PrusaSlicer 2.5 is right here – new perimeter generator, STEP file assist, Lightning infill and extra!

The modifications in new variations of PrusaSlicer are normally both entire new capabilities or iterative enhancements to the present instruments. However this time, there’s a minimum of one elementary change to how the core slicing works. Such drastic modifications take a number of effort and time to develop. Fortunately, we’re not alone on this! We wish to specific our because of the whole open-source group, specifically the Ultimaker Cura staff led by Jaime van Kessel, as two main options on this launch have been initially developed by them, and to Open CASCADE for the STEP file assist. Enhancements like this are actually displaying the facility of open-source improvement.

Earlier than we go deep into what’s new, right here’s an outline of all the brand new options:

  • New perimeter generator Arachne
  • STEP file format assist
  • Lightning infill
  • Improved seam placement primarily based on the visibility
  • Strain equalizer
  • New printer and materials profiles
  • Many bugfixes and smaller enhancements


Arachne perimeter generator

For years, the technique PrusaSlicer used when producing perimeters was to offset the contour of the thing with an extrusion line of fixed width. This prompted points in numerous circumstances, particularly when printing skinny partitions, textual content, or logos.

The builders of Cura just lately applied a brand new technique named Arachne primarily based on the paper [Kuipers et al., 2020]. The Arachne generator produces perimeter loops and hole fills with various extrusion width. Merely put, it mechanically makes perimeters wider or thinner as wanted. It is a main change! Earlier than, it was almost inconceivable to create a wall that may match 2 perimeters precisely. And now? So long as the wall thickness is shut sufficient to 2 perimeters, PrusaSlicer will care for the remainder.

The brand new strategy produces nicer-looking prints with fewer artifacts. There’s a vital discount in hole fill, small extrusions used to fill gaps between perimeters, which additionally ends in a discount of print time.

Traditional perimeter generator in PrusaSlicer 2.4.2 vs Arachne perimeter generator in PrusaSlicer 2.5

One area the place the Arachne perimeter generator actually exhibits its energy is when printing texts or small logos. Drawing fonts with fixed line width is clearly fairly tough. The brand new perimeter generator doesn’t have this limitation and produces a lot cleaner texts even at a smaller scale.

Now we have determined to set the Arachne perimeter generator as the brand new default possibility. If you wish to use the previous perimeter generator, you may change to it within the Print settings – Layers and perimeters – Perimeter generator settings.

The Detect Skinny partitions function is disabled when the Arachne perimeter generator is chosen because it’s not wanted since Arachne all the time tries to adapt the extrusion width to skinny traces.

Step file format assist

Beginning with this launch, PrusaSlicer is ready to import STEP recordsdata. This CAD file format is interoperable amongst most CAD packages and it’s an ISO commonplace supported by packages akin to Fusion 360, FreeCAD, SolidWorks, Inventor, AutoCAD, CATIA, and lots of extra.

This seemingly small addition might have giant penalties. By having the ability to import STEP recordsdata instantly, we anticipate a rising variety of folks to make use of STEP when sharing the design on-line as a substitute of an STL, which is notoriously tough to edit. Alternatively, STEP recordsdata will be edited fairly simply, permitting for fast customizations and remixing. Companies that do print on demand can skip changing STEP recordsdata from the shopper to STLs, saving valuable time.

Proper now we’re tessellating the mannequin on import (changing it to a triangle mesh), so the mannequin is then sliced identical to every other mesh and never analytically. The conversion is absolutely automated (the extent of element shouldn’t be customizable). We use the Open CASCADE Know-how (OCCT) improvement platform to learn the STEP recordsdata, so massive thanks go to them for holding it open-source. It’s a CAD kernel additionally used e.g. by FreeCAD or KiCad. The import implementation itself was ported from BambuStudio, thanks go to them as effectively.

Lightning infill

Infill serves a twin goal – to supply structural rigidity and to assist prime surfaces. In case structural rigidity shouldn’t be wanted, a number of materials and printing time is saved with the brand new Lightning infill, which is optimized to assist the highest surfaces solely. The lighting infill generates a branching construction that will get progressively denser in the direction of the highest surfaces to assist them reliably.

The lighting infill is predicated on paper [Tricard et al., 2019]. Just like the Arachne perimeter generator, we have now ported the Lightning infill from Cura, thanks once more for holding Cura open supply.

PrusaSlicer already had an infill with comparable habits known as the Help cubic infill. Nonetheless, the Lightning infill saves much more materials. The next desk compares the print time and filament consumption when printing the well-known tree frog at a 400% scale.

Infill kind Print time [min] Filament complete [g] Filament infill [g] Filament saved on ifill
Gyroid 15% 1104 204 114 0%
Help Cubic 15% 792 152 62 46%
Lightning 15% 840 111 20 82%

Strain equalizer

An FDM 3D printer consists of a movement system and an extrusion system. Whereas the movement system likes to speed up and decelerate easily to cut back vibrations, the extruder likes to extrude at a continuing fee for the most effective extrusion consistency. Which means, sadly, that the optimum situations of the movement system and extruder are in battle.

Bowden-style extruders are particularly delicate to strain fluctuations, as a result of slack within the Bowden tube, they don’t seem to be in a position to reproduce fast modifications in extrusion fee reliably. The Strain equalizer smooths sudden modifications in velocity between two options (e.g. between printing infill and perimeters) and reduces print artifacts attributable to fast extruder strain fluctuations.

Earlier than shifting from a sooner inner perimeter to a slower exterior perimeter, the strain equalizer slows down steadily on the finish of the inner perimeter to succeed in the extrusion fee of the exterior perimeter. Equally, when shifting from the exterior perimeter to the infill, the beginning of the infill is slowed right down to the exterior perimeter velocity and accelerated steadily.

The print on the suitable exhibits bulges on exterior perimeters attributable to extra extruder strain on a Bowden-style printer, whereas the bulges are mitigated within the left print because of the strain equalizer

Improved seam placement primarily based on the visibility

Except you’re printing within the Spiral vase mode, every perimeter loop has to begin and finish someplace. Moreover, the printer has to cease extruding for a short second when the print head strikes as much as the following layer. This begin/endpoint creates a doubtlessly seen vertical seam on the facet of the thing.

Beginning with this model, the seam placement algorithm prefers areas that aren’t seen from the skin of the mannequin in any respect or which are occluded from most instructions. The brand new visibility algorithm is utilized for seams set to Nearest or Aligned. As well as, when paint-on seams are used and ‘Aligned’ is about, the ensuing seam line makes an attempt to discover a sharp nook within the painted space and snap to it, resulting in smoother traces alongside the sharp edge. Earlier variations didn’t detect the sharp edge on this state of affairs.

Additionally, the brand new algorithm strives to provide presumably lengthy and easy seams on easy surfaces, whereas the previous algorithm usually produced disconnected random bits on such surfaces.

For multi-material or multi-part objects the place a slice is break up into a number of areas with every area having its personal perimeter, the seams are newly hidden inside the thing between the areas.

Different new options

  • G-Code thumbnails can now be exported in JPG and QOI codecs
  • SLA hollowing is now as much as 10x sooner
  • SLA time estimate is now extra correct for the Authentic Prusa SL1S Pace
  • New and up to date third celebration printer profiles

The PrusaSlicer documentation has already been up to date to mirror many of the modifications on this launch.

For those who’d prefer to learn the total checklist of modifications, examine the changelog of every model on our GitHub. We’re specializing in shortening the event cycle, so you may get pleasure from new variations of PrusaSlicer extra usually. Because of this, some new options didn’t make it into this launch, as a result of they weren’t prepared in time, you will notice them within the subsequent model 2.6. As all the time, in case you have any questions or ideas for enhancements, don’t hesitate to share them with us. Completely satisfied printing!


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