Creating a HATCH of points not lines

[vmax549]

Is it possible to create a hatch based on points instead of lines? Or can we create points from the dots on a hatch pattern?

The idea is to hatch an objects outer boundary with points so that we can then go back and probe only those points to create a 3d point cloud.

Thanks (;-) TP

[ger21]

No. I just looked in the help file, and a hatch is made up of lines. There is a hatch called dots, which is made up of lines with the same start and endpoints. I would use that hatch, explode it, and use a macro to convert those lines to points. I'd put the hatch on it's own layer, use layer isolate, and run the macro. I could probably whip the macro up in an hour or two this weekend, if that would work for you.

[vmax549]

THat would certainly help out a lot. I was able to create the hatch inside of a boundary shape as dots and exploded it out into entities but as you said they are really zero length lines(:-) I just could not figure a way to convert those entities into points.

This will allow us to grid out a shape boundary to allow us to probe only "inside" the boundary and not waste time probing empty space.

Thanks (;-) TP

[ger21]

Would you prefer to select the lines to convert yourself, or would you like it to autoselect them based on a layername? Or color?

This will be a very simple macro, and you'll need to use the "dots" hatch for it to work. Also, what version of AutoCAD are you using?

[ger21]

Terry, here's the macro. I did very little testing (twice), but it seems to work OK.

Hatch the area with the "dots" pattern,and explode the hatch. Run the macro and select all the lines (dots). The lines will get deleted and replaced by points. As I mentioned before, you'll probably want the hatch on it's own layer so you can isolate it, to make it easier to select.

If you want, I can change it to autoselect if they are on a specific layername. Let me know.

[ger21]

I was just thinking. Actually, you should be able to use any hatch pattern you want, since they're all made up of lines. The startpoint of each line is what gets converted into points.

EDIT:

Nope, won't work with all hatches, as some are continuous lines.

[vmax549]

Thanks Gerry I will test it and let you know how it went.

Thanks (;-) TP

[BMG]

What is the object you are hatching? Line, lightweight polyline, 3dpoly?

If its a LW pline, then a simple lisp routine would allow you to parse through the line and drop a point at chosen distances (and corners) along its length.

I have some old routines I could modify if you are not successful with Gerry's approach. Unfortunately they are at home and out of reach at the moment.

Brian

[ger21]

He wanted a "hatch" of points to fill the interior of the object. I believe he got the perimeter points by probing a part with his machine.

[BMG]

I missed that on my first reading.

Having said that, a simple point "filing polyline" routine could be created doing this as well if he does not have luck with the Hatching method.

Let me know, it would be a good exercise to refresh my lisp skills.

BMG