Hatches...

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Caddy
Posts: 40
Joined: Tue May 19, 2015 6:35 pm

Hatches...

Post by Caddy » Fri Jun 05, 2015 8:05 am

Bonjour Eric

Please look yourself what happened.
The most left hatches (top-right to bottom-left) with the setting 45-6-0-0,25 seem to be ok.
The other 2 hatches (top-left to bottom-right) with the same setting but a negative angel (-45°) didn’t work properly, the upper one … ok… but the lower one it’s far away from beeing ok. Please check.

Hubert
Attachments
Hatches 01.png
Hatches 01.png (10.79 KiB) Viewed 3937 times

debenriver
Posts: 442
Joined: Sat Dec 03, 2011 9:19 pm
Location: Maine USA and Suffolk England
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Re: Hatches...

Post by debenriver » Fri Jun 05, 2015 10:43 am

Hi Hubert

It looks as if the two rectangles that you are hatching are incomplete areas. Or you have other bits of unjoined lines left from construction. When that happens, just draw a rectangle, using snap, hatch it and then delete the rectangle. The little rectangles can be coloured white and brought to the front.

Or, better, just trace over the outline using snap, hatch, and remove the trace polygon, leaving the hatch.

George

Caddy
Posts: 40
Joined: Tue May 19, 2015 6:35 pm

Re: Hatches...

Post by Caddy » Fri Jun 05, 2015 11:28 am

debenriver wrote:Hi Hubert

It looks as if the two rectangles that you are hatching are incomplete areas. Or you have other bits of unjoined lines left from construction. When that happens, just draw a rectangle, using snap, hatch it and then delete the rectangle. The little rectangles can be coloured white and brought to the front.

Or, better, just trace over the outline using snap, hatch, and remove the trace polygon, leaving the hatch.

George
Hi George

It isn't so like you've mentioned. I've tried to make some investigations. First I made a copy from the original and drag the copy somewhere to a free space, nothing behind and nothing above. I'd tried to make the enclosing rectangle at the small side a little bit bigger. This works! If I come back to the old shape, I got the same as before. I'd looked already for each point using the Edit panel and every point including dx/dy looks alright. The original shape was drawn using the polygon tool in one session.

Hubert

Eric Pousse
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Location: Tours - France

Re: Hatches...

Post by Eric Pousse » Fri Jun 05, 2015 11:38 am

Hubert,

I noticed that in some cases this problem occurs when vertical or horizontal lines are not exactly vertical or horizontal.
When you edit each segment of the polygon you have probably some dx or dy which are -0.0
If you change them to 0, the hatch will work.
Eric Pousse

debenriver
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Re: Hatches...

Post by debenriver » Fri Jun 05, 2015 11:46 am

Good morning Hubert!

That is pretty strange – I've found RealCADD to be 100% good at hatching closed shapes and it makes a pretty good stab at unenclosed shapes, overlapping shapes etc..

In the sketch below the lines are not made into polygons – they are just selected and hatched.
Screen Shot 2015-06-05 at 07.36.50.png
Screen Shot 2015-06-05 at 07.36.50.png (11.33 KiB) Viewed 3930 times
But the ends of the lines have to be joined (snap E) or if elongated one past the other, cut off (cutting tool)

So something odd is preventing the hatch from being 100%

Caddy
Posts: 40
Joined: Tue May 19, 2015 6:35 pm

How to think strange...

Post by Caddy » Fri Jun 05, 2015 1:38 pm

Hello Eric

It’s very strange. I did more investigations. Allways with copies of the lower polygon (see with thread opening post).

— The behavier stays strange, regardless how many copies I made.
— All the following was done using the enclosing rectangle for selection. No line object were touched directly by the mouse pointer.
— Next I take one of those copies, removed the hatch and convert it to line, looked for the direction of each line, and convert the lines back to a polygon. The behavier stays strange.
— Next I convert the last polygon to lines again, select the lower small horizontal line (by frame), mirrored it, convert to polygon, result: still strange!
— Next, the same procedure as before, result: it looks fine! Why that???? No lines were moved or touched.
— Not knowing why, this bothers me!
Hatches 02.png
Hatches 02.png (7.88 KiB) Viewed 3921 times
Now I'd looked for everthing again. And that's what I found out:

— The left part of the picture shows the line sequence from a copy of the original polygon after converting it to lines. The arrows indicates the direction in the meaning of a clockwise sequence. This sequence leads to the strange results of the hatches.

— The right part of the picture shows the line sequence after mirroring 2 times the horizontal line near the red arrow. But there are 5 more lines where the direction has been changed!! But not by me!! But this anti clockwise sequence leads to the desired result.

BTW. Normally a CAD system should be based at the Cartesian coordinate system. Here in this system the Y-axis is just reverse, depending on the window design rules of the operating system, formerly determined by Apple.

Hubert

Mikerosen
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Location: Seattle, WA, USA
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Re: Hatches...

Post by Mikerosen » Fri Jun 05, 2015 2:46 pm

Hubert,
Your last comment about the Y-axis being reversed is something that has bothered me since the first time I used the program. I told Eric about it, but evidently in his system, it's correct. It's encouraging that you agree with me! Thanks.
Mike Rosen
Seattle, WA, USA

Mac OS 10.13.3, iOS 11 on iPad Pro

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