Lines disappearing when zooming

[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

[ggsalas]

Maybe is QT4http://www.ribbonsoft.com/rsforum/viewtopic.php?t=874&highlight=

[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

[ggsalas]

Maybe need update QT. Maybe change the 3D aceleration method. I don't know in windows.

[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

[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

[LeoP]

.... 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

[LeoP]

....
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

[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.

[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

[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 !

[andrew]

Gwenouille: are you using the latest version of QCAD (2.2.2)?

[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…)

[Gwenouille]

Hi, something new on the subject ?
Some way around that bug ?

[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.