topic Re: problem in sorting stripe hatches in ATU in Netfabb Forum

problem in sorting stripe hatches in ATU

rasouliprs — Mon, 14 Oct 2024 05:56:51 GMT

Hi everyone,

I recently decided to use the Stripe method to hatch a part in ATU. I have some limitations for using this method:

-Stripe boundaries and hatches should rotate 60 degrees in each layer (stripe and their hatches should be perpendicular to each other).

-Hatches always should be started from "bottom to top" of the part

To reach these goals, after rotating stripes and their hatches, I have used sorting methods (Bottom to Top) with the function "SORT_UTIL.nSortMinDistToSegmentsMethod_NearestSegments" with "PerpendicularMeander" filling mode. But in some layers, instead of hatching from bottom to top, I see some jumps like the picture. How can I solve this problem?

Regards,

Parmida

Re: problem in sorting stripe hatches in ATU

robert.weitzel — Mon, 14 Oct 2024 08:17:20 GMT

Hello Parmida, could you please attach the picture you are referring to?

Re: problem in sorting stripe hatches in ATU

rasouliprs — Mon, 14 Oct 2024 08:19:38 GMT

Hi Robert,

Sorry to forget. So now here is the picture.

Thanks,

Re: problem in sorting stripe hatches in ATU

robert.weitzel — Mon, 14 Oct 2024 12:02:47 GMT

You should use the function createStripesExt():
- Use fStripeAngle in the range of 0 to 180, or maybe 10 to 170 so that each stripe is going upwards.
- Set bStripeOrderLeft=true for angles < 90 and bStripeOrderLeft=false for angles > 90.

Re: problem in sorting stripe hatches in ATU

rasouliprs — Sat, 19 Oct 2024 08:58:51 GMT

I appreciate your help, Robert.

I did what you said and the jumping problem was successfully fixed, but by forcing the stripes from left to right and vice versa, in some parts, I guess it could not guarantee to hatch from bottom to top of the part, like the picture that I have attached here. So, what can I do for these parts?

Many thanks for your support.

Parmida

@robert.weitzel

Re: problem in sorting stripe hatches in ATU

robert.weitzel — Wed, 23 Oct 2024 06:35:40 GMT

To mitigate this problem you can limit the length of each stripe and then sort the resulting hatch blocks from bottom to top:

1. Limit stripe length (e.g. 20mm):
Use bsIsland.createStripesExt function with fStripeLength=20.
(Controlling the stripe angle and stripe order as mentioned above will still be necessary to have the hatches within each hatch block in the upward direction)

2. Sort the hatch blocks from bottom to top:
In your postprocessLayerStack function do the following for each layer:

let exposure_array = modelData.getLayerPolylineArray(layer_nr, POLY_IT.nLayerExposure, "rw");

exposure_array.sort(function(a,b){
let boundsA = a.getBounds2D();
let boundsB = b.getBounds2D();

// sort by minY
if(Math.abs(boundsA.minY - boundsB.minY) > 1)
{
return boundsA.minY - boundsB.minY;
}

// a and b are roughly on the same Y
// -> sort by minX
return boundsA.minX - boundsB.minX;
});

// Overwrite the "processing order"
for(let i=0; i < exposure_array.length; ++i)
{
exposure_array[i].setAttributeInt('_processing_order', i+1);
}

Instead of sorting by bounds minimum you could also sort by bounds center or whatever fits your requirements.

Re: problem in sorting stripe hatches in ATU

rasouliprs — Wed, 06 Nov 2024 08:46:18 GMT

Dear Robert,

I have followed the steps you said and it seems that it works! Except for some geometries such as a cylindrical area. because minimum y is in the middle of the part, it is better to scan from left to right and vice versa ( in some stripes angle!)

Another exception is for example a cube. Where all y s are the same. Based on the angle of the stripes, min x is not always the right side or left side of the part.

However, I believe that by knowing these rules, I can choose which one is better for different geometries.

I have attached some pictures to clarify the problems in the example geometries.

Thank you very much for your valuable guidance and support.

Regards,

Parmida

Re: problem in sorting stripe hatches in ATU

rasouliprs — Wed, 06 Nov 2024 08:48:24 GMT