Merging layers - what needs to be updated afterwards?

[b005t3r]

I'm writing a script which merges, for instance, 10um layers into z single 30um layer, which means I need to remove some layers in the process with:

SlicerFile.RemoveAt(layerIndex);

After doing the merging and deleting, I need to update the layer height for layers, bottom layers and transition layer (anything else maybe?). My question is: what exactly do I need to update and how do I do that?

I'm currently doing this:

        SlicerFile.LayerHeight *= sublayerCount;
        SlicerFile.BottomLayersHeight *= sublayerCount;

(i.e. if I merge 3 layers into a single layer, my sublayerCount is set to 3);

I'm pretty sure there's something missing here, because UVTools reports a negative printing time for the transition layers (10um layers merged into 30um layers):

Before runningthe script (10um layer height):

The same file, but exported at 30um:

Also the print height is reported incorrectly

Before merging (10um layers):

After merging (30um layers):

[b005t3r]

Also, here's a small example of what I'm trying to achieve:

Input file (10um layer height):

Layer14
Layer13
Layer12
Layer11
Layer10
Layer09
Layer08
Layer07
Layer06
Layer05
Layer04
Layer03
Layer02
Layer01
Layer00

Output file (30um, some layers removed):

Layer14 (merged with Layer13, Layer12) 
Layer11 (merged with Layer10, Layer09)
Layer08 (merged with Layer07, Layer06)
Layer05 (merged with Layer04, Layer03)
Layer02 (merged with Layer01, Layer00)

In this example I want each layer to be 3x thicker, the number of bottom layers, transition layers, exposure times, etc. should NOT change. The idea is to simply export from the slicer software with all settings dialed in to a given layers height (let's say 30um), but setting the actual slicing height to something lower (10um), effectively exporting at a higher precision; then merge everything in UVTools to have that sub-layer data baked in the thicker layers.

[b005t3r]

I figured out I can actually do it like that:

        var allLayers = SlicerFile.Layers.ToList();
// modify allLayers however I want
        SlicerFile.LayerHeight *= sublayerCount;
        SlicerFile.BottomLayersHeight *= sublayerCount;
        SlicerFile.Layers = allLayers.ToArray();

I think that solves it, but I'd love to hear a confirmation on this one from you @sn4k3 :)

[sn4k3]

There are some variables you need to tune as well supression might be required.
UVtools have this implemented in two tools:

1. Dynamic layer height (Complex)
2. Adjust layer height (Matches your script, it will merge or multiple layers but keep same total height)

Study the 2. at if (_method == OperationLayerReHeightMethod.ReHeight) branch which matches your script strategy.

There you will also find the "correct" way to set the layers and properties with supression:

SlicerFile.SuppressRebuildPropertiesWork(() =>
{
    SlicerFile.LayerHeight = (float)_selectedItem!.LayerHeight;
    SlicerFile.BottomExposureTime = (float) _bottomExposure;
    SlicerFile.ExposureTime = (float) _normalExposure;
    SlicerFile.Layers = layers;
}, true);

Note the first true will reset layer properties with the global values but un-touch PositionZ, if you pass a 2nd true the layer PositionZ will be reset with LayerHeight * LayerNumber

[b005t3r]

Thanks!

I modified my code like that:

        SlicerFile.SuppressRebuildPropertiesWork(() =>
        {
            SlicerFile.LayerHeight *= sublayerCount;
            SlicerFile.BottomLayersHeight *= sublayerCount;
            SlicerFile.Layers = allLayers.ToArray();
        }, true, true);

So the layer height is increased (for example, if the file was sliced at 10 µm and I want to print at 30 µm, I run the script for 3 sublayers), the number of bottom layers remains the same as in the 10 µm file (let’s say I had 5 bottom layers at 10 µm, totaling 50 µm — I still want to have 5 bottom layers at 30 µm, so the total height should be 150 µm, which means multiplying the height by 3), and the rest is based on your example. Is that correct, or am I still missing something?

[sn4k3]

Looks fine, it will work as long your input slices are in 10um.