PrusaSlicer 2.4.0-alpha1

PrusaSlicer PrusaSlicer 2.4.0-alpha1

Summary

This is the first alpha release of PrusaSlicer 2.4.0, introducing Multi-material painting tool, improved FDM supports and raft, Windows dark mode, Fuzzy Skin, per object Brim configuration, Negative volumes, automatic Color Print for signs, Shape Gallery, "Tip of the day" notifications, Model simplification, support for Marlin 2 acceleration control, support of 3DLabPrint airplane models, new 3rd party printer profiles and many more new features, improvements and bugfixes.

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

The software is based on work of Alessandro Ranelucci (@alranel ↗) and the RepRap community. The first public commit ↗ is from 2011-09-01, meaning that exactly today, PrusaSlicer based on Slic3r celebrates its tenth birthday🎂🍾 Thanks to all who contributed during the decade and helped to continuously improve the software.

Complete description of improvements and changes with respect to the current PrusaSlicer 2.3.3 release ↗ follows.

Multi material painting #3535 ↗

In PrusaSlicer 2.3.0 we have introduced paint-on supports and seams. Seeing the painting tools in PrusaSlicer, many customers asked for similar tools to help with multi material printing. Indeed, preparing models for multi material FDM prints used to be a laborious and time consuming process. With this release of PrusaSlicer, that is a thing of the past and coloring an object for multi material printing requires just a handful of bucket fill and brush stroke operations.

mmpaintingjpg

The editing tool opens with N hot key and it offers the following tools:

1. Brush: similar to the old support or seam painting tool.
2. Smart fill: fills a region below the mouse cursor up to a sharp edge (the sharp edge threshold is adjustable at the panel).
3. Bucket fill: replace a patch of one color with another.

mmu_painting

Combo boxes in the panel allow mapping different extruders to left and right mouse button. The number and color of the selected extruder is shown for clarity. The color that is used for visualization can be overridden by clicking the colored square next to the selected extruder. This visualization color is not saved anywhere and will be lost when the application closes.

Once the object is painted, the object surface is segmented into patches of same material and the patches are extended inwards. The regions painted at the top resp. bottom surfaces are extended by the number of topsolidlayers resp. bottomsolidlayers (configurable in Print Settings->Layers and Perimeters). The regions painted at the side walls are expanded inwards up to maximum mmusegmentedregionmaxwidth (which is a new configuration parameter accessible in Print Settings->Multiple Extruders->Advanced).

The painting only affects the slicing result, the model itself is not altered and the colored "parts" cannot be exported separately.

Notes

Please note that thin features are not printable with FDM technolgy, thus for example painting a thin wall with two distinct colors will not make the thin wall printable. Such thin non-printable regions created during segmentation are thus detected and merged with the neighboring region, changing its color. PrusaSlicer will print thinner features with "detect thin walls" enabled, thus one is advised to try to enable "detect thin walls" if painting over thin features.

There are two extra limitations arising from technical reasons:

• The multi material painting is limited to 16 extruders. If your printer uses more extruders, only the first 16 will be available in the painting tool.
• Multi material painting cannot be combined with XY size compensation. The XY size compensation will be ignored during slicing if the object is also multi material painted.

The user is informed by a notification in both cases.

Bottom layers bridges

PrusaSlicer is based on the pioneering work of Alessandro Ranelucci and the RepRap community on the Slic3r project. As already mentioned above, the project was started ten years ago and a lot has changed since then indeed. The 3D printers are no more a rarity, ABS is not the only filament, motion systems are accurate and extruders are no more leaky. Thus adjustments to the slicing algorithms are called for.

Slic3r's strategies of FDM supports and object over support differ from the other FDM slicers. Namely, Slic3r was designed to make use of FDM bridging capabilities to circumvent the necessity of supports. And printing bridges with ABS was not that easy: The bridges were reliable only if extruding thick strands. Combining the thick bridges with supports required the 1st layer objects being printed thicker than the other layers, leading to ugly object undersides.

All the other FDM slicers evolved differently: The first layer over supports is printed with the same flow as the other layers, thus the first layer over supports looks nicer as long as the strands bridged reliably or supported by a support interface. For support materials that do not bridge reliably, dense support is required for high quality of objects over supports.