path: root/resources/texts/change_log.txt

[Arachne engine second beta]

<h1>Arachne engine beta 2</h1>
Our new Ultimaker Cura engine allows you to create parts with ground-breaking quality, strength, and speed. This is made possible by fundamentally redefining how the inside of a model is generated – through adaptive line widths and optimized line positioning. <br>
Earlier this year, we released the first beta of Ultimaker Cura Arachne engine. Which received an overwhelmingly positive response, thank you for all your feedback! 
Since the first beta release we've been working on improving the Arachne engine. <br>
Join <a href="https://github.com/Ultimaker/Cura/discussions/10931">our discussion</a> on GitHub to provide us with all your feedback.

* Back pressure compensation
Print quality is improved through dynamically adjusting print head velocity, which slows down or speeds up depending on the pressure of the material through the Bowden tube.

* Printing order filling gaps
Gaps in models are now filled in after placing the outer wall, resulting in less over-extrusion.

* Print quality enhancements
All print quality improvements from Ultimaker Cura 4.12 have been added.

* New settings:
- Split Middle Line Threshold
- Add Middle Line Threshold
- Expose the Distribution radius of the Inward Distributed strategy

* Bug fixes:
- Fixed a bug with concentric skin lines
- Fixed memory usage, contributed by Piezoid
- Fixed a bug with opening old project files in Arachne
- Fixed a bug where the width was not adjusted
- Fixed a bug with Line Compactness behaviour was inversed for Central Deviation
- Fixed a bug with tiny movements which caused a nozzle slowdown
- Fixed a bug where blobs in g-code were generated
- Fixed a bug with Minimum Wall Line Width setting was used if Print Thin Walls was disabled
- Fixed a bug where the Inner Line Width was wider thatn the end of the model
- Fixed a bug where Maximum Resolution was not applied for hyperbolic arcs in inner walls
- Fixed a bug where Combing was broken
- Fixed a engine crash within the inset order optimizer with 3 walls, contributed by Piezoid
- Fixed a bug where the Seam placement was not on the correct corner
- Fixed a bug where the centerline of Central Deviation is not generated
- Fixed a bug with Bottom Skin Expand Distance at zero caused skin to expand beyond walls

* Known issues:
- Gaps in inner wall where it has enough space to print one line
- Unwanted travel moves when monotonic order in enabled
- Printer pauses at certain layer creating dripping spots
- Retracted unnecessary travel moves

*<i>Note: This is _not_ based on a specific stable version of the front-end of Cura (like '4.12.0' or similar), so there may be issues that have been solved or introduced since then that have little or nothing to do with the variable line width feature-set!</i>

<h1>Arachne engine beta 1 </h1>
This is the beta release of Ultimaker Cura's "Arachne" engine. The objective is to fill the available space better with walls, reduce variability in flow rate, preventing gaps and overextrusion and improving path planning by implementing variable line widths. This allows for a more consistent print and better fit to the specifications of the original 3D model.
If you've tried this beta and want to give some feedback, please see the discussion here.
This is a second preview, bringing the engine to a more stable state than the alpha that was released in December. This release should be more appropriate to tune profiles within preparation for the stable release. The stable release will still have its own beta in the same fashion as the ordinary release cycle.
While the bugs and features that greatly influence print quality have been resolved and implemented, there are still some things left to do (see known issues). The profiles have hardly been tuned, even for Ultimaker's own printers. Please don't expect perfection. In fact, the default settings as they are now likely result in a worse print quality than the stable release.
Note: This is _not_ based on a specific stable version of the front-end of Cura (like '4.8.0' or similar), so there may be issues that have been solved or introduced since then that have little or nothing to do with the variable line width feature-set!

* New features in Arachne engine beta:

* Line Width Color Scheme
A new color scheme has been added that shows the line width of individual lines in layer view.

* Static Outer Wall
The outer wall will no longer adjust its width or position if there are any inner walls adjacent to it with the (inward) distributed line width strategy. This reduces ringing effects in thin shapes.

* Bug fixes
- The Randomize Infill Start setting is now working on Arachne.
- The Infill Travel Optimization setting is now working on Arachne.
- The Infill Layer Thickness and Support Layer Thickness is now working on Arachne.
- Fix crash on MacOS when printing parts with a single wall.
- Fix crash when the model contains very small holes (~0.1mm).
- Fix crash when using Support Infill.
- Fix crash when the model contains faces that are almost exactly parallel.
- Fix crash when simplifying due to Maximum Resolution causes self-intersections to appear in the layer outline.
- Fix crash when multiple transitions come together in the same point.
- Fix crash when transitions between different numbers of walls connect the wrong two perimeters together.
- Infill and support layer thickness should no longer overlap with itself if gradual infill or gradual support is used.
- Only generate connecting wall segments for the sparsest density when using gradual infill or gradual support.
- Sharp corners in the infill volume will no longer be filled with a useless tiny infill line.
- Initial Layer Line Width now only applies to the initial layer again.
- When using Outer Wall Inset, there will no longer be a ridge when transitioning from 2 to 1 wall.
- Outer Wall Wipe Distance will no longer cause unnecessary travel moves.
- Concentric support interface patterns are no longer omitted.
- When Wall Line Count is 0, the rest of the model will no longer be omitted.
- When using different extruders for inner and outer walls, the extruders no longer alternate per layer.
- Small gaps between inner wall and skin are properly filled with infill again.
- Seam position when using Sharpest Corner set to "hide seam" now properly chooses the sharpest inner corner.
- Transitions are no longer omitted in very sharp corners, which sometimes led to too small line widths.
- The outline of the print is no longer shifted towards the bottom left by the Maximum Deviation setting.
- When using Alternate Extra Wall, the extra wall no longer overlaps with skin or infill.

* Known issues
- Some models might still crash the engine, although it is less frequent then before.
- Infill support can crash the engine.
- The seam isn't positioned correctly when using the Hide or Expose or Smart Hiding placement options.
- User specified seam is not aligned.
- Paths for concentric ironing aren't generated.
- Concentric support pattern can intersects with model.
- Lines are not always symmetrical in width at the transitioning point to a lower wall count.
- Center line is not generated for centre deviation strategy.
- Missing infill/support walls in certain areas when using Extra Infill/Support Wall Count.
- Brim lines ordered wrongly.
- Raft interface layers and raft layers don't align.
- Connected infill and gradual infill results in overextrusion.
- Bottom Skin Expand Distance at zero causes skin to expand beyond walls.
- Spiralize could generate both inner and outer surfaces.
- Bottom layers of a spiralized model with surface mode enabled, looks like inner walls.
- Last bottom layer might disappear for a spiralized model.
- Stringing when spiralized is enabled.
- Fuzzy skin isn't implemented.
- Connect Top/Bottom polygons isn't implemented.

<h1>Arachne engine alpha</h1>

The Cura Team, as part of and with help from Ultimaker R&D in a more general sense, have been working on a large project that changes the core of how our slicing engine works.
The goal is to have variable line widths (instead of static) for each extrusion, and better path-planning, in order to better fit the eventual printed part to the specifications.
If after you've used this alpha you want to give some feedback (please do, it's the main reason we're doing this), please see the discussion here.
This effort is still ongoing, but we're at the point where we would very much like to have the feedback and input of the wider community.
In order to get this done, we've decided to release an 'Alpha' build, or an early preview.
Not everything has been implemented, and there are even an amount of known bugs (see below), as well as very probably a comparable amount of unknown issues.
On top of that, we added some parameters (and removed a few others). These have hardly been tuned, even for our own printers, let alone 3rd party ones.
In other words, don't expect perfection. In fact, the default settings as they are now are likely to be worse as what's there in a lot of cases.
Note: This is _not_ otherwise build on a specific version (like '4.8.0' or similar), so there may be issues that have been solved or introduced since then that have little or nothing to do with the Variable Line Width feature-set!

* New Settings
Variable Line Strategy: How the walls are spread over the available space.
- Central Deviation: Will print all walls at the nominal line width except the central one(s), causing big variations in the center but very consistent outsides.
- Distributed: Distributes the width variations equally over all walls.
- Inward Distributed: Is a balance between the other two, distributing the changes in width over all walls but keeping the walls on the outside slightly more consistent.
- Minimum Variable Line Width: The smallest line width, as a factor of the normal line width, beyond which it will choose to use fewer, but wider lines to fill the available space. Reduce this threshold to use more, thinner lines. Increase to use fewer, wider lines.
- Wall Transition Length: When transitioning between different numbers of walls as the part becomes thinner, a certain amount of space is allotted to split or join the wall lines.
- Wall Transition Angle: When transitioning between different numbers of walls as the part becomes thinner, two adjacent walls will join together at this angle. This can make the walls come together faster than what the Wall Transition Length indicates, filling the space better.
- Wall Transition Filter Distance: If it would be transitioning back and forth between different numbers of walls in quick succession, don't transition at all. Remove transitions if they are closer together than this distance.
- Maximum Extrusion Area Deviation: Influences extrusion line simplification. The maximum extrusion area deviation allowed when removing intermediate points from a straight line. Keeping it low may cause (too) little simplification to occur (with all the problems that causes), but if you increase this you may notice slight under- (or over-) extrusion in between straight parallel walls.

* Removed/Renamed/Altered Settings
- Print Thin Walls: Behaviour altered.
- Optimize Wall Printing Order is renamed to Order Inner Walls By Inset. Behaviour altered.

* To Implement
Not all initially planned sub-features are in yet, any subsequent non-patch releases will probably contain more.

* Known Issues:
- SkeletalTrapezoidation not robust to unsimplified input. For very intricate and or small models, crashes may occur. Please attach any crashing model to the discussion/feedback link above.
- Different extruders for inner and outer walls. The used extruder alternate each layer but the inner and outer wall are printed with the same extruder (used at that layer)

* Spiralize bugs:
- Bottom layers issue in spiralize mode.
- Stringing when in spiralized mode.
- Last bottom layer missing for some models.
- Support not being correctly generated. It might start mid-air or not providing enough support for some parts of the model.
- Gradual infill support not being correctly generated. Support walls don't seem to be printed well when gradual infill support is enabled. Ultimaker printers enable this by default for PVA.
- Combing in the wrong part when printing dual extrusion Visible, for example, when printing with dual extrusion with two different colors. E.g.: 'Bleeding' of red into white parts.
- Printed travel moves.
- Gaps between inner wall and skin.
- Z-Seam Sharpest Corner broken. The seam is not placed in the sharpest corner
- Small line width and overlap. When using the Center Deviation setting on a thin model some wall lines may overlap or leave a gap.
- Wall positioning is imprecise. On some models, the walls are not centered properly within the outline nor have the correct width.
- Connected and gradual infill results in overextrusion. When gradual infill and connect infill lines is enabled, it'll connect different pieces of infill on top of each other, causing overextrusion.
- Connect Top/Bottom polygon not working currently. The issue occurs when concentric is the infill pattern.
- Small travel line segments in infill/support. This is causing unnecessary traveling and stringing.
- Wrong Infill Layer Thickness. In combination with a higher Extra Infill Line Count, some parts are not generating infill lines.
- Inward/Distributed overextrusion. Seen on models with multiplied infill walls.
- Overlapping skin and alternating wall. The extra wall at each alternating step will overlap with the skin
- Assertion failure in SkeletalTrapezoidation. Can cause the engine to crash on certain models.