Offset Fill Mode
Offset Fill mode works similarly to Fill Mode, but instead of telling your laser to scan parallel lines within the boundaries of a vector graphic, it tells your laser to etch lines that follow the contour of the shape.
As with both Line and Fill Mode, Speed and Power control the depth and darkness of the etch, and, as with Fill Mode, the Line Interval setting controls the spacing of the lines.
Offset Fill is intended for designs with a lot of space in between graphics, to cut down on the amount of travel time necessary to fill large, hollow shapes. If that description does not apply to your graphics, it's best to use Fill instead of Offset Fill.
Offset Fill Computation Time
Offset Fill is very computationally expensive, and the more complex the design, or the smaller the Line Interval set, the more potential there is for the computation to cause LightBurn to hang. Sometimes graphics with stray nodes or unusual paths can confuse the calculation interminably.
If you have two shapes set to the same layer, and one is inside of the other, the area between the two outlines will be filled.
Offset Fill Mode Settings¶
There are several specialized options available in the Cut Settings Editor for layers set to Offset Fill Mode, split into two tabs, Common and Advanced.
Note
See Main / Shared Settings for information on applying essential settings like Speed and Power.
See Additional Options for information on specialized settings not covered on this page.
Click any option in the images below to jump directly to the relevant section for that option, or scroll down for a list of options and descriptions.
Many of the settings presented in the images below are available for users with specific kinds of lasers, but most are shared between all types of lasers.
Right: Advanced Offset Fill Mode settings tab
Common Settings¶
Bi-directional fill, Cross-Hatch, Overscanning, and Scan Angle are presented in this tab, but are grayed out and unavailable for use with layers set to Offset Fill Mode. To use these settings, set the layer to Fill Mode.
Line Interval¶
Controls the spacing between lines, and indirectly controls Lines per Inch.
Optimizing Line Interval
Lower Line Interval values lead to a greater density of lines. The ideal Line Interval will produce lines that just touch, without overlapping.
Increasing Line Interval to the maximum amount that doesn't leave gaps between lines will lead to reduced runtimes for your projects, with no loss in quality, but you may also need to increase Power to achieve dark engravings.
Use the Interval Test or Material Test to find the optimal Line Interval for your laser and material.
Lines Per Inch¶
A different, often more intuitive way of controlling the Line Interval, or spacing between rows.
Number of Passes¶
How many times the laser will repeat the shapes on this layer. Sometimes, when cutting thick material, trying to engrave very deep, or using a lower power laser, more than one pass may be necessary.
Z Offset¶
If you have Z movement enabled, and your controller supports it, you can use the Z offset setting to move the laser head closer to the material (inward) or farther away from it (outward). Positive values move the Z Axis inward, and negative values move it outward.
Focusing deeper into the material can sometimes help to cut thicker material, and lifting the laser away from the material can produce a thicker line.
Warning for Z Moves
Z moves have the potential to physically damage your laser by crashing the head into the material.
If your system uses auto-focus, you may not be able to push the focus point lower, because most systems treat the auto-focus height as the lowest possible height (Z limit) to avoid crashing the laser head.
Z step per Pass¶
When doing more than a single pass over a shape, the Z step per pass setting allows you to tell LightBurn to raise or lower the laser with each pass by the same amount.
By allowing you to shift the focus point deeper with each pass, this is often useful for cutting thick materials or achieving deep engravings,
Fill Grouping¶
These options control which shapes are engraved at the same time by the laser. If you run your laser fast, or your laser accelerates slowly, it is often most efficient to scan things all at once, so the laser spends most of its time moving at the speed you've chosen, and less time changing direction. If you are engraving slowly, your laser accelerates fast, or the design contains a lot of blank space, it can be more efficient to fill clusters of close shapes, or to fill the shapes one by one.
Tip
If you aren't sure, try different options and use Preview to estimate the time.
- Fill all shapes at once: the default, this setting means that everything on this layer will be filled at the same time, sweeping back and forth across the whole job. If you are running the laser fast (300 mm/sec or more) this is usually the most efficient option, with some exceptions.
- Fill groups together: this setting will fill all shapes in a Group at the same time.
- Fill shapes individually: this setting fills all shapes one by one.
Advanced Settings¶
Under the Advanced tab you'll find a few less frequently-used options. The options presented here are available only for particular types of lasers.
Ramp Length and Flood Fill are presented in this tab, but are grayed out and unavailable for use with layers set to Offset Fill Mode. To use these settings, set the layer to Fill Mode.
Note
The Advanced tab is not available if you're using a Galvo laser. See Galvo-Specific Cut Settings for information on advanced settings for Galvo lasers.
Override PWM Frequency¶
If you have an RF Excited tube, this setting allows you to control the PWM frequency of the pulses sent to the laser, and can change the edge finish on certain materials.
Note
This setting is only available for lasers with Ruida controllers.
Enable PPI¶
The PPI setting (Pulses Per Inch) lets you tell the laser to send an exact number of pulses per inch of travel, instead of varying the beam power directly. This is useful for delicate materials like paper, and is similar to using Perforation Mode, but is handled by the hardware itself.
Note
This setting is only available for lasers with Trocen controllers.
U Offset¶
Enter a distance here to set a per-layer U Axis offset. To use this setting, your laser must support U Axis control, and you must enable the U Axis in Device Settings.
Note
This setting is only available for lasers with Ruida controllers.
Additional Options¶
The settings presented in the Cut Settings Editor depend on the selected Layer Mode and the type of laser you're working with. Select an option below to learn more about different groups of settings.
Note
Some options in the Cut Settings Editor are hidden if you have Beginner Mode enabled.
For more help using LightBurn, please visit our forum to talk with LightBurn staff and users, or email support.