Painting Failures in Valleys and Low Slopes

[Flyingvette]

Description of the bug

Experiencing failures of the painting functionality related to the depth of color changes in prusa slicer under the following two conditons:

1. Narrow gaps
2. Top layers of shallow slopes

Narrow gap, painted view:

Narrow gap, gcode preview:

Expected behavior is for the slicer to extend the area of color beyond the edges of the vertical intrusion of the models to ensure the color is put down appropriately as painted. This can be resolved by forcing a minimum width for color changes that extends into the infill areas when there is a valley or narrow gap with color added.

Shallow slope, painted view:

Shallow slope, gcode view showing infill bleedthrough (grey in screenshot):

Expected behavior is for the 2-3 layers below the color layer to carry the same color, rather than defaulting to the infill color. This often leads to color bleed through, small example below:

This is a long standing issue for myself and other users. Although it mitigatable when the original cad / modeling file is available via object splitting, this is not a common practice for stl files provided both for free and commercially.

Project file & How to reproduce

paint valley and infill fail.zip

Checklist of files included above

• Project file
• Screenshot

Version of PrusaSlicer

2.8.0

Operating system

win 11

Printer model

Prusa XL5