topic Re: Hatch and Polyline in AutoCAD Forum

Hatch and Polyline

ynapeu — Sat, 12 Nov 2016 14:51:55 GMT

Hello

i have a polyline and i can hatch them when i select the object.

If i select a point inside the polyline i get an error.

If i use extruse i get a selfintersecting error message.

How can i find the selfintersecting objects?

ANd why object select works and inside point not?

Re: Hatch and Polyline

dbroad — Sat, 12 Nov 2016 15:26:27 GMT

The polyline has some errors. Selecting it allows the hpgaptol to overlook the gaps and overlaps.

To fix it, explode the polyline. Then use overkill. Then use pedit to rebuild the polyline segment by segment by using the join option. Where the polyline will not join, you have gaps or overlaps. Fix them one by one to complete the correct polyline. When rebuilding this polyline, try to avoid using the window or crossing selections as you may overlook some gaps. If the result still does not extrude, convert to a region first. Hatch may operate on the complete, closed polyline but the extrude may still have problems with it. It would be nice if AutoCAD had some self correcting features available.

Re: Hatch and Polyline

Anonymous — Sun, 13 Nov 2016 09:37:38 GMT

Dear Mr. ynapeu

Please try the command "Region" and the execute the hatch command with pick point option.

Hope this could help you

Regards

Di****h.MC

Re: Hatch and Polyline

ynapeu — Mon, 14 Nov 2016 08:21:11 GMT

Hello

i have create a region, AutoCAD will do this.

If i create the hatch with select object, it works fine.

If i create the hatch with internal Point, i get an error

and get a crazy Picture on Screen.

see Picture.

Re: Hatch and Polyline

ynapeu — Mon, 14 Nov 2016 22:54:29 GMT

Hi thanks.

Explode the Polyline, make Overkill and add each Segment with pedit.

as result i get a polyline but i can't hatch them.

Re: Hatch and Polyline

Michiel.Valcke — Tue, 15 Nov 2016 08:10:35 GMT

What is the exact error message that Autocad gives you when you try this.

From the top of my head there are a few things I can think off that might or might not be the cause of this behaviour.

- Is you Polyline closed?
- Is the elevation set to 0?

- Is the shape of your polyline very complicated (with a lot of vertexes) or does it consist of basic shapes?

...

Re: Hatch and Polyline

dbroad — Tue, 15 Nov 2016 12:56:16 GMT

After explode and overkill, rebuild the polyline segment by segment using pedit's join option. You might be able to window select or crossing select but do not use the close option. Afterwards, you should see that you do not have a single polyline. You might have 2 or 3 polylines. At the end of each polyline endpoint zoom in very very closely to the endpoint of the polyline. Microscopically, you can see either gaps or overlaps. Grip select the endpoint of the segment to change and stretch it to coincide with the endpoint you want to keep. Repeat the process of joining via pedit until you have a correctly constructed, closed polyline. Then it will be hatchable. If you draw it correctly, via this process, you will be able to pick the point in the center and it will hatch.

Re: Hatch and Polyline

ynapeu — Wed, 16 Nov 2016 08:44:10 GMT

Hello

you are right in a lot off Points.

i have explode the polyline, i have used overkill.

Than i use pedit, i only get 2 Polylines.

Now i modified the endpoint.

create a new polyline all objects are added.

if i will hatch i get the same error.

i have written some objectarx code.

but there are some Problems.

if i use the internal

getLineSegAt and getArcSegAt

then i compared start and endpoints.a get small gaps.(see file polylinedata_original.txt)

if i use explode and compared the data every distance ist 0.(see file polylinedata_explode.txt)

i also added the new drawing.

you can explode them and use pedit the will add objects.

Re: Hatch and Polyline

dbroad — Wed, 16 Nov 2016 16:28:38 GMT

Whenever lines and arcs are connected, they should be connected will the fillet command to ensure tangency. Many of your arcs have odd or inaccurate radii. If lines and arcs are joined without fixing the underlying overlap problem, you get confusion by hatch, boundary and extrude. I recommend that you change your visual style to 2d, flatten, explode, and overkill. Make sure you are in the top view. Increase your viewres and units accuracy. Then replace all of the arcs with correctly filleted geometry. The alternative, which may or may not work is to delete all the lines and using the osnap end option redraw all of the lines connecting arcs. Unfortunately, there are still arc to reverse arc pairs that may overlap or be non-tangential.

See screencast. Bottom line: Draft accurately and AutoCAD will work properly. Draft poorly and everything will be difficult.