Layer height, adaptive layers and anti-aliasing

Before you start

You need a printer and a resin chosen on the plate (Your first print). Have the layer height and exposure your resin’s maker gives for your printer. Every number below is a starting point for one printer and one resin, not a recommendation: the maker’s and the printer’s instructions come first, and a calibration print comes before a real one. Resin safety is covered by the maker’s safety data sheet.

Open the Layers panel

Pick the Layers and exposure tool on the tool rail, or press 7. The panel is headed “Layers”. From top to bottom it holds Layer height, Planes a layer, Anti-aliased masks, Adaptive height and Exposure by height. Exposure by height has its own guide, on exposure.

Set the layer height

Type the height in Layer height, in millimetres. The field takes 0.01 to 1 mm. A shipped resin opens at its own height: Standard grey on the Saturn 4 Ultra, for example, at 0.05 mm.

Change it and Encrust rescales the exposure to match, with a line under the field: “Exposure carried with the layer: 2.30 s at 0.050 mm is … s now.” A Back button next to it restores the old value. The scaling is exponential, not linear, and assumes a penetration depth of 0.10 mm. A resin measured at 0.05 mm for 2.7 s is written at about 4.45 s at 0.1 mm, and going from 0.1 to 0.05 mm keeps about 61%, not half. That depth is an assumption. The bottom block is not rescaled. Check the new exposure against what your maker gives for that height, and print a calibration piece before a real one.

What the height buys you is arithmetic. A layer leaves a stair step of height times the cosine of the slope: nothing on a vertical wall, the whole layer on a flat face. At 0.05 mm, a 30 degree slope steps 0.043 mm. Doubling the height halves the layer count and doubles the stair step on a slope.

Leave Anti-aliased masks on

Anti-aliased masks is on by default. Encrust then gives each edge pixel the grey that matches the exact share of it the layer covers, so a wall at a fraction of a pixel prints as a fraction of a pixel. Off, a pixel is lit when its centre falls inside the part. With it on, the panel shows two more settings.

Round the grey to levels

Round edge grey is off by default, which keeps every grey from 1 to 255. Switch it on and Grey levels appears, from 2 to 16, starting at 8. Encrust rounds each edge grey to a ladder of that many steps. At 8 levels the rungs are 31, 63, 95 and so on up to 255, common ladder values.

Fewer levels mean fewer different greys on an edge, and a smaller file, because each grey pixel breaks a run of black or white. Which levels your panel and resin cure we haven’t measured.

File formats differ in how much grey they hold. The command-line notes list a .cbddlp as carrying eight times the layer data, an Anycubic file as losing edge greys dimmer than 16, and an .svgx as holding none.

Set the edge blur

Edge blur is a radius in pixels, 0 to 8, and 0 by default. Encrust averages the coverage over a box 2 times the radius plus 1 pixels wide, across then down, before the greys are rounded. At a radius of 1, the pixels either side of a straight edge read a third and two thirds, and half of the fade lies inside the part.

Above 2 pixels the panel warns that a wide blur dims the wall inside the edge as well. The cost is file size and time. On one 1632-layer test model, radius 1 raised a 45 MB file to 73 MB, and radius 2 to 101 MB, with the floor at its older default of 128. Start at 0 and raise it only if a print shows a problem.

Set the grey floor if an edge stays liquid

The Grey floor is a printer setting, not a slicing one. Open Settings (Cmd+, or Ctrl+,), select your printer in the Machines list, and find it in the Display card, below the pixel pitch. It runs 0 to 254 and every profile ships at 0, so every grey is written.

A pixel dimmer than the floor is written black. Set it if a thin wall comes out with liquid resin behind it: a pixel too dim to cure leaves it liquid, and the floor trades a fraction of a pixel at every edge for that. Raise it in steps, slicing and printing a calibration piece each time. We have no measured floor for any printer.

Add planes for features thinner than a layer

Planes a layer, 1 to 5 and 1 by default, samples that many planes inside each layer instead of the middle one, and takes the brightest pixel of them. A fin, a thin rib or the tip of a cone that falls between layers then survives. Encrust combines the planes by brightness rather than by adding them, so a wall’s anti-aliased edge keeps its grey.

It costs work in proportion, though not always time: a 14,400-triangle sphere in 400 layers took 0.43 s at one plane and 0.45 s at five on eight cores. The volume in the estimate misses what only an extra plane found. The figure written in the file’s header does not.

Try adaptive height against a cusp target

Adaptive height is a switch named “Against a cusp target”. On a shipped printer profile it is greyed out, with the note “This printer steps the plate by the header’s height, so no layer can have one of its own.” No shipped profile claims variable layer height: we could not confirm that firmware obeys per-layer heights, so no shipped profile claims it. A printer that ignores a layer’s own height prints an adaptive stack at the wrong scale without saying so.

If you have tested your printer with mixed layer heights, open Settings, find the Firmware card for it and switch on Variable layer height. Then the Adaptive height switch works. We have no printer on which this is confirmed.

With it on, Layer height is renamed “Thickest layer” and becomes the ceiling: whatever you type there is the thickest layer Encrust will cut, and it replaces the 0.10 mm the adaptive settings start from. Two more fields appear:

Field	Default	Meaning
Cusp	0.01 mm	the stair step you accept on a surface
Thinnest layer	0.02 mm	the floor; every layer is a whole number of it

Encrust reads each face’s normal. A vertical wall takes the thickest layer. A slope takes the thickest layer whose stair step stays under the cusp, rounded down to a whole number of thin layers. At the defaults, a 45 degree slope would need 0.014 mm and gets 0.02 mm. A wall 10 degrees off vertical allows 0.058 mm and gets 0.04 mm. That is arithmetic from the formula, not a measurement. A flat face gets a layer boundary on itself.

A thickest layer that isn’t a whole number of the thinnest is never reached: 0.05 mm over a 0.023 mm floor tops out at 0.046 mm, and a note under the field says so and gives the exposure for it. Each layer is exposed for its own thickness. The bottom block is not.

Adaptive height is a quality setting, not a speed one. On a sphere at a 0.03 mm cusp it gave more layers than a uniform 0.1 mm stack, because the poles are shallow. It saves layers only on mostly vertical parts. A face within a thousandth of horizontal counts as flat; a model tilted one degree gets none of the benefit. A coarse STL of a curved surface plans to its facets. An .sl1 file refuses an adaptive stack.

If something goes wrong

The Adaptive height switch is greyed out

The printer’s profile doesn’t claim variable layer height. “Open printer settings” takes you to the Firmware card. Switch it on only for a printer you have tested.

The exposure changed when I changed the layer height

That is the carried exposure. Press Back next to the note to restore it, or set the exposure by hand. Check it against what your maker gives for that height.

Thin walls come out soft or with liquid behind them

Raise the Grey floor in steps, or set Edge blur back to 0 and Round edge grey off. A wide blur dims the wall inside the edge.