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Lines disappearing when zooming

Posted: Mon Oct 26, 2009 3:22 pm
by pubgrub
Hi,

I have a problem with the file stored here:

http://rapidshare.com/files/298165004/0.dxf

If I zoom into one of the horizontal lines, they are disappering much earlier than the vertical ones, right when the grids go from 10/100 to 1/10.

QCAD:
Version: 2.2.2.0
[Professional]
Datum: Aug 27 2008
(c) 2001-2008 by RibbonSoft GmbH,
Andrew Mustun
http://www.ribbonsoft.com
Module: Scripting
Qt Version: 4.4.1

OS: Win XP


Thanks,
Mike

Posted: Mon Oct 26, 2009 11:59 pm
by ggsalas

Posted: Tue Oct 27, 2009 12:49 pm
by pubgrub
Ok, I did some more research:

I draw a quite short line, and multiply/rotate it 24 times so I get a nice star. I now can zoom in until almost the whole screen is occupied with lines. When I extend all lines to 1000mm, they start to vanish again quite early during zooming. First the ones almost or exact vertical and horizontal, and at the end only the ones exactly diagonal are left.

btw, my graphics card is an Intel 915GM.

Mike

Posted: Tue Oct 27, 2009 1:07 pm
by ggsalas
Maybe need update QT. Maybe change the 3D aceleration method. I don't know in windows.

Posted: Tue Oct 27, 2009 2:16 pm
by pubgrub
I can't find any qt DLLs for QCad, so i think its compiled into the exe file. Andrew, is that correct?

If so, I can't do an update by myself.

Also, in XP I don't know how I could change the 3d-Acc-Mode. The driver of my graphics adapter doesn't offer any options to change that. Alas, there is no such thing as xorg.conf on these Black-Box-MS-Machinas... :(

btw, one more thing I just realized:

when I scroll the window so that the center of the zoomed star disappears out of view, the before vanished line(s) start to be displayed again - depending on the amount of scrolling.

mike

And I thought I was going mad...

Posted: Thu Feb 25, 2010 9:45 pm
by LeoP
This very same problem (disappearing lines with high zoom level) also happens on my system (W2k, with both Qcad 2.2.2.0 and 2.2.2.1), albeit well after the zoom indication goes from 1/10 to 0.1/1. I have a NVidea TNT2 graphics card. I cannot recall if the same thing happens on the Ubuntu box, but will check that tomorrow.

Line length is definitely in on the equation: longest lines disappear first.
Given the same length, horizontal lines disappear before vertical ones, and vertical ones before diagonal ones. Then again, I have also seen all three disappear at the same time. Might be place/zoom dependant, too.

I can work around this (for the most part) by making my guide lines shorter, but IMHO it should not happen at all. I call it a bug.

Leo

Re: And I thought I was going mad...

Posted: Fri Feb 26, 2010 4:01 pm
by LeoP
LeoP wrote:.... I cannot recall if the same thing happens on the Ubuntu box, but will check that tomorrow.
....
Leo
Just checked: does not happen on the Ubuntu box, not even when a 0.13mm line fills the entire screen.
For reference: that box runs Ubuntu 8.0.4 and is equipped with a ATI Radeon HD 3450 Dual Monitor graphics card.

I will see if there are updated drivers available for the NVidea TNT2 card, maybe the problem lurks there. I just may have to upgrade to a bit more modern hardware for the Windoze box...
Will keep you posted.

Leo

Re: And I thought I was going mad...

Posted: Fri Feb 26, 2010 9:09 pm
by LeoP
LeoP wrote:....
I will see if there are updated drivers available for the NVidea TNT2 card, maybe the problem lurks there.
....
Leo
The good new is, that there were indeed more recent drivers available. The bad news is, that those new drivers did not solve anything. Or it must be that the direction dependancy is gone: all long lines now disappear at the exact same time...

It sure looks like I need a hardware update, but that will take some time though.

Leo

Posted: Fri Aug 13, 2010 9:34 pm
by uwezi
Same thing happens to me - previously on a Win XP Pro system and now on a quite new HP ProBook, Windows 7 Pro, 32bit, internal Intel graphics card with recent drivers.

Lines disappear reproducibly when less than 2% of the full line would be visible. E.g. draw a 10000 units long line and a 100 units long line. Zoom in until the shorter line fills about half the screen and the long line will disappear.

Tested on Ubuntu 10.04: no problem...

Uwe.

Posted: Thu Oct 28, 2010 5:28 pm
by totoetsasoeur
Hi,
I am using 2.2.2.0 under XP. Face to the same problem: line disappear when zooming (exactly as described in this topic).

Any explanation, trick, workaround would be really appreciated.
Thanks
Stephane

Posted: Mon Jun 27, 2011 5:50 pm
by Gwenouille
Hello,

nothing new on this subject ?

This makes QCAD quite useless really: i have to draw plans of a house inmeters, with half centimeter precision, and my lines always disappear when zooming.

I could install @Ubuntu just for that matter, but that is like using a canon to kill a fly !

Posted: Mon Jun 27, 2011 6:29 pm
by andrew
Gwenouille: are you using the latest version of QCAD (2.2.2)?

Posted: Mon Jun 27, 2011 9:58 pm
by Gwenouille
Hi Andrew,

I am using 2.2.2.0
Date: Aug 27 2008
Qt Version: 4.4.1

I was considering to buy it, and then discovered QCAD 3 was about to come out…

I use Win7 64 bits.

Maybe is it worth noticing that not only lines are problematics but other shapes too (circles at least…)

Posted: Wed Jun 29, 2011 5:33 pm
by Gwenouille
Hi, something new on the subject ?
Some way around that bug ?

Posted: Wed Jun 29, 2011 6:01 pm
by andrew
The problem is the very limited drawing area of Windows systems which leads to buffer overflows when zooming in.

QCAD 3 will offer a fix for the problem.