side.

Furthermore, G-code Viewer is now able to visualize actual speed. The printer accelerates and decelerates when direction changes, so even though the required speed is set to a given value, it takes some time to reach it (if it is reached at all). The acceleration limits are (as they always were) configurable in Printer Settings -> Machine limits and PrusaSlicer always calculated with the acceleration and deceleration phases to get precise time estimate, but it did not allow to visualize them.

Note that the same disclaimers as for precise time estimates hold. If the machine limits are set incorrectly (in the sense that the printer uses different values), both the time estimate and the real speed visualization will not align with reality. Also, the actual speed visualization is not available for firmware flavors for which slicer does not allow setting the machine limits.

In addition, when moving the horizontal slider, there is a new popup dialog showing the data that G-code Viewer has about current segment, including the actual speed profile:

Single Perimeter for top and bottom layers

We have ported an option to use single perimeter for (top) solid infill layer. The feature can be configured in Print Settings -> Only one perimeter and based on the configuration, it results in single perimeter on all solid infill layers, on top solid infill layers or on topmost solid infill layers. This generally leads to improved visual look of the printed object, without sacrificing structural rigidity.

This is a frequently requested feature, which was first implemented in SuperSlicer, ported over to OrcaSlicer and then reimplemented in BambuStudio. We have ported the code from BambuStudio with only small changes. Even though we ended up not using the original SuperSlicer implementation, we would like to thank to everyone who implemented the feature there and who worked on a PR with the port (#10648), namely @supermerill, @vovodroid, @mjonuschar. Thanks also go to @bambulab for rewriting the feature later.

New system profile updating system

Since Slic3rPE 1.40 (released six years ago), PrusaSlicer has a built-in profile updater. Its task is to deliver read-only “system” profiles, which are fine tuned for the given printer and filament, sparing the user from having to tweak the individual parameters. The database of profiles has been growing ever since, and it contains many profiles, both for Prusa products and products from other vendors.

We have now split the profile database into several profile “repositories”. Profiles are updated only from repositories that PrusaSlicer is subscribed to. The repositories are selected at the beginning of the Configuration Wizard. The transition of your previous configuration requires no action on the user’s side, the repositories are automatically selected based on your currently installed profiles.

This brings the following benefits:

• Configuration Wizard loads faster, because it generally processes less data.
• Notifications informing about an existing update are only shown for your active repositories. E.g. if you only use SL1 printer, you are not disturbed by notifications about updated filament profiles, which are not relevant to you.

Offline updates

We have also covered the problem of updating system profiles on computers without internet connection. Not connecting a computer to the internet is an obvious security measure in environments where data leaks would pose a problem. However, the profile updater in PrusaSlicer relied on internet connection and there was no way of updating the profiles on such off-the-grid stations. They had to rely on undocumented and very user-unfriendly copying of configuration folders, transferring settings as config bundles, etc.

It is now possible to download a file containing the configuration update for a given repository from our website (note that the URL and the website are also in an alpha stage). This file can then be loaded as an “Offline repository”, and the configuration process treats is the same way as it would use an online update. This gives the user a possibility to update profiles by transferring this file to the off-the-grid computer on a removable drive, distribute it using a local network storage, etc.
These files can be loaded (and removed) also in the Configuration Wizard. PrusaSlicer remembers path to the loaded files and it tries to use them anytime when configuration update is triggered.

Seam improvements

Placement of seams is not a very well defined task, and it has many solutions. After the last big batch of changes in the seam placing algorithm (in 2.5.0-alpha2), the placing of seams was detrimental on various models.

In this release, the seam-placing algorithm was significantly changed to improve the results. We also did some other changes which allow the seam placing algorithm to do a better job. To name the most visible improvements:

• The ordering of perimeters was optimized to avoid unnecessary long travels between individual loops.
• To further reduce long travels, in some special cases where there are two external perimeters the seams are placed in roughly the same spot.
• The previous algorithm for aligned seams produced the seams from discontinuous “seam chains” picked heuristically on the object’s surface. Consequently, the old algorithm needed to fit a curve through the resulting seam points to achieve an aesthetically pleasing result. This worked for some models but produced worse results on others, where a strange “wiggling” appeared in places where a straight line was expected. This was particularly noticeable on very simple cylindrical models. The new seam aligning algorithm avoids this issue by employing a simpler strategy, more similar to the one used before 2.5.0-alpha2. It plans the seam from the bottom up, snapping to sharp corners. This approach generates several possible seams and selects the best one based on visibility criteria.
• One of the improvements in 2.5.0-alpha2 was the use of a seam visibility metric for seam placement. This worked well for seam hiding and the new algorithm still uses the visibility metric as the main criterion to pick the best seam possible.
• Previously, a single algorithm with different optimization criteria was used for both the aligned seam and the rear seam. This meant that the rear seam placement suffered from the same issues as the aligned seam algorithm (notably the artifacts produced by curve fitting). Another reported issue with the rear seam algorithm was that it had no notion of object center. In many use cases it is desirable that the seam is not only in the rear part of the object but also centered. Now there is a completely new separate algorithm for rear seam placement that tries to satisfy both criteria (rear and center).
• The nearest seam algorithm is now fully separated. It now simply first searches for the nearest corner to the previous position. If there is none it picks the nearest point on the perimeter.

This is a small patch release:

• Objects from 3MFs generated by BambuStudio now retain multimaterial painting when loaded
• Fixed a bug where downloading files from Printables did not work when enabled in Preferences

This is the stable release, bringing minor improvements and several bugfixes.

Improvements to multi-material printing

We implemented changes to the printing volume settings and new filament tip routines used by the MMU3 on the MK4.

Vase mode smoothing

When using spiral vase mode, the toolpaths are generated as usual and the resulting extrusions are then extruded while gradually increasing z. This approach led to seam-like artifacts on the print in places where the layer transitions would normally be. In addition, the last layer would end abruptly, creating a sharp “edge” where the extrusion ends.

Both these issues were addressed by @andrewboktor by interpolating between adjacent layers and by gradually reducing extrusion flow at the very end of the print. The improvement was recently merged into OrcaSlicer, and we got a pull request with a port to PrusaSlicer. After we evaluated the feature, we decided to merge it because it is well written, well working and very useful.

Thanks to @andrewboktor for the time and effort invested into the issue, and to both @vovodroid and @tg73 for providing a pull request with a port from OrcaSlicer

Support for 3MF files generated in BambuStudio

PrusaSlicer is now able to open 3MF files generated by BambuStudio and load geometry from them. (#10718, PR #10808, thanks to @cmguo). Please note that BambuStudio allows to save a 3MF containing G-code only, which is not supported by PrusaSlicer and loading of such 3MFs will fail.

Metadata with boundary polygon of each object

Metadata of binary G-code have a new item named objects_info, which lists all the objects in the print and their boundary polygons. The same info was added into the comments at the end of ASCII G-codes. This is useful for controlling the Cancel object feature remotely via Prusa Connect.

This is the stable release, bringing minor improvements and several bugfixes.

Improved Multi-Material Painting

We implemented several mechanisms to detect a non-valid Voronoi diagram, and by manipulating the input, we could ensure that the Voronoi diagram would be valid. We also reimplemented a significant part of multi-material painting from scratch, which, together with the changes above, should resolve all issues with spilled layers for multi-material segmentation.

Color Change (M600) Community-Driven Improvement

Previously, PrusaSlicer placed the color change (M600) right after the previous layer was finished. The default implementation of color change in pretty much all firmwares returns the nozzle to the exact same position as before the color change started. As a result of this behavior, a small blob of filament with the newly loaded color would get stuck to the print.

Our community, especially @Nohus, came up with a solution of placing the color change after moving to the next layer and position, which proved to be much easier and more universal solution than changing the M600 implementation on the firmware side. Thank you, Nohus, for your implementation and all of you who participated in testing his change.

Ramping Travel Moves: Smoother and More Efficient

We’ve replaced helical layer changes introduced in 2.7.1 with a more refined ramping profile. While the helical layer changes helped to reduce stringing, they sometimes caused color blobs and artifacts. With the new and refined ramping profile stringing is still mitigated without the disadvantages of the helical movements.

SLA Overrides

For SLA printing, we’ve introduced Material Overrides. This new feature, mirroring the flexibility of FDM slicing, allows to override selected configuration options from Print or Printer Settings in Material Settings. There is a new parameter page in Material Settings, which allows to check the parameters which would be overridden and to redefine their value.

A Farewell to Pearl

PrusaSlicer’s origin is based on the Slic3r project, which was originally written in Pearl scripting language. Over the years, we’ve rewritten nearly all of the code. First the slicing core, then the user interface. We have now rewritten all remaining unit tests still depending on Pearl into C++. Goodbye, Pearl. You will not be missed.