QCAD Hatching issues

ChrisBr

Western Thunderer
After reading the reviews and watching Adrian's videos (excellent by the way), I've been drawing up some components for a planned etch. Drawing is no problem and I've been carefully using the snapping functions to ensure no misalignments, but I am having real problems with the fill stage. As soon as I move away from a straightforward rectangle I'm getting "loop not closed" errors.
Even drawing two rectangles with one common side, each will hatch on it's own, select both and I get an error!
Any suggestions as to what I am missing/doing wrong?
 

ChrisBr

Western Thunderer
Yes, it claims the problem lies at the top intersection of the two rectangles. Looking at the connectons, they "appear" to be aligned across and up/down.
Subsequent experiment of drawing a rectangle (which fills ok) and then dividing with a line from mid-point to mid-point results in the same behaviour - 2 rectangles do not fill....
 

ChrisBr

Western Thunderer
Further update - if I draw two rectangles with a "co-incident" middle line (i.e. drawn twice, once for each rectangle) it fills both rectangles, but won't fill either individual rectangle!
 

Scale7JB

Western Thunderer
Have the ends been terminated with each other on the join?

If you have a line that goes beyond its intersect line it won't fill. The lines need to stop at the intersecting line.

JB.
 

ChrisBr

Western Thunderer
So, had another walk through this morning, Sadly, exactly the same results, but this time with screen shots...
Draw rectangle, ensuring the end is aligned with the start -
upload_2018-12-9_9-24-17.png
Then check to ensure it can be hatched ok -
upload_2018-12-9_9-24-47.png
Draw second rectangle, ensuring the start and end are aligned with the corners of the first -
upload_2018-12-9_9-25-31.pngupload_2018-12-9_9-25-38.png

Confirm second rectangle can be hatched on it's own -
upload_2018-12-9_9-26-10.png and in fact first one still hatches..upload_2018-12-9_9-26-29.png
Then, moment of truth,,,, will both hatch?
upload_2018-12-9_9-26-51.png
No!! - here is a zoomed in picture of the alleged problem area - the middle bottom join -
upload_2018-12-9_9-27-42.png
I'm stumped....
 

ChrisBr

Western Thunderer
Well, having borrowed Percy from the Crymlyn A Shop, I appear to have cracked the problem - so for the benefit of anyone else who falls into this "trap" here is the answer....

Each area to be hatched has to have it's own independent bounding box - one line cannot support two areas.

To over come the problem above. I simply drew a second line on top of the first line running vertically between to the two rectangles and all of a sudden I could hatch both together. It seems logical when you think about it, but is different to other drawing packages I use and appears to be undocumented.

One thing to be aware of, if you have too many lines it won't work either.

Thanks JB for wanting to help.
 

Scale7JB

Western Thunderer
I was just about to write something the very same thing.

QCad does seem to be quite strict on its rules in order to work compared to TurboCad where you can just click on an area and it will fill.

With the D16, I imported the dxf file and I'm working on that, but because of the rules, a fair bit of it is having to be redrawn with independent lines. I had a similar problem in areas where one line stretches over three areas, it I have had to delete the line and put in three seperate lines instead.

Glad it's all worked out! It really is a good program.

JB.
 

Scale7JB

Western Thunderer
....and I should add, a fraction of the cost of course, for anyone else weighing up the pro's and cons of which program to invest in.

JB.
 

richard carr

Western Thunderer
Hatching seems to be problematic for most CAD programs. Turbocad still has issues, especially with complex shapes, these often need to be broken down into smaller shapes. It also has 3 different hatching tools the easy one the not so easy one and the if the other 2 fail the pain in the backside one.

When you do the drawing you just need to bear the hatching limitations in mind.

Richard
 

Scale7JB

Western Thunderer
Right, I just thought I would check with my QCad.

Two boxes drawn with 7 lines.
image.jpeg

Manually select the 4 lines of one box
image.jpeg

Fill box no.1
image.jpeg

Manually select the 4 lines of the other box.
image.jpeg

Fill box no.2
image.jpeg

A secondary line to complete box no.2 is not required.

JB.
 

adrian

Flying Squad
A secondary line to complete box no.2 is not required.
Funnily enough I tried the same thing as well. As you have shown select each individually and it will hatch.

However remove the hatching and try again but this time as Chris did - select both rectangles and try and hatch both at the same time. When I do it I get the same error as Chris does.
 

JimG

Western Thunderer
I think I remember having problems with fills in both AutoCAD LT and Draftsight when the drawings were quite complex and I was obviously confusing the algorithm in the programs. I do remember having to draw in extra lines just to get everything correct. If I remember correctly the problem was not on the top side, with no tabs, but on the bottom side with the tabs.

Jim.
 

BrushType4

Western Thunderer
You don’t have to individually select lines. Right click and draw a bounding box around the lines you want to hatch.
 

Big Train James

Western Thunderer
I'm curious why you have drawn two contiguous rectangles, which you want to hatch in one command, rather than one larger rectangle the size of the two together? I am presuming that if you hatch two areas in the same command, they will share the same hatch properties, like color and hatch style? If so, again, why not one larger single rectangle. If having the two boxes is so one can be hatched differently to indicate half-etching or for some other purpose, I would think that would be done in a different color, and as a separate hatch command. Ideally (for me), I would separate lines and hatches for different purposes onto separate layers, but I'm kind of nuts about layers and layer control.

Not a Qcad or Turbocad or Autocad LT user, full on Autocad here. In autocad, I would just click inside the boundary I want to fill with hatch, rather than selecting the boundary itself. Is that not possible with Qcad?

Also, is there not a Rectangle command in Qcad, where you pick points defining opposing corners, which generates a closed boundary by default?

Jim
 

Scale7JB

Western Thunderer
Yes, selecting individual lines when needed is a bit boring rather than a single click inside the desired area.

However, once you have selected your area, it is an instant fill no matter the complexity of the shape, rather than taking the time of putting the kettle on with TC only to find it didn't fill anyway...

There is also the option of drawing by Polyline. I have tried this yet as I've not needed to, but the will allow a single click to select an object and then instant fill.

JB.
 

Ian Smith

Western Thunderer
On the MAC version of QCAD you can double click a line and all of those attached to it will also be selected. This is useful when applying fills, although if as you have in the example of two adjacent rectangles with a common line then you will have the same problem as outlined above (i.e. loop not closed). Effectively, I think a "loop" in this instance can best be imagined as a single continuous line (albeit made up of several individual lines joined end to end at a "node"), if any "node" along that continuous line has more than one entry and one exit line selected then it is no longer a single continuous line.

I hope that makes sense.

Ian
 
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